This document summarizes a study that compared the cancer targeting abilities of doxorubicin-loaded multiwalled carbon nanotubes (MWCNTs) functionalized with either estrone or folic acid. Both in vitro and in vivo experiments using breast cancer cells found that the estrone-functionalized nanotubes showed preferential uptake and greater antitumor activity compared to other formulations, likely due to overexpression of estrogen receptors on the cancer cells. Pharmacokinetic studies also confirmed increased cancer targeting of the ligand-functionalized MWCNTs. The estrone formulation in particular significantly extended survival time in a mouse model compared to free doxorubicin and a control group.
The document describes research on developing doxorubicin-loaded, folic acid-conjugated multi-walled carbon nanotubes (DOX/FA-MWCNTs) for targeted cancer treatment. The nanotubes were engineered through purification, oxidation, and functionalization processes. Doxorubicin was loaded onto the nanotubes through pi-pi stacking interactions. In vitro studies found the DOX/FA-MWCNTs had high drug loading efficiency, controlled release, and preferential uptake by cancer cells. In vivo studies in tumor-bearing rats showed the DOX/FA-MWCNTs improved pharmacokinetics, biodistribution to tumors, and increased survival time compared to free doxorubicin
This document describes a study investigating the cancer targeting potential of docetaxel (DTX) loaded onto multi-walled carbon nanotubes (MWCNTs) conjugated with folic acid (FA) and poly(ethylene glycol) (PEG). DTX was loaded onto both FA-PEG-conjugated MWCNTs (DTX/FA-PEG-MWCNTs) and plain MWCNTs (DTX/MWCNTs). In vitro studies showed the DTX/FA-PEG-MWCNTs had higher cytotoxicity against MCF-7 breast cancer cells and arrested cells in the G2 phase more than DTX/MWCNTs or free drug. Pharmacokinetic studies in mice
This document summarizes an article that appeared in a journal published by Elsevier. The attached copy is provided to the author for non-commercial research and education purposes, including instruction and sharing with colleagues. Other uses such as reproduction, distribution, selling, licensing or posting to third party websites are prohibited. Authors are allowed to post their version of the article to their personal or institutional websites or repositories, with some restrictions. The document provides a link to Elsevier's policies on author rights.
Nanoparticle based oral delivery of vaccinesAshok Patidar
Nanoparticle based oral delivery of vaccines presents an attractive alternative to other delivery routes. Nanoparticles can protect vaccine antigens from gastrointestinal fluids and transport them across the intestinal barrier for uptake by immune cells. Various nanoparticle formulations are being explored as oral vaccine carriers due to their ability to co-deliver antigens and adjuvants. However, challenges remain in ensuring sufficient antigen integrity and transportation. Further development is needed to design robust and scalable nanoparticle vaccine formulations.
Nanoparticles based drug delivery systems for treatment ofaisha rauf
The document discusses nanoparticles for targeting intracellular bacterial infections. It notes that some bacteria can survive and replicate inside cells, avoiding immune responses, making them difficult to treat. Nanoparticles can selectively target and destroy pathogenic bacteria by encapsulating antimicrobial drugs and releasing them at the site of infection. Various types of nanoparticles are investigated for drug delivery, including polymeric nanoparticles, hydrogels, lipid nanoparticles, and metal nanoparticles like gold. Nanoparticles show promise for overcoming antibiotic resistance and improving treatment of intracellular bacterial infections.
Nanoparticulate drug delivery system : recent advancesGayatriTiwaskar
The document discusses nanoparticulate drug delivery systems (NPDDSs). It begins by defining nanoparticles and describing their use in drug delivery. Various types of NPDDS are explored, including polymeric nanoparticles, lipid nanoparticles, metal nanoparticles, dendrimers, liposomes, and more. Their applications in areas like chemotherapy, diabetes, cardiovascular disorders, and more are then reviewed. The advantages of NPDDS include both passive and active drug targeting, increased therapeutic efficacy, controlled release profiles, and high drug loading capacity. Key factors influencing NPDDS design include particle size, drug properties, surface characteristics, biodegradability, and desired drug release. Common preparation methods are also outlined.
This document provides an overview of targeted drug delivery systems. It discusses the reasons for targeted delivery to increase therapeutic effects and reduce toxicity. The ideal properties of targeted delivery carriers and approaches are described. The document outlines different carrier types including vesicular, particulate, cellular, polymeric, and macromolecular systems. It discusses levels of targeting including passive, active, dual and combination approaches. Active targeting can be achieved through ligand-mediated or physical approaches. The document provides examples to illustrate different targeting strategies and carrier types. In summary, it comprehensively reviews concepts and components of targeted drug delivery systems.
Nanomaterials are materials with at least one dimension between 1-100 nm that exhibit unique properties compared to larger materials. They have many applications including in drug delivery due to their high surface area and ability to reach difficult areas of the body smaller than cells. Nanoscale drug delivery systems include nanoparticles, liposomes, dendrimers, polymers, nanoshells, fullerenes, nanotubes, and quantum dots. Liposomes in particular are spherical vesicles consisting of an aqueous core surrounded by a lipid bilayer that can encapsulate both hydrophilic and hydrophobic drugs and provide benefits like controlled release and altered pharmacokinetics. The development of nano-carriers is improving drug therapy by enhancing efficiency and selectivity while reducing side effects
The document describes research on developing doxorubicin-loaded, folic acid-conjugated multi-walled carbon nanotubes (DOX/FA-MWCNTs) for targeted cancer treatment. The nanotubes were engineered through purification, oxidation, and functionalization processes. Doxorubicin was loaded onto the nanotubes through pi-pi stacking interactions. In vitro studies found the DOX/FA-MWCNTs had high drug loading efficiency, controlled release, and preferential uptake by cancer cells. In vivo studies in tumor-bearing rats showed the DOX/FA-MWCNTs improved pharmacokinetics, biodistribution to tumors, and increased survival time compared to free doxorubicin
This document describes a study investigating the cancer targeting potential of docetaxel (DTX) loaded onto multi-walled carbon nanotubes (MWCNTs) conjugated with folic acid (FA) and poly(ethylene glycol) (PEG). DTX was loaded onto both FA-PEG-conjugated MWCNTs (DTX/FA-PEG-MWCNTs) and plain MWCNTs (DTX/MWCNTs). In vitro studies showed the DTX/FA-PEG-MWCNTs had higher cytotoxicity against MCF-7 breast cancer cells and arrested cells in the G2 phase more than DTX/MWCNTs or free drug. Pharmacokinetic studies in mice
This document summarizes an article that appeared in a journal published by Elsevier. The attached copy is provided to the author for non-commercial research and education purposes, including instruction and sharing with colleagues. Other uses such as reproduction, distribution, selling, licensing or posting to third party websites are prohibited. Authors are allowed to post their version of the article to their personal or institutional websites or repositories, with some restrictions. The document provides a link to Elsevier's policies on author rights.
Nanoparticle based oral delivery of vaccinesAshok Patidar
Nanoparticle based oral delivery of vaccines presents an attractive alternative to other delivery routes. Nanoparticles can protect vaccine antigens from gastrointestinal fluids and transport them across the intestinal barrier for uptake by immune cells. Various nanoparticle formulations are being explored as oral vaccine carriers due to their ability to co-deliver antigens and adjuvants. However, challenges remain in ensuring sufficient antigen integrity and transportation. Further development is needed to design robust and scalable nanoparticle vaccine formulations.
Nanoparticles based drug delivery systems for treatment ofaisha rauf
The document discusses nanoparticles for targeting intracellular bacterial infections. It notes that some bacteria can survive and replicate inside cells, avoiding immune responses, making them difficult to treat. Nanoparticles can selectively target and destroy pathogenic bacteria by encapsulating antimicrobial drugs and releasing them at the site of infection. Various types of nanoparticles are investigated for drug delivery, including polymeric nanoparticles, hydrogels, lipid nanoparticles, and metal nanoparticles like gold. Nanoparticles show promise for overcoming antibiotic resistance and improving treatment of intracellular bacterial infections.
Nanoparticulate drug delivery system : recent advancesGayatriTiwaskar
The document discusses nanoparticulate drug delivery systems (NPDDSs). It begins by defining nanoparticles and describing their use in drug delivery. Various types of NPDDS are explored, including polymeric nanoparticles, lipid nanoparticles, metal nanoparticles, dendrimers, liposomes, and more. Their applications in areas like chemotherapy, diabetes, cardiovascular disorders, and more are then reviewed. The advantages of NPDDS include both passive and active drug targeting, increased therapeutic efficacy, controlled release profiles, and high drug loading capacity. Key factors influencing NPDDS design include particle size, drug properties, surface characteristics, biodegradability, and desired drug release. Common preparation methods are also outlined.
This document provides an overview of targeted drug delivery systems. It discusses the reasons for targeted delivery to increase therapeutic effects and reduce toxicity. The ideal properties of targeted delivery carriers and approaches are described. The document outlines different carrier types including vesicular, particulate, cellular, polymeric, and macromolecular systems. It discusses levels of targeting including passive, active, dual and combination approaches. Active targeting can be achieved through ligand-mediated or physical approaches. The document provides examples to illustrate different targeting strategies and carrier types. In summary, it comprehensively reviews concepts and components of targeted drug delivery systems.
Nanomaterials are materials with at least one dimension between 1-100 nm that exhibit unique properties compared to larger materials. They have many applications including in drug delivery due to their high surface area and ability to reach difficult areas of the body smaller than cells. Nanoscale drug delivery systems include nanoparticles, liposomes, dendrimers, polymers, nanoshells, fullerenes, nanotubes, and quantum dots. Liposomes in particular are spherical vesicles consisting of an aqueous core surrounded by a lipid bilayer that can encapsulate both hydrophilic and hydrophobic drugs and provide benefits like controlled release and altered pharmacokinetics. The development of nano-carriers is improving drug therapy by enhancing efficiency and selectivity while reducing side effects
Nanoparticles have potential as drug carriers that fulfill attributes of Ehrlich's "magic bullet" concept by carrying drugs in a stable form to specific disease sites while avoiding non-specific interactions. They can be engineered for active or passive tumor targeting. Active targeting uses ligand-coupled nanoparticles that bind to receptors overexpressed on tumor cells, enhancing drug internalization and treatment efficacy through synergistic effects and bypassing multidrug resistance mechanisms. Passive targeting relies on nanoparticles accumulating in tumors through leaky vasculature via the enhanced permeation and retention effect. Together, active and passive targeting may improve drug delivery for cancer treatment.
Drug targeting aims to selectively deliver drugs to target cells while avoiding non-target cells to maximize therapeutic effects and minimize toxicity. This can be achieved through passive targeting using carriers, active targeting using ligands, or physical targeting exploiting environmental differences between target and non-target sites. The ideal targeted drug delivery system releases drug in a controlled manner at the target site and is non-toxic, biocompatible, and eliminated from the body. Common approaches to drug targeting include carriers, prodrugs, magnetic targeting using magnetic carriers, and monoclonal antibody-based targeting of drug conjugates.
Polymeric nanoparticles can be used to deliver therapeutic nucleic acids like DNA and RNA. They are effective vehicles for gene delivery due to their biocompatibility and ability to protect and release nucleic acids either through diffusion or degradation. Different types of polymers like PLGA, polyanhydrides, chitosan, PEI and PEG can be fabricated into nanospheres, nanocapsules, microspheres or scaffolds to deliver nucleic acids intracellularly or locally at tissue sites. The nucleic acids can then induce expression of therapeutic proteins. The mechanisms of delivery involve either release of nucleic acids from the polymer matrix over time or immobilizing them on substrate polymers for cellular uptake.
NANOTECHNOLOGY comprises technological developments on the nanometer scale, usually 0.1 to 100 nm. Nanotechnology, the science of the small. Nano is Greek for dwarf, and nanoscience deals with the study of molecular and atomic particles.
This document discusses various aspects of nano drug delivery. It describes how nanoscale materials can improve drug bioavailability and minimize side effects by transporting drug molecules to targeted locations. It also discusses how nanotools have been used for medical diagnostics. Different routes of drug administration are outlined including oral, nasal, ophthalmic, parenteral, and others. Targeted drug delivery seeks to optimize a drug's effects by localizing it to the site of action. Nanoparticles can help achieve targeted delivery and enhance transdermal drug applications.
Monoclonal antibodies generated against specific antigens can selectively deliver cytotoxic drugs to cancer cells when conjugated, minimizing damage to normal cells. This allows targeted drug delivery for more effective cancer chemotherapy. The objective of drug targeting is to use a carrier system like monoclonal antibodies to deliver drugs specifically to the site of action. Monoclonal antibodies show promise as drug carriers due to their high specificity for antigens on targeted cells.
This document provides an overview of drug targeting and targeted drug delivery systems. It defines key terms like target, carriers, and ligands. The advantages of drug targeting include minimizing toxicity and maximizing therapeutic effects. An ideal targeted delivery system is biochemically inert, physically and chemically stable, and provides controlled drug release at the target site. Paul Ehrlich's "magic bullet" concept involves using targeting moieties to direct drugs to specific cells. Targeting can be achieved through various carriers and moieties at different levels including passive, active, dual and combination targeting. Challenges include rapid clearance and immune reactions, but targeted systems aim to resolve problems of conventional drug administration like lack of specificity.
The document summarizes a presentation on nanoparticles. It begins with an introduction defining nanoparticles as particulate dispersions between 10-1000nm in size. It then discusses the ideal properties of nanoparticles for drug delivery including stability and non-toxicity. Some advantages are increased therapeutic efficacy and targeted drug delivery. Potential disadvantages include limited targeting abilities and toxicity. Different types of nanoparticles are described such as nanocapsules, nanospheres, solid lipid nanoparticles and polymeric nanoparticles. Methods of preparation include polymerization, ionic gelation and use of preformed polymers. Evaluation methods are also summarized such as assessing particle size, drug content and in vitro drug release.
This document discusses nanoparticles as drug delivery systems. It begins with definitions and concepts, describing nanoparticles as subnanosized colloidal systems ranging from 10-1000 nm that can be used to selectively deliver drugs to target tissues. It then covers the advantages and disadvantages of nanoparticles, ideal characteristics, methods of preparation including cross-linking and polymerization, characterization techniques, applications such as cancer therapy and DNA delivery, and concludes with references.
Nanoparticles targetted drug delivery systemshashankc10
This document discusses different types of nanoparticles used for pharmaceutical applications. It begins by defining nanoparticles as structures between 1-100 nm in size. It then discusses various types of nanoparticles including solid lipid nanoparticles (SLNs), polymeric nanoparticles (PNPs), and nanocrystals. SLNs are described as 10-1000 nm particles composed of solid lipids and surfactants that can encapsulate both hydrophilic and lipophilic drugs. PNPs are similarly sized particles composed of polymeric matrices that can encapsulate or absorb drugs. The document discusses various pharmaceutical applications of these nanoparticles including cancer therapy, drug delivery, and increased drug solubility.
This document discusses controlled drug delivery systems and nano-drug delivery systems. It describes different types of controlled drug delivery systems including smart delivery systems, targeted drug delivery systems, and rate-controlled release systems. It also discusses various nano-carriers used for drug delivery such as liposomes, nanoparticles, dendrimers, and quantum dots. Nano-drug delivery systems help enhance drug efficacy by facilitating uptake, intracellular trafficking, and protection from degradation inside cells. The mechanisms of different nanocarriers for controlled drug release are also summarized.
This document provides an overview of targeted drug delivery systems for cancer. It discusses various types of cancer and factors that contribute to cancer development. It then describes challenges with traditional chemotherapy and discusses how targeted therapies can help address issues like dose-limiting toxicity. Various targeted delivery methods are summarized, including use of monoclonal antibodies, immunoliposomes, nanoparticles, and implantable systems. The document also discusses molecular markers that can help guide targeted therapies and provides examples of FDA-approved targeted drugs.
Nano Drug Delivery Approaches and Importance of Quality by Design (QbD)SABYA SACHI DAS
Different Novel drug delivery systems, their benefits as well as drawbacks.
Different polymers used for preparation of these novel structures:Literature survey.
Targeted drug delivery approaches.
Literature based survey of different nanostructured approaches for drug formulation.
Techniques incvolved for optimization before formulation.
Utilities of quality by design (QbD) approach of optimization.
Drug delivery involves transporting pharmaceutical compounds in the body to safely achieve their desired effects using technologies and systems. It concerns both the quantity and duration of drug presence. For example, protein drugs must be delivered via injection or nano-needles. Nanoparticles like liposomes, dendrimers, fullerenes, nanoshells, quantum dots, and nanorobots can provide targeted drug delivery, improved solubility, constant drug release rates, and increased stability.
Nanomaterial drug delivery updated 20202Tejas Pitale
The document discusses various types of nanoparticles that can be used for drug delivery, including spherical nanoparticles, nanotubes, nanocapsules, nanocrystalline drugs, nanogels, dendrimers, liposomes, polymeric micelles, and polymeric drug conjugates. It describes the properties and applications of each type of nanoparticle. Some key advantages of nanoparticles for drug delivery are their small size, ability to sequester drugs and provide controlled release, lower cytotoxicity, and potential for active targeting to sites in the body. Challenges to nanoparticle drug delivery include biological understanding, safety concerns, manufacturing difficulties, and targeting efficiency.
This document provides an overview of various drug nanocarriers for different routes of drug delivery. It discusses lipid-based nanocarriers including liposomes and emulsions. It also discusses polymer-based nanocarriers such as polymeric micelles, dendrimers, and nanoparticles composed of biodegradable polymers. The document then reviews formation of particles using supercritical carbon dioxide and characterization techniques for drug delivery systems produced via supercritical fluid methods.
- Nanomedicine shows promise as a field of nanotechnology for non-invasive diagnostic imaging, tumor detection, and targeted drug delivery using unique properties of nanoparticles.
- Nanoparticles for drug delivery can be spherical vesicles like liposomes or polymeric nanoparticles, which allow drugs to be attached or incorporated for more effective administration and bioavailability than traditional methods.
- After nanoparticles transport drugs to targeted sites, the drugs are released through various mechanisms to produce therapeutic effects in a sustained and protected manner.
NANO TECHNOLOGY IN DRUG DELIVERY SYSTEMsathish sak
This document discusses how nanoparticles can be used for targeted drug delivery in cancer and inflammation. Nanoparticles less than 100nm in size can be engineered from biodegradable materials to efficiently carry drugs and be taken up by targeted cells. They allow for higher doses of drugs to be delivered directly to diseased cells over prolonged periods of time, reducing side effects. Examples discussed include using nanoparticles to target cancer cells, tumor angiogenesis, infected macrophages, and inflammatory molecules. The future potential of nanotechnology for improved targeted drug delivery is promising.
Application of nanoparticals in drug delivery systemMalay Jivani
This document discusses nanoparticles and their applications in pharmaceuticals, with a focus on using gold nanoparticles (AuNPs) for cancer treatment. It defines nanoparticles and describes some common preparation methods. It then discusses several potential medical applications of nanoparticles, including using them as delivery systems for drugs, genes, and targeting cancer cells. Specifically for AuNPs, it covers their synthesis, properties, and how their surfaces can be functionalized. It describes how AuNPs may be useful for photothermal therapy, radiotherapy, and inhibiting angiogenesis for cancer treatment.
Targeted drug delivery systems aim to increase the concentration of drugs in specific tissues while reducing side effects. The document discusses various drug delivery carrier technologies including lipid-based carriers like liposomes, polymer-based carriers, inorganic nanoparticles, magnetic particles, nucleic acid/peptide carriers, and cell-based delivery systems. It also covers the technology value chain and key innovations in targeted delivery systems for diseases like cancer and neurological disorders. While targeted delivery offers advantages, challenges remain around costs, long-term effects, and developing multi-pronged targeting approaches.
Synthesis and Evaluation of the Cytotoxic and Anti-Proliferative Properties o...IJEAB
Doxorubicin (Dox) is a potent chemotherapeutic agent used in the treatment of cancer. In the present study, pH responsive chitosan polymer coated Dox nanoparticle (Composite) was developed to investigate targeted drug delivery against breast cancer. The anticancer drug DOX-ZnO QDs was loaded to the chitosan nanoparticles. The synthesized free and drug loaded nanoparticle were analyzed using Fourier transmission electron microscopy (FTIR) and UV-Visible spectroscopy(UV-Vis). The particle size was measured using Transmission Electron Microscopy (TEM). Further, the composite was evaluated for its anticancer effects. Drug release analysis showed significantly larger amount of drug released in acidic pH of 5.0 compared to pH 7.4. The composite was significantly more cytotoxic to the breast cancer cells MCF-7 and SKBR-3. The composite was however, less toxic to HEK-293 human embryonic kidney cells confirming minimum side effects on normal cells andcytotoxic to tumor cells. DAPI staining showed nuclear degradation in composite treated breast cancer cells. The cellular uptake of the composite was analyzed by confocal microscopy. The composite induced a G0/G1 phase arrest in breast cancer cells and the number of colonies formed by the composite treated breast cancer cells formed less number of colonies compared to free NP. Our results showed that our composite could serve as a promising therapeutic approach to improve clinical outcomes against various malignancies.
This document reviews interactions between carbon nanotubes (CNTs) and bioactive molecules from a drug delivery perspective. It discusses how CNTs can be purified, oxidized, and dispersed to improve interactions with therapeutics. The review then examines different types of interactions between CNTs and drugs/imaging agents, including hydrophobic interactions, hydrogen bonding, electrostatic interactions, and π-π stacking. It provides examples of how these interactions allow CNTs to efficiently load and deliver various drug cargo molecules. The review concludes that understanding CNT interactions with therapeutics will aid in developing CNT-based nanocarriers for pharmaceutical and biomedical applications.
Nanoparticles have potential as drug carriers that fulfill attributes of Ehrlich's "magic bullet" concept by carrying drugs in a stable form to specific disease sites while avoiding non-specific interactions. They can be engineered for active or passive tumor targeting. Active targeting uses ligand-coupled nanoparticles that bind to receptors overexpressed on tumor cells, enhancing drug internalization and treatment efficacy through synergistic effects and bypassing multidrug resistance mechanisms. Passive targeting relies on nanoparticles accumulating in tumors through leaky vasculature via the enhanced permeation and retention effect. Together, active and passive targeting may improve drug delivery for cancer treatment.
Drug targeting aims to selectively deliver drugs to target cells while avoiding non-target cells to maximize therapeutic effects and minimize toxicity. This can be achieved through passive targeting using carriers, active targeting using ligands, or physical targeting exploiting environmental differences between target and non-target sites. The ideal targeted drug delivery system releases drug in a controlled manner at the target site and is non-toxic, biocompatible, and eliminated from the body. Common approaches to drug targeting include carriers, prodrugs, magnetic targeting using magnetic carriers, and monoclonal antibody-based targeting of drug conjugates.
Polymeric nanoparticles can be used to deliver therapeutic nucleic acids like DNA and RNA. They are effective vehicles for gene delivery due to their biocompatibility and ability to protect and release nucleic acids either through diffusion or degradation. Different types of polymers like PLGA, polyanhydrides, chitosan, PEI and PEG can be fabricated into nanospheres, nanocapsules, microspheres or scaffolds to deliver nucleic acids intracellularly or locally at tissue sites. The nucleic acids can then induce expression of therapeutic proteins. The mechanisms of delivery involve either release of nucleic acids from the polymer matrix over time or immobilizing them on substrate polymers for cellular uptake.
NANOTECHNOLOGY comprises technological developments on the nanometer scale, usually 0.1 to 100 nm. Nanotechnology, the science of the small. Nano is Greek for dwarf, and nanoscience deals with the study of molecular and atomic particles.
This document discusses various aspects of nano drug delivery. It describes how nanoscale materials can improve drug bioavailability and minimize side effects by transporting drug molecules to targeted locations. It also discusses how nanotools have been used for medical diagnostics. Different routes of drug administration are outlined including oral, nasal, ophthalmic, parenteral, and others. Targeted drug delivery seeks to optimize a drug's effects by localizing it to the site of action. Nanoparticles can help achieve targeted delivery and enhance transdermal drug applications.
Monoclonal antibodies generated against specific antigens can selectively deliver cytotoxic drugs to cancer cells when conjugated, minimizing damage to normal cells. This allows targeted drug delivery for more effective cancer chemotherapy. The objective of drug targeting is to use a carrier system like monoclonal antibodies to deliver drugs specifically to the site of action. Monoclonal antibodies show promise as drug carriers due to their high specificity for antigens on targeted cells.
This document provides an overview of drug targeting and targeted drug delivery systems. It defines key terms like target, carriers, and ligands. The advantages of drug targeting include minimizing toxicity and maximizing therapeutic effects. An ideal targeted delivery system is biochemically inert, physically and chemically stable, and provides controlled drug release at the target site. Paul Ehrlich's "magic bullet" concept involves using targeting moieties to direct drugs to specific cells. Targeting can be achieved through various carriers and moieties at different levels including passive, active, dual and combination targeting. Challenges include rapid clearance and immune reactions, but targeted systems aim to resolve problems of conventional drug administration like lack of specificity.
The document summarizes a presentation on nanoparticles. It begins with an introduction defining nanoparticles as particulate dispersions between 10-1000nm in size. It then discusses the ideal properties of nanoparticles for drug delivery including stability and non-toxicity. Some advantages are increased therapeutic efficacy and targeted drug delivery. Potential disadvantages include limited targeting abilities and toxicity. Different types of nanoparticles are described such as nanocapsules, nanospheres, solid lipid nanoparticles and polymeric nanoparticles. Methods of preparation include polymerization, ionic gelation and use of preformed polymers. Evaluation methods are also summarized such as assessing particle size, drug content and in vitro drug release.
This document discusses nanoparticles as drug delivery systems. It begins with definitions and concepts, describing nanoparticles as subnanosized colloidal systems ranging from 10-1000 nm that can be used to selectively deliver drugs to target tissues. It then covers the advantages and disadvantages of nanoparticles, ideal characteristics, methods of preparation including cross-linking and polymerization, characterization techniques, applications such as cancer therapy and DNA delivery, and concludes with references.
Nanoparticles targetted drug delivery systemshashankc10
This document discusses different types of nanoparticles used for pharmaceutical applications. It begins by defining nanoparticles as structures between 1-100 nm in size. It then discusses various types of nanoparticles including solid lipid nanoparticles (SLNs), polymeric nanoparticles (PNPs), and nanocrystals. SLNs are described as 10-1000 nm particles composed of solid lipids and surfactants that can encapsulate both hydrophilic and lipophilic drugs. PNPs are similarly sized particles composed of polymeric matrices that can encapsulate or absorb drugs. The document discusses various pharmaceutical applications of these nanoparticles including cancer therapy, drug delivery, and increased drug solubility.
This document discusses controlled drug delivery systems and nano-drug delivery systems. It describes different types of controlled drug delivery systems including smart delivery systems, targeted drug delivery systems, and rate-controlled release systems. It also discusses various nano-carriers used for drug delivery such as liposomes, nanoparticles, dendrimers, and quantum dots. Nano-drug delivery systems help enhance drug efficacy by facilitating uptake, intracellular trafficking, and protection from degradation inside cells. The mechanisms of different nanocarriers for controlled drug release are also summarized.
This document provides an overview of targeted drug delivery systems for cancer. It discusses various types of cancer and factors that contribute to cancer development. It then describes challenges with traditional chemotherapy and discusses how targeted therapies can help address issues like dose-limiting toxicity. Various targeted delivery methods are summarized, including use of monoclonal antibodies, immunoliposomes, nanoparticles, and implantable systems. The document also discusses molecular markers that can help guide targeted therapies and provides examples of FDA-approved targeted drugs.
Nano Drug Delivery Approaches and Importance of Quality by Design (QbD)SABYA SACHI DAS
Different Novel drug delivery systems, their benefits as well as drawbacks.
Different polymers used for preparation of these novel structures:Literature survey.
Targeted drug delivery approaches.
Literature based survey of different nanostructured approaches for drug formulation.
Techniques incvolved for optimization before formulation.
Utilities of quality by design (QbD) approach of optimization.
Drug delivery involves transporting pharmaceutical compounds in the body to safely achieve their desired effects using technologies and systems. It concerns both the quantity and duration of drug presence. For example, protein drugs must be delivered via injection or nano-needles. Nanoparticles like liposomes, dendrimers, fullerenes, nanoshells, quantum dots, and nanorobots can provide targeted drug delivery, improved solubility, constant drug release rates, and increased stability.
Nanomaterial drug delivery updated 20202Tejas Pitale
The document discusses various types of nanoparticles that can be used for drug delivery, including spherical nanoparticles, nanotubes, nanocapsules, nanocrystalline drugs, nanogels, dendrimers, liposomes, polymeric micelles, and polymeric drug conjugates. It describes the properties and applications of each type of nanoparticle. Some key advantages of nanoparticles for drug delivery are their small size, ability to sequester drugs and provide controlled release, lower cytotoxicity, and potential for active targeting to sites in the body. Challenges to nanoparticle drug delivery include biological understanding, safety concerns, manufacturing difficulties, and targeting efficiency.
This document provides an overview of various drug nanocarriers for different routes of drug delivery. It discusses lipid-based nanocarriers including liposomes and emulsions. It also discusses polymer-based nanocarriers such as polymeric micelles, dendrimers, and nanoparticles composed of biodegradable polymers. The document then reviews formation of particles using supercritical carbon dioxide and characterization techniques for drug delivery systems produced via supercritical fluid methods.
- Nanomedicine shows promise as a field of nanotechnology for non-invasive diagnostic imaging, tumor detection, and targeted drug delivery using unique properties of nanoparticles.
- Nanoparticles for drug delivery can be spherical vesicles like liposomes or polymeric nanoparticles, which allow drugs to be attached or incorporated for more effective administration and bioavailability than traditional methods.
- After nanoparticles transport drugs to targeted sites, the drugs are released through various mechanisms to produce therapeutic effects in a sustained and protected manner.
NANO TECHNOLOGY IN DRUG DELIVERY SYSTEMsathish sak
This document discusses how nanoparticles can be used for targeted drug delivery in cancer and inflammation. Nanoparticles less than 100nm in size can be engineered from biodegradable materials to efficiently carry drugs and be taken up by targeted cells. They allow for higher doses of drugs to be delivered directly to diseased cells over prolonged periods of time, reducing side effects. Examples discussed include using nanoparticles to target cancer cells, tumor angiogenesis, infected macrophages, and inflammatory molecules. The future potential of nanotechnology for improved targeted drug delivery is promising.
Application of nanoparticals in drug delivery systemMalay Jivani
This document discusses nanoparticles and their applications in pharmaceuticals, with a focus on using gold nanoparticles (AuNPs) for cancer treatment. It defines nanoparticles and describes some common preparation methods. It then discusses several potential medical applications of nanoparticles, including using them as delivery systems for drugs, genes, and targeting cancer cells. Specifically for AuNPs, it covers their synthesis, properties, and how their surfaces can be functionalized. It describes how AuNPs may be useful for photothermal therapy, radiotherapy, and inhibiting angiogenesis for cancer treatment.
Targeted drug delivery systems aim to increase the concentration of drugs in specific tissues while reducing side effects. The document discusses various drug delivery carrier technologies including lipid-based carriers like liposomes, polymer-based carriers, inorganic nanoparticles, magnetic particles, nucleic acid/peptide carriers, and cell-based delivery systems. It also covers the technology value chain and key innovations in targeted delivery systems for diseases like cancer and neurological disorders. While targeted delivery offers advantages, challenges remain around costs, long-term effects, and developing multi-pronged targeting approaches.
Synthesis and Evaluation of the Cytotoxic and Anti-Proliferative Properties o...IJEAB
Doxorubicin (Dox) is a potent chemotherapeutic agent used in the treatment of cancer. In the present study, pH responsive chitosan polymer coated Dox nanoparticle (Composite) was developed to investigate targeted drug delivery against breast cancer. The anticancer drug DOX-ZnO QDs was loaded to the chitosan nanoparticles. The synthesized free and drug loaded nanoparticle were analyzed using Fourier transmission electron microscopy (FTIR) and UV-Visible spectroscopy(UV-Vis). The particle size was measured using Transmission Electron Microscopy (TEM). Further, the composite was evaluated for its anticancer effects. Drug release analysis showed significantly larger amount of drug released in acidic pH of 5.0 compared to pH 7.4. The composite was significantly more cytotoxic to the breast cancer cells MCF-7 and SKBR-3. The composite was however, less toxic to HEK-293 human embryonic kidney cells confirming minimum side effects on normal cells andcytotoxic to tumor cells. DAPI staining showed nuclear degradation in composite treated breast cancer cells. The cellular uptake of the composite was analyzed by confocal microscopy. The composite induced a G0/G1 phase arrest in breast cancer cells and the number of colonies formed by the composite treated breast cancer cells formed less number of colonies compared to free NP. Our results showed that our composite could serve as a promising therapeutic approach to improve clinical outcomes against various malignancies.
This document reviews interactions between carbon nanotubes (CNTs) and bioactive molecules from a drug delivery perspective. It discusses how CNTs can be purified, oxidized, and dispersed to improve interactions with therapeutics. The review then examines different types of interactions between CNTs and drugs/imaging agents, including hydrophobic interactions, hydrogen bonding, electrostatic interactions, and π-π stacking. It provides examples of how these interactions allow CNTs to efficiently load and deliver various drug cargo molecules. The review concludes that understanding CNT interactions with therapeutics will aid in developing CNT-based nanocarriers for pharmaceutical and biomedical applications.
This document reviews interactions between carbon nanotubes (CNTs) and bioactive molecules from a drug delivery perspective. It discusses how CNTs can be purified and functionalized through oxidation and other surface modifications to improve dispersion and introduce functional groups for conjugating bioactives. The review then examines different types of physical and chemical interactions that can occur between therapeutics and CNTs, such as hydrophobic interactions, hydrogen bonding, and pi-pi stacking. These interactions enable CNTs to act as carriers for drug and gene delivery. The review aims to provide an understanding of CNTs' potential as pharmaceutical nanocarriers and safety/toxicity considerations.
This study aimed to (1) identify degradation products of the chemotherapy drug doxorubicin under forced degradation conditions and (2) determine if silk films can stabilize doxorubicin and prevent degradation over time. Doxorubicin solutions were subjected to acid, base, heat, and oxidation stress and degradation products were identified using LC-MS. A degradation product was found under acidic and heat conditions that increased over time. Higher drug concentrations degraded faster. Additional studies of drug-bound silk films and films under stress are being analyzed to see if silk prevents degradation and most drug remains intact long-term. Local drug delivery using silk films could overcome challenges of systemic chemotherapy if silk stabilizes drugs.
Formulation and in vitro evaluation of quercetin loaded carbon nanotubes for ...IRJET Journal
This document presents a study that formulated and evaluated quercetin-loaded carbon nanotubes for cancer targeting. Specifically, it:
1) Developed a quercetin-loaded drug delivery system using functionalized single-walled carbon nanotubes conjugated with chitosan.
2) Found that the highest drug loading efficiency of 38% was achieved at 4°C and with an equal initial weight ratio of drug to carrier.
3) Demonstrated that the drug delivery system was stable under neutral pH but effectively released quercetin under acidic pH similar to the tumor environment.
4) Showed that the quercetin-conjugated carrier had significantly higher cytotoxicity against HeLa
Experimental and theoretical solubility advantage screening of bi-component s...Maciej Przybyłek
This document describes an experimental and theoretical study to screen potential solubilizers for curcumin. In the experimental phase, the solubility of curcumin was measured in binary mixtures with 24 excipients. The highest solubility enhancement was found with pyrogallol, caffeine, theophylline, and nicotinamide. A theoretical QSPR model was then developed using molecular descriptors to predict solubility. This model was applied to screen over 230,000 compounds and predict solubility for curcumin analogs and naturally occurring turmerones to identify new excipients.
Development and characterization of anionic liposaccharides for enhanced oralAdel Abdelrahim, PhD
The document describes the development and characterization of novel anionic liposaccharide derivatives for enhancing oral drug delivery. Liposaccharides containing d-glucose and lipoamino acids were synthesized. Their critical aggregation concentration and thermodynamic profiles were determined using isothermal titration microcalorimetry. The liposaccharides were found to be non-toxic and did not cause hemolysis or reduce cell viability. When mixed with the model drug tobramycin, one of the liposaccharides formed aggregates around 200 nm and increased tobramycin's partitioning between n-octanol and water, suggesting it may enhance the oral absorption of hydrophilic drugs.
This document discusses polymeric micelles for drug delivery applications. It explains that amphiphilic polymers can self-assemble above a critical micelle concentration to form micelles with a hydrophobic core and hydrophilic shell. Doxorubicin-loaded polymeric micelles were developed using poloxamer 407, with sizes around 23 nm and high drug encapsulation. The micelles were modified to attach two FLT3 peptides, CKR and EVQ, to target leukemic stem cells and increase cytotoxicity compared to free doxorubicin. These peptide-conjugated polymeric micelles show potential as a targeted drug delivery system for acute myeloid leukemia treatment.
Impact of carbon nanomaterials on the formation of multicellular spheroids by...Татьяна Гергелюк
This paper investigates the effect of different concentrations of nanostructured materials: fullerene-like (С60), onion-like carbon (OLC) and ultra dispersed diamonds (UDD) on the formation of multicellular spheroids (MS). Chemical composition and purity of nanomaterials is controlled by Fourier transform infrared spectroscopy (FT-IR). The strength and direction of the impact of nanomaterials on the cell population was assessed using microphotography of multicellular spheroids culture and Pearson's correlation coefficient. The results demonstrated that UDD and OLC reduced adhesion and cohesive ability of cells and stimulated generation of cell spheroids of ~ 3 ∙ 10 mm3 in significant amount. The fullerenes reduced in the main cell adhesion to substrate that led to formation of cell aggregates of ~ 5 ∙ 10-3 mm3. The results could be useful for achievement of the directed cell growth in three-dimensional culture.
Impact of carbon nanomaterials on the formation of multicellular spheroids by...Татьяна Гергелюк
This paper investigates the effect of different concentrations of nanostructured materials: fullerene-like (С60), onion-like carbon
(OLC) and ultra dispersed diamonds (UDD) on the formation of multicellular spheroids (MS). Chemical composition and purity of
nanomaterials is controlled by Fourier transform infrared spectroscopy (FT-IR). The strength and direction of the impact of
nanomaterials on the cell population was assessed using microphotography of multicellular spheroids culture and Pearson's correlation
coefficient. The results demonstrated that UDD and OLC reduced adhesion and cohesive ability of cells and stimulated generation of cell
spheroids of ~ 3 ∙ 10 mm3 in significant amount. The fullerenes reduced in the main cell adhesion to substrate that led to formation of
cell aggregates of ~ 5 ∙ 10-3 mm3. The results could be useful for achievement of the directed cell
The document describes the development and evaluation of doxorubicin-loaded liposomes and phosphatidylethanolamine-conjugated liposomes. Liposomes were prepared using the lipid film hydration method and characterized for size, zeta potential, drug loading efficiency, and drug release kinetics. In vitro drug release studies showed 69.91% and 77.07% of doxorubicin was released from doxorubicin-loaded liposomes and phosphatidylethanolamine-conjugated liposomes, respectively, over nine hours. Fluorescence microscopy indicated the liposomes accumulated in the liver, lungs, and kidneys of treated rats.
This document discusses curcumin nanoparticles and their potential efficacy against human pathogens. It begins with an introduction about curcumin and its various medical applications. It then describes several common methods for preparing curcumin nanoparticles, including the nanoprecipitation method. The document discusses the physicochemical properties of curcumin and examines approaches to improve its bioavailability, such as using nanoparticles, micelles, liposomes and nanoemulsions. It focuses on dendrosomal nano-curcumin as a promising formulation to enhance curcumin's stability, solubility, and anti-tumor effects both in vitro and in vivo.
This research article summarizes a study encapsulating curcumin, a natural anti-cancer compound, in polymeric micelles for cancer therapy. The researchers synthesized a diblock copolymer micelle (PNPC) from methoxy polyethylene glycol and oleic acid to encapsulate curcumin. They showed that PNPC had high drug loading efficiency and stability. In vitro, PNPC significantly suppressed the proliferation of breast and liver cancer cell lines. In an animal model of breast cancer, PNPC treatment reduced tumor incidence and size compared to controls. PNPC also increased expression of pro-apoptotic genes and decreased expression of anti-apoptotic and proliferative genes in the tumors. The results suggest PNPC is a
Nanoparticles in lung cancer treatment and diagnosis.mohamedAhmed1628
1. The document discusses recent advances in using nanoparticles for the diagnosis and treatment of lung cancer.
2. It outlines different types of nanoparticles like liposomes, polymer nanoparticles, dendrimers, gold nanoparticles, and silica nanoparticles that have been used to target lung cancer cells and enhance drug delivery.
3. Recent applications show these nanoparticles can help increase drug concentrations in tumors, induce cancer cell apoptosis, and selectively target cancer cells while reducing side effects - showing promise for improved lung cancer treatment.
1. The document discusses using porous silicon microspheres functionalized with antibodies for targeted cancer therapy. The particles are coated with a silica layer that protects them but can be degraded inside cells, causing the particles to react violently and kill the cells.
2. The particles are functionalized with antibodies that target the HER2 receptor, which is overexpressed on some breast cancer cells. Testing shows the antibody-functionalized particles selectively kill cells overexpressing HER2 while having little effect on other cells.
3. The targeted particles are a promising approach for cancer therapy as they can be selectively taken up by and destroy only cancer cells overexpressing the targeted receptor.
This study aimed to develop more effective drug delivery systems for cancer treatment by correlating the surface characteristics of drug carriers to their efficacy. Doxorubicin was loaded into soybean oil- and Mygliol 812-based liposomal formulations. Synchrotron small-angle X-ray scattering revealed that doxorubicin loading yielded an abraded surface on the soybean oil formulation. In vitro tests found this formulation more effectively reduced survival of carcinoma cells. A dialysis assay also showed a higher initial burst release of doxorubicin from the soybean oil carriers. The results suggest matching the surface geometry of drug carriers to target cells could help refine development of more effective delivery systems with fewer side effects. This is
This document provides a protocol for engineering cells with intracellular drug-loaded microparticles to control cell phenotype. Key points:
- Microparticles (~1 μm) loaded with drugs, iron oxide, or fluorescent dyes are synthesized using PLGA and single emulsion evaporation.
- The microparticles can be engineered to have positive or negative surface charges and different sizes to optimize cell uptake.
- Mesenchymal stem cells efficiently internalize and retain the microparticles for weeks, allowing sustained control of cell phenotype.
- Loaded drugs are released from the microparticles inside the cells and can modify neighboring cell phenotypes in a paracrine manner.
- Particle-engineered cells can be tracked by MRI for over 12
This document provides a protocol for engineering cells with intracellular drug-loaded microparticles to control cell phenotype. Key points:
- Microparticles (~1 μm) loaded with drugs, iron oxide, or fluorescent dyes are synthesized using PLGA and single emulsion evaporation.
- The microparticles can be modified with antibodies or polycations to improve cell uptake.
- Mesenchymal stem cells (MSCs) efficiently internalize and retain the microparticles for weeks, allowing sustained control of cell phenotype.
- Loaded drugs can induce differentiation of engineered and neighboring cells. Iron oxide allows tracking of engineered MSCs by MRI for over 12 days.
- The protocol generates and characterizes drug-loaded microparticles then
This document describes a technique for engineering cells with intracellular drug-loaded microparticles to control cell phenotype after transplantation. Key points:
- Microparticles 1um in diameter can remain inside mesenchymal stem cells for weeks, providing sustained control of phenotype. In contrast, nanoparticles are often quickly exocytosed.
- Drug-loaded microparticles have been used to induce osteogenic differentiation of stem cells and enable longitudinal tracking of cell location via MRI.
- The protocol provides methods for generating drug-loaded poly(lactic-co-glycolic acid) microparticles, engineering cells to take up particles, and analyzing drug loading and release.
- While most studies have focused on hydrophobic small molecules, adapting the
This document provides a protocol for engineering cells with intracellular drug-loaded microparticles to control cell phenotype. Key points:
- Microparticles (~1 μm) loaded with drugs, iron oxide, or fluorescent dyes are synthesized using PLGA and single emulsion evaporation.
- The microparticles can be engineered to have positive or negative surface charges and different sizes to optimize cell uptake.
- Mesenchymal stem cells efficiently internalize and retain the microparticles for weeks, allowing sustained control of cell phenotype.
- Loaded drugs are released from the microparticles inside the cells and can alter cell behavior through paracrine and endocrine effects.
- Particle-engineered cells can be tracked by MRI for over
2. MWCNTs employing breast cancer cells on Balb/c mice. The
cancerous cells overexpress the folate receptors (FRs) and
estrogen receptors (ERs) belonging to folate and nuclear
hormone receptor superfamily, respectively.26
The MWCNTs
tethering ES and FA probably deliver DOX more efficiently
into the cancerous cells after binding selectively to their
respective receptors through endocytosis or tiny nanoneedle
mechanism. The ligand-driven MWCNTs are an established,
well-known concept, and these targeting moieties can be easily
attached to f-MWCNTs. The comparative cancer targeting
propensity of targeting ligand conjugated f-MWCNTs studied
on a single platform reported herein is expected to be of greater
scientific interest in targeted drug delivery. We have extensively
characterized the ligand (ES and FA) conjugated MWCNTs in
vitro, ex vivo, and in vivo in terms of biodistribution and
pharmacokinetics, Kaplan−Meier survival analysis, and tumor
targeting efficacy on Balb/c mice.
2. MATERIALS AND METHODS
2.1. Materials. Multiwalled carbon nanotubes (MWCNTs)
produced by chemical vapor deposition (CVD) with purity
99.3% were purchased from Sigma-Aldrich Pvt. Ltd. (St. Louis,
Missouri, USA). Doxorubicin hydrochloride was received as a
benevolent gift from M/s Sun Pharm Advanced Research
Centre (SPARC), Vadodara, India. Folic acid (FA), dimethyl
sulfoxide (DMSO), 1-ethyl-3-(3-dimethylaminopropyl)-
carbodiimide (EDC), and dialysis membrane (MWCO, 5−6
kDa) were purchased from HiMedia Pvt. Ltd. Mumbai, India.
Estrone (ES) was purchased from Sigma-Aldrich Pvt. Ltd. USA.
All the reagents and solvents were used as received.
2.2. Functionalization of MWCNTs. The procured
pristine MWCNTs were initially purified and treated with
strong oxidizing acid following a previously reported method
from our and other laboratories after minor modifica-
tions.2,4,10,13,27,28
Briefly, MWCNTs (500 mg) were treated
with concentrated nitric acid and sulfuric acid
(HNO3:H2SO4::1:3) mixture with continuous magnetic stirring
at 100 rpm (Remi, Mumbai, India) maintaining 100 ± 5 °C
temperature for 24 h. Then dispersed MWCNTs were washed
with deionized water, ultracentrifuged, vacuum-dried, and
collected. Treated MWCNTs (300 mg) were further treated
with ammonium hydroxide (NH4OH) and hydrogen peroxide
(H2O2) in 50:50 ratio in a round-bottom flask (RBF) at 80 ± 5
°C for 24 h. The treated oxidized MWCNTs (ox-MWCNTs)
were repeatedly washed to neutral pH, ultracentrifuged
(Z36HK, HERMLE LaborTchnik GmbH, Germany) at
20,000 rpm for 15 min, and finally lyophilized (Heto dry
Winner, Germany).
2.3. Conjugation of Estrone to Surface Functionalized
MWCNTs (ES-PEG-MWCNTs). The conjugation of estrone
(ES) with oxidized-MWCNTs was performed using standard 1-
ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) chemis-
try in three steps following the previously reported methods
after minor modifications.23,27,29
2.4. Activation of Estrone. Briefly, estrone (ES; 8 mM),
succinic anhydride (SA; 10 mM), dimethylaminopyridine
(DMAP; 8 mM), and triethylamine (TEA; 8 mM) were
dissolved in dioxane and magnetically stirred overnight at 25 ±
2 °C. The dioxane was evaporated under vacuum, and the
obtained residue was dissolved in dichloromethane (DCM) and
filtered. The filtrate was further dried and precipitated using
diethyl ether to obtain the carboxylic acid derivative of estrone
(ES-COOH). The ES-COOH (0.5 mM) was dissolved in
DCM (0.5 mM) in equimolar concentration, and hydrox-
ybenzotriazole (HOBT; 0.1 mM), PEG-3000-amine, and DCC
were added to it and continually magnetically stirred at 25 ± 2
°C for 24 h until precipitate was formed. The pellet of ES-PEG-
NH2 was collected by centrifugation (Scheme 1), repeatedly
washed with deionized water, and collected.23,30
The COOH-MWCNTs (33.36 mg) and EDC (6.41 mg)
were dissolved in DMSO with continuous magnetic stirring at
100 rpm. After 6 h, ES-PEG-NH2 in DMSO (4.60 mg/mL)
solution was added and kept magnetic stirred up to 5 days.
Then the unreacted biproducts/materials were separated out,
lyophilized (Heto dry Winner, Denmark, Germany), collected,
and stored (Scheme 2).27
2.5. Synthesis of FA-PEG Conjugation to Function-
alized MWCNTs. The tert-butoxycarbonyl (t-Boc)-protected
folic acid (FA) for amine protection of FA was synthesized, and
its further activation was performed following the previously
reported well-known method to obtain t-Boc-FA-NHS.2,31
2.5.1. Conjugation of t-Boc-FA to Surface Functionalized
MWCNTs. The t-Boc-FA-NHS (16.25 mg) was mixed with
PEG-3k bis amine (Sigma-Aldrich, USA) (225.0 mg) in DMSO
in the presence of triethylamine (TEA) and magnetically stirred
for 24 h at 25 ± 2 °C. The obtained t-Boc-FA-PEG-NH2 as a
pale yellow solid was collected and dried.
The t-Boc-FA-PEG-NH2 was mixed with ox-MWCNTs in
DMSO followed by addition of EDC and continually
magnetically stirred for 5 days maintaining the dark condition
at 25 ± 2 °C (Scheme 3). The resultant conjugate was
collected, dried, and characterized by FTIR spectroscopy.2,10,32
The activation and conjugation of both ligands with
MWCNTs were extensively characterized by UV/vis spectros-
copy (Shimadzu 1601, UV−visible spectrophotometer, Shi-
madzu, Japan), and Fourier transform infrared spectroscopy
(FTIR) was performed using the KBr pellet method
(PerkinElmer 783, Pyrogon 1000 spectrophotometer, USA)
scanned in the range from 4000 to 500 cm−1
.
2.6. Characterization of the MWCNT Conjugates. The
developed MWCNT conjugates were characterized for particle
size by photon correlation spectroscopy in a Malvern Zetasizer
nano ZS90 (Malvern Instruments, Ltd., Malvern, U.K.) at room
Scheme 1. Conjugation of PEG to Activated Estrone
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
631
3. temperature, atomic force microscope (AFM) using Digital
Nanoscope IV Bioscope (Veeco Innova Instruments, Santa
Barbara, CA, USA), FTIR spectroscopy using PerkinElmer
FTIR spectrophotometer (PerkinElmer 783, Pyrogon 1000
Spectrophotometer, Shelton, Connecticut), 1
H nuclear mag-
netic resonance (NMR) spectroscopy (Bruker, DRX, USA),
and Raman spectroscopy RINSHAW, inVia Raman spectro-
photometer (Renishaw, Gloucestershire, U.K.).
2.7. DOX Loading Studies. DOX was loaded into the
MWCNT dispersion using modified equilibrium dialysis
method as reported previously.10,15,25
Briefly, DOX was initially
dissolved in acetone, and aqueous triethylamine (TEA)
solution was added in a 2:1 molar ratio (DOX:TEA). The
DOX was magnetically stirred (100 rpm; Remi, India) with the
developed MWCNT conjugates and pristine MWCNTs in
phosphate buffer solution (PBS: pH 7.4) using Teflon beads
overnight at 37 ± 0.5 °C for 24 h to facilitate DOX loading.
MWCNT conjugates were then ultracentrifuged until the
nanotube dispersion became color free. The amount of
unbound DOX was determined measuring absorbance at λmax
480.2 nm spectrophotometrically (Shimadzu 1601, UV−visible
spectrophotometer, Shimadzu, Japan). The developed DOX
loaded MWCNT (DOX/MWCNTs, DOX/ox-MWCNTs,
DOX/ES-PEG-MWCNTs, and DOX/FA-PEG-MWCNTs)
conjugates were collected, dried, lyophilized (Heto dry Winner,
Denmark, Germany), and stored at 2−8 °C for further use. The
DOX loading efficiency (%) was calculated using the following
formula:
Scheme 2. Development of ES-PEG-MWCNT Conjugate
Scheme 3. Conjugation Scheme of FA-PEG and ES-PEG Conjugated MWCNTs
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
632
4. =
−
×
% loading efficiency
wt of loaded DOX wt of free DOX
wt of loaded DOX
100
2.8. In Vitro Release Studies. The dispersion of DOX/
MWCNT, DOX/ox-MWCNT, DOX/ES-PEG-MWCNT, and
DOX/FA-PEG-MWCNT conjugates was studied in sodium
acetate buffer saline (pH 5.3) and phosphate buffer saline (pH
7.4) as recipient media using a modified dissolution method
with maintenance of 37 ± 0.5 °C physiological temperature.
The MWCNT conjugates were filled in pretreated dialysis
membrane (MWCO 5−6 kDa, HiMedia, Mumbai, India)
separately and kept in the releasing media under constant
magnetic stirring (100 rpm; Remi, Mumbai, India) at 37 ± 0.5
°C. At definite time points, the MWCNT samples were
withdrawn, and after each sampling, the withdrawn medium
was replenished with fresh sink solution maintaining strict sink
condition. The drug concentration was determined after proper
dilution in a UV/visible spectrophotometer at λmax 480.2 nm
(UV/vis, Shimadzu 1601, Kyoto, Japan).
2.9. Ex Vivo (Cell Line) Studies. The ex vivo (cell line)
studies were performed on Michigan Cancer Foundation
human breast cancer cells (MCF-7) cell line procured from
National Center for Cell Sciences (NCCS), Pune, India. The
MCF-7 cells were maintained in Dulbecco’s modified Eagle’s
medium (DMEM; HiMedia, Mumbai, India) containing 10%
fetal bovine serum (FBS; Sigma, St. Louis, Missouri)
supplemented with 1% antibiotic (penicillin−streptomycin)
solution grown to confluence in humidified atmosphere
containing 5% CO2 at 37 °C. Cells were seeded at a density
of 4 × 103
cells/well and incubated for 24 h prior to
commencement of the experiments. The DMEM medium was
changed as per requirement every alternate day, and cells with
approximately 80% confluence were used for further studies.
After that, medium was decanted and washed with fresh PBS (6
mL for 25 cm2
) and cells were trypsinized using 0.25% trypsin
solution. Trypsin was removed completely, and subsequently
medium was added to split the cells.4,14
2.10. Cell Viability Assay. The cell viability assay was
performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-
zolium bromide (MTT) dye reduction assay to a blue formazan
derivative by living cells to assess the cytotoxic propensity of
the nanotube formulations at different concentrations.27,28,33
Briefly, MCF-7 cells were placed onto 96-well flat-bottomed
tissue culture plates (Sigma, Germany) and allowed to adhere
for 24 h at 37 °C prior to assay. The cells in quadruplicate were
treated with free DOX, DOX/MWCNTs, DOX/ox-MWCNTs,
DOX/FA-PEG-MWCNTs, and DOX/ES-PEG-MWCNTs
with increasing concentration (0.001−100 μM) of DOX
simultaneously under controlled environment for 24 and 48 h
at 37 ± 0.5 °C in a humidified atmosphere with 5% CO2.
Thereafter, medium was decanted and 50 μL of methylthiazole
tetrazolium (MTT; 1 mg/mL) in DMEM (10 μL; 5 mg/mL in
Hanks balanced salt solution; without phenol red) was added to
each well and incubated for 4 h at 37 °C. Formazan crystals
were solubilized in 50 μL of isopropanol by shaking at rt for 10
min. The absorbance was taken using a microplate reader
(Medispec Ins. Ltd., Mumbai, India) at 570 nm wavelength,
blanked with DMSO solution, and (%) cell viability was
calculated using the following formula:
= ×cell viability (%)
[A]
[A]
100test
control
where [A]test is the absorbance of the test sample and [A]control
is the absorbance of control samples.
2.11. Cell Uptake Study. Cellular uptake studies were
carried out through flow cytometry analysis using FACS
Calibur flow cytometer (Becton, Dickinson Systems, FACS
canto, USA) on MCF-7 cell line to determine the intracellular
uptake efficiency of the developed surface engineered MWCNT
formulations.20,27,34−36
The cellular uptake of free DOX and
DOX loaded MWCNT formulations using MCF-7 cell line was
performed through flow cytometry. The cell suspension was
incubated at 25 ± 2 °C for 4 h with intermittent mixing every
20 min. The 4 × 103
cells per well were seeded in a 12-well
plate and incubated for 24 h at 37 ± 0.5 °C with 5% CO2, and
then the medium in each well was replaced with 2 mL of
serum-free and antibiotic-free medium. Then various concen-
trations of MWCNT formulations (DOX solution, DOX/
MWCNTs, DOX/ox-MWCNTs, DOX/FA-PEG-MWCNTs,
and DOX/ES-PEG-MWCNTs) were incubated for 3 h.
Three hours post in vitro incubation, cells were washed three
times with ice-cold PBS, trypsinized (0.1%; w/v), pelletized via
centrifugation (1000g) to remove the trypsin, and finally
resuspended in PBS. Cells associated with DOX were measured
quantitatively (FACS Calibur flow cytometer; Becton, Dick-
inson Systems, FACS canto, USA) and qualitatively (fluo-
rescence microscope, Leica, Germany).
2.12. Cell Cycle Distribution Measurement. The DNA
content in the different cell cycle phases was determined by
flow cytometry for 24 h after treatment with the developed
MWCNT formulations.4,37−39
Briefly, 4 × 103
cells were seeded
and allowed to attach overnight at 37 ± 0.5 °C; the cultured
cells were treated with developed optimized nanotube
formulation (2 nM/mL concentration of drug) under CO2
atmosphere, and the incubated cells were harvested, washed,
and fixed using 70% cold ethanol overnight. Subsequently the
cells were trypsinized, washed again, fixed, and further
resuspended in hypotonic propidium iodide solution (PI; 50
μg/mL) containing ribonuclease A (RNase free, 100 μg/mL)
and incubated for 30 min at 37 °C in dark before measurement.
The distribution of cell cycle was determined with FACS
Calibur flow cytometer and analyzed using Cell Quest software
(Becton, Dickinson Systems, FACS canto, USA).
2.13. In Vivo Studies. 2.13.1. Animals and Dosing. The
Balb/c mice of either sex (20−25 g) were used for in vivo
studies, as mice present a more sensitive model for in vivo
evaluations. The experimental design was duly approved by the
Committee for the Purpose of Control and Supervision of
Experiments on Animals (CPCSEA) [Registration No. 379/
01/ab/CPCSEA/02] of Dr. H. S. Gour Vishwavidyalaya, Sagar-
470003 India. The Balb/c mice of uniform weight (20−25 g)
were housed in ventilated plastic cages with access to water ad
libitum. The mice were acclimatized at 25 ± 2 °C by
maintaining the relative humidity (RH) 55−60% under natural
light/dark condition prior to studies, avoiding any kind of stress
on Balb/c mice.4,16,40−43
2.13.2. Antitumor Targeting Efficacy Studies. The present
antitumor targeting efficacy study was performed on tumor
bearing Balb/c mice employing tumor growth inhibition study
and Kaplan−Meier survival curve analysis. The tumor was
developed on Balb/c mice using the well-known right flank
method4
by injecting serum-free cultured MCF-7 cells in the
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
633
5. right hind leg of the mice. The development of tumor was
regularly monitored by palpating the injected area with index
finger and thumb. When the tumor grew to approximately 100
mm3
in size, mice were subjected to in vivo studies and Balb/c
mice were accommodated in a pathogen-free laboratory
environment.20,42,44
The sterilized free DOX, DOX/
MWCNT, DOX/ox-MWCNT, DOX/PEG-MWCNT, DOX/
FA-PEG-MWCNT, and DOX/ES-PEG-MWCNT formulations
(equivalent dose = 5.0 mg/kg body weight) were intravenously
administered into the mice through the tail vein route. The size
of the tumor was measured using an electronic digital Vernier
caliper and calculated using the formula =1/2 × length ×
width2
. The median survival time was also recorded, and the
study was terminated 45 days post treatment.
2.13.3. Pharmacokinetic and Biodistribution Studies after
Intravenous Administration. The pharmacokinetic and bio-
distribution studies were performed on Balb/c mice after
intravenous administration of the free DOX and DOX loaded
MWCNT formulations (DOX/MWCNTs, DOX/ox-
MWCNTs, DOX/ES-PEG-MWCNTs, DOX/FA-PEG-
MWCNTs) at equivalent dose 5.0 mg/kg body weight dose.
The blood was collected in to the Hi-Anticlot blood collecting
vials (HiMedia, Mumbai, India) through retro-orbital plexus of
the animal’s eyes under mild anesthetic condition at the
different time points. The collected blood was centrifuged after
addition of 100 μL of trichloroacetic acid (TCA) in methanol
(10% w/v) to separate RBCs. Supernatant was collected,
vortexed, and ultracentrifuged (Z36HK, HERMLE LaborTch-
nik GmbH, Germany), and drug concentration was determined
using the high performance liquid chromatography (HPLC)
method. The pharmacokinetic parameters such as peak plasma
concentration (Cmax), the area under the curve (AUC0−t), area
under the first moment curve (AUMC), mean residence time
(MRT), half-life (t1/2), and half value duration (HVD) were
also calculated.4,16,18,45
The in vivo biodistribution study was also performed on
tumor bearing Balb/c mice after administration of the same
sterilized formulations. At 1, 6, 12, and 24 h time points mice
were carefully sacrificed by the decapitation method. The
different organs were separated out, washed with Ringer’s
solution for removal of any adhered debris, dried with tissue
paper, weighed, and stored frozen until used. Weighed tissues
samples were immediately homogenized (York Scientific
Instrument, New Delhi, India), vortexed, and ultracentrifuged
at 3000 rpm for 15 min (Z36HK, HERMLE LaborTchnik
GmbH, Germany). The obtained clear supernatant was
collected in HPLC vials and loaded onto the HPLC system
to determine the concentration of DOX (Shimadzu, C18,
Japan) using a mobile phase consisting of buffer pH 4.0/
acetonitrile/methanol (60:24:16; v/v/v) with 1.2 mL/min flow
rate at 102/101 bar.41,46−49
2.14. Statistical Analysis. The obtained data from the
studies were presented as mean ± standard deviation (n = 3),
and statistical analysis was performed using GraphPad InStat
software (Version 6.00, Graph Pad Software, San Diego,
California, USA) by one-way analysis of variance (ANOVA)
followed by Tukey−Kramer multiple comparisons test. The
comparison of the Kaplan−Meier survival analysis curve was
performed using the Log-rank (Mantel−Cox) test (conserva-
tive).The pharmacokinetic data analysis of the plasma
concentration time profile was conducted using the Kinetica
5.0 software (Thermo Scientific, USA), followed by non-
compartmental analysis. A probability p ≤ 0.05 was considered
significant while p ≤ 0.001 was considered as extremely
significant.
3. RESULTS AND DISCUSSION
The surface engineered smart, multifunctional carbon nano-
tubes appear to be useful in cancer chemotherapy as drug
delivery systems, owing to their unique physicochemical
properties and being continually explored in controlled and
targeted drug delivery. As-synthesized pristine MWCNTs were
procured and purified using different purification approaches
rendering them suitable for further studies. The presence of
impurities in pristine CNTs restricts their clinical application;
thus emerges functionalization that renders them more
biocompatible, safe, and effective for drug delivery. Function-
alization is a well-known approach for surface alteration of
CNTs. The f-MWCNTs used in the present investigation were
prepared after proper functionalization and conjugation of
targeting moieties, devoid of fluorescent dye, for cellular
trafficking because doxorubicin has red-autofluorescence.
The FTIR spectrum of procured unmodified (pristine)
MWCNTs depicts absorption peaks at 1626 and 2400.24 cm−1
.
The characteristic peak at 1626 cm−1
suggests the presence of
carbon residue on the CNT surface, while a clear single
characteristic peak at 2400.24 cm−1
is ascribed to the stretching
of the carbon nanotube backbone. The oxidized MWCNTs
shows characteristic peaks approximately at 1637.4 and 3425.6
cm−1
attributable to asymmetrical stretching of CO
stretching vibration mode and O−H stretching vibration,
respectively.4
The FTIR spectrum of the FA-PEG-MWCNTs showed
characteristic peaks at 1025.0, 3438.6, 2920.0, 1650.0, 1435.2,
and 1320.5 cm−1
. The peaks at 1650.0 and 1435.2 cm−1
of NH2
stretching and O−H deformation of phenyl skeleton and a
strong clear sharp characteristic peak observed at 1025.0 cm−1
of C−O stretching of ether linkage suggest the attachment of
FA-PEG to MWCNTs (Figure 1 A).
The estradiol conjugated with surface engineered MWCNTs
shows the characteristic peaks in the range of 1500−1655 cm−1
of −CO anhydride and amide bonding of estradiol
conjugated MWCNTs. A strong and sharp characteristic peak
Figure 1. FTIR spectra of (A) FA-PEG-MWCNTs and (B) ES-PEG-
MWCNTs.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
634
6. was found at 1020.04 cm−1
of C−O stretch of ether linkage due
to the presence of polyether backbone of PEG. The
characteristic peak at 1650.94 cm−1
of C−O stretching of
amide bond formation clearly indicates confirmation of
conjugation of estrone to MWCNTs (Figure 1 B).
The 1
H NMR spectra of the FA-PEG-MWCNTs and ES-
PEG-MWCNTs are shown in Figures 2A and 2B. The
characteristic signal of the pteridine ring proton and aromatic
protons of the p-aminobenzoic acid (PABA) of FA was clearly
present in the case of FA-PEG-MWCNTs (Figure 2 A).
Similarly, ES-PEG-MWCNTs represent the protons character-
istic of the phenyl ring of the steroidal moiety showing
chemical shifts as presented in the NMR spectrum (Figure 2
B).
Raman spectroscopy used for further characterization of the
developed MWCNT conjugates provides information on
hybridization state and defect site chemistry. It also gives
information on changes in electronic structure upon anchoring
of different chemical functional moieties. The MWCNTs show
the disorder related to D mode (approximately at 1330−1360
cm−1
) and high-energy mode known as tangential G mode
(approximately at 1500−1600 cm−1
).4
Raman spectra of ox-MWCNTs, FA-PEG-MWCNTs, and
ES-PEG-MWCNTs are shown in Figures 3A, 3B, and 3C. The
Raman spectrum of ox-MWCNTs shows the Raman shifts at
1584.73 and 1352.0 cm−1
, which correspond to the G band
(graphite-like mode) and D band (disorder-induced band),
respectively (Figure 3 A). The Raman spectrum of the FA-
PEG-MWCNTs shows the G band around 1565 cm−1
and D
band around 1310 cm−1
(Figure 3 B). The Raman spectrum of
the ES-PEG-MWCNTs shows the G band around 1580 cm−1
and D band around 1320 cm−1
(Figure 3 C). The shifting of G
and D band intensity toward higher intensity in the case of FA-
PEG-MWCNTs and ES-PEG-MWCNTs is mainly due to
increase in the extent of conjugation of FA/ES-PEG- with
functionalized MWCNTs, which would increase the single
bond characteristics in the functionalized systems.
Figure 2. NMR spectra of (A) FA-PEG-MWCNTs and (B) ES-PEG-MWCNTs.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
635
7. The transmission electron microscopy (TEM) clearly
revealed that the developed formulations were in nanometric
size range, even after conjugation.
The particle size and polydispersity index (PI) of the DOX/
MWCNTs, DOX/ox-MWCNTs, DOX/FA-PEG-MWCNTs,
and DOX/ES-PEG-MWCNTs were found to be 350.02 ±
5.24, 230.12 ± 6.56, 242.28 ± 5.85, and 240.26 ± 4.50 and 0.22
± 0.012, 0.32 ± 0.023, 0.55 ± 0.024, and 0.85 ± 0.034,
respectively. The loading efficiency of DOX/MWCNTs, DOX/
ox-MWCNTs, DOX/FA-PEG-MWCNTs, and DOX/ES-PEG-
MWCNTs was calculated to be 92.50 ± 2.62, 93.25 ± 3.52,
96.50 ± 2.52, and 96.80 ± 3.44, respectively, and determined
by absorption peak at 480.2 nm. A significant improvement in
the loading efficiency was observed in the case of ligand
conjugated MWCNTs through various interaction mechanisms
(such as π−π stacking, hydrogen bonding, and hydrophobic
interactions) owing to the aromatic structure of the
doxorubicin. Also large π-conjugated structures of the nano-
tubes can form π−π stacking interaction with the quinine part
of the DOX. One more possible reason is that cationically
charged DOX molecule could easily be adsorbed at lower
potential of ES-/FA-PEG-MWCNTs than pristine and ox-
MWCNTs via electrostatic interaction as well as π−π stacking
interaction that plays an important role with respect to DOX
loading.2,4,15
Huang et al. reported approximately 91% of DOX
loading efficiency in surface engineered SWCNTs.15
Similarly,
the high surface area and conjugation chemistry of MWCNTs
have been suggested to provide strong π−π stacking interaction
between CNTs and drug moieties.25
According to Niu et al.
DOX tends to strongly interact with side-walls of SWCNTs
through π−π stacking and hydrophobic interactions owing to
their aromatic nature.10
The DOX released from known amounts of DOX/FA-PEG-
MWCNTs, DOX/ES-PEG-MWCNTs, DOX/PEG-MWCNTs,
DOX/ox-MWCNTs, and DOX/MWCNTs was determined
separately in PBS (pH 7.4) and sodium acetate buffer solution
(pH 5.3) up to 200 h. The obtained release pattern exhibited a
nonlinear profile characterized by relatively faster initial release
followed by sustained and slower release at later periods in both
DOX/FA-PEG-MWCNT and DOX/ES-PEG-MWCNT for-
Figure 3. Raman spectra of (A) ox-MWCNTs, (B) ES-PEG-MWCNTs, and (C) FA-PEG-MWCNTs.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
636
8. mulations (Figure 4). Moreover DOX/ox-MWCNTs and
DOX/MWCNTs show faster release of DOX in both media.
The release of DOX from the MWCNT formulation mainly
depends on the solubility and pH of the media as well as the
interaction and cleavage of bonding; an appreciable DOX
release could be observed in an acidic pH solution, suggesting
pH-dependent release. It is clearly observed that pH-dependent
DOX release is beneficial in targeted drug delivery to cancerous
cells. However, the DOX molecules stacked on the surface
engineered MWCNT formulations are very stable in a neutral
solution (pH 7.4) at 37 °C. This pH-triggered DOX release
may be caused by a larger degree of protonation of the carboxyl
(−COOH) and amino (−NH2) groups on DOX at lower pH,
which weakens the interaction between DOX and MWCNTs.
At low pH, the hydrophilicity of DOX increases due to the
protonation of the NH2 groups native to its structure. The
increased hydrophilicity aids in overcoming the interaction
(π−π) among the DOX and the f-MWCNTs while facilitating
its detachment from the nanotubes4,14,15,51
Thus, the order of
release from MWCNT formulations at all pH ranges is as
follows:
Zhang and co-workers reported pH-triggered drug release
response from the modified nanotubes under normal
physiological conditions and release at reduced pH, typical of
microenvironments of intracellular lysosomes or endosomes
and cancerous tissue.14
Our in vitro release data of DOX are in
line with the previous reports.4,13−15,28
The MTT assay was performed to determine the cancer
targeting propensity of the DOX loaded nanotube formulations
at 0.001, 0.01, 1, 10, and 100 μM concentration for 24 and 48 h
treatment. The higher anticancer activity was achieved with
targeting ligand anchored MWCNTs most probably due to the
interaction of activated overexpressed estrone and folate
receptors on the cell surface hence higher targeting ligand−
receptor interaction affinity leading to apoptosis by intercalat-
ing DOX (anthracycline antibiotic) with DNA (Figure 5).
Figure 4. In vitro cumulative release behavior of DOX from developed carbon nanotube formulations at different pH conditions. Values represented
as mean ± SD (n = 3).
Figure 5. Percent cell viability of MCF-7 cells after treatment with free DOX, DOX/MWCNTs, DOX/ox-MWCNTs, DOX/PEG-MWCNTs,
DOX/FA-PEG-MWCNTs, and DOX/ES-PEG-MWCNTs at (A) 24 and (B) 48 h (n = 3).
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
637
9. However, the nontargeted (DOX/MWCNTs and DOX/ox-
MWCNTs) and PEGylated MWCNTs (DOX/PEG-
MWCNTs) showed lesser cytotoxicity owing to low internal-
ization in cancerous cells. The obtained results of cytotoxicity
(MTT) assay are in good agreement with the previous
published reports.14,27,33
Flow cytometric analysis was used to determine the cellular
uptake of the DOX loaded MWCNT formulations by MCF-7
cells. The cellular uptake efficiency was performed on MCF-7
cells after 3 h treatment with the different MWCNT
formulations (free DOX, DOX/MWCNTs, DOX/ox-
MWCNTs, DOX/PEG-MWCNTs, DOX/FA-PEG-MWCNTs,
and DOX/ES-PEG-MWCNTs) and is shown in Figures 6 and
7. The fluorescence intensity of DOX/ES-PEG-MWCNTs,
DOX/FA-PEG-MWCNTs, DOX/PEG-MWCNTs, DOX/ox-
MWCNTs, DOX/MWCNTs, and free DOX was found to be
78.65, 78.12, 66.22, 62.46, 60.25, and 58.15%, respectively. The
higher red fluorescence intensity was achieved in the case of
targeting ligand-anchored MWCNT formulations compared to
other formulations and control group. It is well reported that
the DOX has red-autofluorescence intensity. In line with the
cytotoxicity assay, cell uptake study also showed higher cellular
uptake of the targeting ligand anchored nanotube formulations
possibly due to the targeting ligand−receptor interactions
following receptor-mediated endocytosis and tiny nanoneedle
specific mechanism and higher drug release. In spite of the high
chemotherapeutic efficacy of DOX, clinical use is restricted due
to its dose-limiting cardiotoxicity and renal and hepatic toxicity.
The overall high cellular uptake efficiency was ranked in the
following order: DOX/ES-PEG-MWCNTs > DOX/FA-PEG-
MWCNTs > DOX/PEG-MWCNTs > DOX/ox-MWCNTs >
DOX/MWCNTs > free DOX > control.
The DNA cell cycle distribution study was performed to
investigate the phases in which the developed nanotube
formulations arrest the cancerous cells. The cell cycle analysis
could be recognized by the four distinct phases in a
proliferating cell population: G1, S, G2, and M phase.50
The
DOX/ES-PEG-MWCNTs showed 78.64%, 13.52%, and
11.22% cell arrest in G1, G2, and S phase, respectively.
However, DOX/FA-PEG-MWCNTs showed 76.97%, 12.17%,
and 10.86% cell arrest in G1, G2, and S phase, respectively.
Thus, we conclude that the doxorubicin loaded MWCNT
formulations were more efficient at attacking and killing the
cancerous cells in the G1 phase, i.e., DNA synthesis by
accumulation into nucleus. As it is well reported that the
doxorubicin interacts with DNA by intercalation, thus the
functions of DNA are affected and it is believed that the
Figure 6. Fluorescent images of breast cancer MCF-7 cells of (A) control and after treatment with (B) free DOX, (C) DOX/MWCNTs, (D)DOX/
PEG-MWCNTs, (E) DOX/ox-MWCNTs, (F) DOX/FA-PEG-MWCNTs, and (G) DOX/ES-PEG-MWCNTs (20 μM concentration).
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
638
10. scission of DNA is mediated by binding of DOX to DNA and
topoisomerase II enzyme.4
The pharmacokinetic parameters of DOX, DOX/ox-
MWCNTs, DOX/MWCNTs, DOX/PEG-MWCNTs, DOX/
Figure 7. Quantitative cell uptake in breast cancer MCF-7 cells of (A) control and after treatment with (B) free DOX, (C) DOX/MWCNTs,
(D)DOX/PEG-MWCNTs, (E) DOX/ox-MWCNTs, (F) DOX/FA-PEG-MWCNTs, and (G) DOX/ES-PEG-MWCNTs (20 μM concentration).
Table 1. Pharmacokinetic Parameters of Free DOX, DOX/MWCNT, DOX/ox-MWCNT, DOX/PEG-MWCNT, DOX/FA-PEG-
MWCNT, and DOX/ES-PEG-MWCNT Formulationsa
pharmacokinetic
parameters HVD (h)
AUC0−t (μg/mL·
h)
AUC0−∞ (μg/
mL·h)
AUMC0−t (μg/
mL·h2
)
AUMC0−∞ (μg/
mL·h2
) t1/2 (h) MRT (h)
free DOX 0.3564 ± 0.04 9.3066 ± 0.08 9.3292 ± 0.22 21.6860 ± 0.26 22.0079 ± 0.22 1.5648 ± 0.01 2.3590 ± 0.01
DOX/MWCNTs 0.8329 ± 0.03 22.3127 ± 1.20 22.9233 ± 0.42 131.0810 ± 4.66 149.8770 ± 3.86 4.7022 ± 0.02 6.5381 ± 0.02
DOX/ox-
MWCNTs
1.5208 ± 0.02 26.2936 ± 1.60 26.4129 ± 0.62 182.6100 ± 3.65 189.7500 ± 5.40 8.2596 ± 0.20 7.18397 ± 0.04
DOX/PEG-
MWCNTs
0.9319 ± 0.02 27.3680 ± 6.68 28.5475 ± 7.88 265.1670 ± 8.26 295.996 ± 6.64. 8.5706 ± 0.24 10.3685 ± 0.02
DOX/FA-PEG-
MWCNTs
0.9318 ± 0.01 28.3430 ± 0.98 30.4799 ± 1.36 305.4730 ± 4.82 446.0940 ± 6.50 12.3431 ± 0.12 14.6357 ± 0.12
DOX/ES-PEG-
MWCNTs
1.05418 ± 0.03 38.6518 ± 0.68 42.2180 ± 2.02 453.7930 ± 5.65 704.4600 ± 5.24 15.4495 ± 0.34 16.6863 ± 0.11
a
Values represented as mean ± SD (n = 3). Abbreviations: Cmax = peak plasma concentration; Tmax = time taken to reach Cmax; t1/2 = elimination
half-life; MRT = mean residence time; AUC0−∞ = area under plasma drug concentration over time curve; HVD = half value duration.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
639
11. FA-PEG-MWCNTs, and DOX/ES-PEG-MWCNTs were in-
vestigated in the blood samples using the HPLC technique
(Shimadzu, C18, Japan) after single iv administration in Balb/c
mice (Table 1). The AUC0−∞ of DOX/ES-PEG-MWCNTs
and DOX/FA-PEG-MWCNTs was 4.5-, 3.0-, and 1.8-, 1.2-fold
higher compared to free DOX and DOX/MWCNTs,
respectively. The AUMC0−∞ of DOX/ES-PEG-MWCNTs
was 32-fold while MRT was found to be 7.07-fold higher
compared to free DOX.
The average half-life (t1/2) of DOX/ES-PEG-MWCNTs
(15.4495 h) was 1.25, 1.80, 1.87, 3.28, and 9.87 times compared
to DOX/FA-PEG-MWCNTs, DOX/PEG-MWCNTs, DOX/
ox-MWCNTs, DOX/MWCNTs, and free DOX, respectively.
However, MRT values of DOX/ES-PEG-MWCNTs were 1.14,
1.60, 2.32, 2.55, and 7.07 times compared to DOX/FA-PEG-
MWCNTs, DOX/PEG-MWCNTs, DOX/ox-MWCNTs,
DOX/MWCNTs, and free DOX, respectively (Table 1). The
pharmacokinetic analysis results ascribed to the improved
biocompatibility and increased pharmacokinetic of highly
functionalized MWCNTs allow longer residence time inside
the animal body and impart the stealth characteristic.
Liu et al. reported long-term fate of PEG functionalized
SWCNTs after intravenous administration in animals and
found longest blood circulation up to 1 day and nearly
complete clearance of SWCNTs from the main organs
approximately in 2 months. The intrinsic stability and structural
flexibility of surface engineered CNTs may enhance the
circulation time as well as the bioavailability of drug
molecules.13,16
In vivo biodistribution studies were performed on tumor
bearing Balb/c mice after iv administration of the developed
nanotube formulations, and highest DOX level was found in
tumor, liver, and kidney in 24 h in the case of DOX/ES-PEG-
MWCNTs. Both DOX/FA-PEG-MWCNT and DOX/ES-
PEG-MWCNT formulations showed prolonged systemic
circulation in blood after single iv administration, and level of
DOX recovered per organ is shown in Figure 8. The amount of
DOX contents was found to be higher and accumulated
significantly more in tumor tissue for ES-PEG and FA-PEG-
MWCNTs compared to that of free DOX at all time points
owing to the presence of targeting ligand and PEGylation. The
acute cardiotoxicity is the main hurdle associated with
doxorubicin chemotherapy. Thus, the concentration of DOX
of the ligand anchored MWCNTs in the heart tissue was
significantly lower than other nanotube formulations and
efficiently delivered DOX at the target site through receptor-
mediated endocytosis or tiny nanoneedle mechanisms. Higher
amount of drug was delivered and accumulated at target sites
by developed DOX/ES-PEG-MWCNTs formulations enhanc-
ing the therapeutic index with minimal toxicity to healthy/
normal tissues like heart.
Antitumor activity of the different MWCNT formulations
was evaluated in tumor bearing Balb/c model after single iv
administration (5 mg/kg body weight). The DOX/ES-PEG-
MWCNT, DOX/FA-PEG-MWCNT, DOX/PEG-MWCNT,
DOX/ox-MWCNT, and free DOX formulations significantly
suppressed tumor growth compared to control group.
However, DOX/ES-PEG-MWCNT and DOX/FA-PEG-
MWCNT formulations showed higher tumor growth suppres-
sion than other formulations and free drug solution (Figure 9
A). The high antitumor activity of the FA- and ES-PEG-
conjugated MWCNTs can be attributed to its higher
accumulation in cancer cells through receptor-mediated uptake.
These antitumor activity results indicated that the PEGylation
of CNTs increases the overall tumor targeting efficiency of the
drug loaded ligand anchored MWCNT formulations.
The Kaplan−Meier survival curve analysis was used to
measure the fraction of the treated mice that survived over a
period of time. It is the simplest way of computing the survival
over time. The time starting from a defined point to the
occurrence of a given event, for example death, is called survival
Figure 8. Biodistribution patterns of free DOX, DOX/MWCNT, DOX/ox-MWCNT, DOX/PEG-MWCNT, DOX/ES-MWCNT, and DOX/FA-
PEG-MWCNT formulations in different tissues. Values represented as mean ± SD (n = 3).
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
640
12. time, and the analysis of group data is called survival
analysis.2,4,42
Survival periods were plotted between percent survival and
days elapsed to assess the effectiveness of developed MWCNT
formulations. Survival curves show, for each time plotted on the
x-axis, the portion of all individuals surviving at that time and
regularly monitored in the separate group up to 45 days. The
Kaplan−Meier survival curves suggested that the median
survival time for tumor bearing mice treated with DOX/ES-
PEG-MWCNTs (43 days) was extended compared to DOX/
FA-PEG-MWCNs (42 days), DOX/PEG-MWCNTs (33 days),
DOX/ox-MWCNTs (24 days), DOX/MWCNTs (23 days),
free DOX (18 days), and control group (12 days). The DOX/
ES-PEG-MWCNTs has also shown significantly longer survival
span (43 days) than DOX/FA-PEG-MWCNs (42 days), DOX/
PEG-MWCNTs (33 days), free DOX (18 days), and control
group (12 days) as shown in Figure 9B. Our antitumor
targeting activity results are in good agreement with the
previously published reports.2,4,42
4. CONCLUSION
At present the functionalized MWCNTs are the most widely
explored new generation targeted drug delivery system. The
cancer targeting potential of the different targeting chemical
moieties, i.e., estrone (ES) and folic acid (FA) anchored
MWCNTs, has been validated in the present investigation. In
this debut attempt, we have compared and explored the one-
platform comparative studies utilizing two targeting ligand
anchored surface engineered MWCNTs employing doxorubicin
(anthracycline antibiotic; anticancer agent) on MCF-7 cells.
The ligand anchored MWCNT formulations exhibit higher
loading efficiency, anticancer activity, and improved biocompat-
ibility profile along with increased pharmacokinetic parameters
compared to free drug solution. From the findings we conclude
that the overall pharmaceutical cancer targeting efficacy of
MWCNTs formulations utilizing MCF-7 cells ranked in the
following order: DOX/ES-PEG-MWCNTs > DOX/FA-PEG-
MWCNTs > DOX/PEG-MWCNTs > DOX/ox-MWCNTs >
DOX/MWCNTs > free DOX > control. Thus, estrone
anchored MWCNTs show superior targetability compared to
FA-anchored, oxidized (ox), plain MWCNTs, and free DOX
solution. In the future we wish to explore the various other drug
loaded targeting ligand anchored CNTs in the search of a safer
and more effective nanomedicine.
■ AUTHOR INFORMATION
Corresponding Author
*Tel/fax: + 91-7582-265055. E-mail: jnarendr@yahoo.co.in.
Notes
The authors declare no competing financial interest.
■ ACKNOWLEDGMENTS
One of the authors (N.K.M.) is thankful to University Grants
Commission (UGC), New Delhi, for providing the Senior
Research Fellowship during the tenure of the studies. The
authors also acknowledge Department of Physics, Dr. H. S.
Gour University, Sagar, India, for Raman spectroscopy; All
India Institute of Medicine and Sciences (AIIMS), New Delhi,
India (TEM); Indian Institute of Technology (IIT), Indore
(AFM), India; Central Instruments Facilities (CIF), National
Institute of Pharmaceutical Education and Research (NIPER),
Mohali, Chandigarh, India; Central Drug Research Institute
(CDRI), Lucknow; Diya Laboratory, Mumbai, India. The
authors are also thankful to National Centre for Cell Sciences
(NCCS), Pune, India, for providing the MCF-7 cell lines.
■ REFERENCES
(1) Mehra, N. K.; Jain, N. K. Functionalized Carbon Nanotubes and
Their Drug Delivery Applications; Bhoop, B. S., Ed.; Studium Press,
LLC: London, 2014; Vol. 4, pp 327−369.
(2) Mehra, N. K.; Jain, N. K. Development, characterization and
cancer targeting potential of surface engineered carbon nanotubes. J.
Drug Targeting 2013, 21 (8), 745−758.
(3) Iijima, S. Helical microtubules of graphitic carbon. Nature 1991,
354, 56−58.
(4) Mehra, N. K.; Verma, A. K.; Mishra, P. R.; Jain, N. K. The cancer
targeting potential of D-α-tocopheryl polyethylene glycol 1000
succinate tethered multi walled carbon nanotubes. Biomaterials 2014,
35, 4573−4588.
(5) Jain, K.; Mehra, N. K.; Jain, N. K. Potential and emerging trends
in nanopharmacology. Curr. Opin. Pharmacol. 2014, 15, 97−106.
(6) Ali-Boucetta, H.; Kostarelos, K. Pharmacology of carbon
nanotubes: Toxicokinetics, excretion and tissue accumulation. Adv.
Drug Delivery Rev. 2013, 65, 2111−2119.
(7) Fan, J.; Zeng, F.; Xu, J.; Wu, S. Targeted anti-cancer prodrug
based on carbon nanotube with photodynamic therapeutic effect and
pH-triggered drug release. J. Nanopart. Res. 2013, DOI: 10.1007/
s11051-013-1911-z.
(8) Jain, A. K.; Mehra, N. K.; Lodhi, N.; Dubey, V.; Mishra, D.; Jain,
N. K. Carbohydrate-conjugated multiwalled carbon nanotubes:
development and characterization. Nanomedicine 2009, 5 (4), 432−
442.
(9) Lacerda, L.; Russier, J.; Pastorin, G.; Herrero, M. A.; Venturelli,
E.; Dumortier, H.; Al-Jamal, K. T.; Prato, M.; Kostarelos, K.; Bianco,
A. Translocation mechanisms of chemically functionalized carbon
nanotubes across plasma membranes. Biomaterials 2012, 33, 3334−
3343.
Figure 9. (A) Tumor regression analysis and (B) Kaplan−Meier
survival curves of MCF-7 bearing Balb/c mice analyzed by Log-rank
(Mantel−Cox) after intravenous administration of free DOX, DOX/
MWCNT, DOX/PEG-MWCNT, DOX/ox-MWCNT, DOX/FA-
PEG-MWCNT, and DOX/ES-PEG-MWCNT formulations at 5.0
mg/kg body weight dose, where *p ≤ 0.05, **p ≤ 0.01, and *** p ≤
0.001.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
641
13. (10) Niu, L.; Meng, L.; Lu, Q. Folate-conjugated PEG on single-
walled carbon nanotubes for targeting delivery of doxorubicin to
cancer cells. Macromol. Biosci. 2013, 13, 735−744.
(11) Fabbro, C.; Ali-Boucetta, H.; Ros, T. D.; Kostarelos, K.; Bianco,
A.; Prato, M. Targeting carbon nanotubes against cancer. Chem.
Coummun. 2012, 48, 3911−3926.
(12) Mehra, N. K.; Mishra, V.; Jain, N. K. A review of ligand tethered
surface engineered carbon nanotubes. Biomaterials 2014, 35 (4),
1267−1283.
(13) Liu, Z.; Sun, X.; Nakayama-Ratchford, N.; Dai, H. Supra-
molecular chemistry on water soluble carbon nanotubes for drug
loading and delivery. ACS Nano 2007, 1 (1), 50−56.
(14) Zhang, X.; Meng, L.; Lu, Q.; Fei, Z.; Dyson, P. J. Targeted
delivery and controlled release of doxorubicin to cancer cells using
modified single wall carbon nanotubes. Biomaterials 2009, 30, 6041−
6047.
(15) Huang, H.; Yuan, Q.; Shah, J. S.; Misra, R. D. K. A new family of
folate-decorated and carbon nanotubes-mediated drug delivery system:
synthesis and drug delivery response. Adv. Drug Delivery Rev. 2011, 63,
1332−1339.
(16) Liu, Z.; Chen, K.; Davis, C.; Sherlock, S.; Cao, Q.; Chen, X.;
Dai, H. Drug delivery with carbon nanotubes for in vivo cancer
treatment. Cancer Res. 2008, 68 (16), 6652−6660.
(17) Mody, N.; Tekade, R. K.; Mehra, N. K.; Chopdey, P.; Jain, N. K.
Dendrimer, liposomes, carbon nanotubes and PLGA nanoparticles:
one platform assessment of drug delivery potential. AAPS
PharmSciTechn 2014, 15 (2), 388−399.
(18) Singh, R.; Mehra, N. K.; Jain, V.; Jain, N. K. Folic acid
conjugated carbon nanotubes for gemcitabine HCL delivery. J. Drug
Targeting 2013, 21 (6), 581−592.
(19) Wu, W.; Wieckowski, S.; Pastorin, G.; Benincasa, M.; Klumpp,
C.; Briand, J. P. Targeted delivery of Amphotericin B to cells by using
functionalized carbon nanotubes. Angew. Chem., Int. Ed. 2005, 44,
6358−6362.
(20) Bhatnagar, I.; Venkatesan, J.; Kim, S.-K. Polymer functionalized
single walled carbon nanotubes mediated drug delivery of Gliotoxin in
cancer cells. J. Biomed. Nanotechnol. 2014, 10 (1), 120−130.
(21) Gupta, R.; Mehra, N. K.; Jain, N. K. Fucosylated multiwalled
carbon nanotubes for Kupffer cells targeting for the treatment of
cytokine-induced liver damage. Pharm. Res. 2013, 31 (2), 322−334.
(22) Wu, L.; Man, C.; Wang, H.; Lu, X.; Ma, Q.; Cai, Y.; Ma, W.
PEGylated multi-walled carbon nanotubes for encapsulation and
sustained release of oxaliplatin. Pharm. Res. 2013, 30, 412−423.
(23) Paliwal, S. R.; Paliwal, R.; Pal, H. C.; Saxena, A. K.; Sharma, P.
R.; Gupta, P. N.; Agrawal, G. P.; Vyas, S. P. Estrogen-anchored pH-
sensitive liposomes as nanomodule designed for site-specific delivery
of doxorubicin in breast cancer therapy. Mol. Pharmaceutics 2012, 9
(1), 176−186.
(24) Lodhi, N.; Mehra, N. K.; Jain, N. K. Development and
characterization of dexamethasone mesylate anchored on multi walled
carbon nanotubes. J. Drug Targeting 2013, 21 (1), 67−76.
(25) Lu, Y. J.; Wei, K. C.; Ma, C. C. M.; Yang, S. Y.; Chen, J. P. Dual
targeted delivery of doxorubicin to cancer cells using folate-conjugated
magnetic multi-walled carbon nanotubes. Colloids Surf., B 2012, 89, 1−
9.
(26) Mehra, N. K.; Mishra, V.; Jain, N. K. Receptor based therapeutic
targeting. Ther. Delivery 2013, 4 (3), 369−394.
(27) Das, M.; Singh, R. P.; Datir, S. R.; Jain, S. Intracellular drug
delivery and effective in vivo cancer therapy via estradiol-PEG-
appended multi walled carbon nanotubes. Mol. Pharmaceutics 2013, 10
(9), 3404−3416.
(28) Das, M.; Singh, R. P.; Datir, S. R.; Jain, S. Surface chemistry
dependent “switch” regulated the trafficking and therapeutic perform-
ance of drug-loaded carbon nanotubes. Bioconjugate Chem. 2013, 24,
626−639.
(29) Zalipsky, S.; Gilon, C.; Zalkha, A. Attachment of drugs to
polyethylene glycols. Eur. Polym. J. 1983, 19, 1177−1183.
(30) Rai, S.; Paliwal, R.; Vyas, S. P. Targeted delivery of doxorubicin
via estrone-appended liposomes. J. Drug Targeting 2008, 16 (6), 455−
463.
(31) Lee, R. J.; Low, P. S. Folate-mediated tumor cell targeting of
liposome entrapped doxorubicin in vitro. Biochim. Biophys. Acta 1995,
1233, 134−144.
(32) Kesharwani, P.; Tekade, R. K.; Jain, N. K. Formulation
development and in vitro−in vivo assessment of the fourth-generation
PPI dendrimer as a cancer-targeting vector. Nanomedicine 2014, 9
(15), 2291−2308 DOI: 10.2217/nnm.13.210.
(33) Lee, P. C.; Chiou, Y. C.; Wong, J. M.; Peng, C. L.; Shieh, M. J.
Targeting colorectal cancer cells with single-walled carbon nanotubes
conjugated to anticancer agent SN-38 and EGFR antibody.
Biomaterials 2013, 34, 8756−8765.
(34) Nima, Z. A.; Mahmood, M. W.; Karmakar, A.; Mustafa, T.;
Bourdo, S.; Xu, Y.; Biris, A. S. Single-walled carbon nanotubes as
specific targeting and Raman spectroscopic agents for detection and
discrimination of single human breast cancer cells. J. Biomed. Opt.
2013, 18 (5), 55003.
(35) Sacchetti, C.; Rapini, N.; Magrini, A.; Cirelli, E.; Bellucci, S.;
Matteri, M.; Rosato, N.; Bottini, N.; Bottini, M. In vivo targeting of
intracellular regulatory T cell using PEG-modified single-walled carbon
nanotubes. Bioconjugate Chem. 2013, 24, 852−858.
(36) Delogu, L. G.; Venturelli, E.; Manetti, R.; Pinna, G. A.; Carru,
C.; Madeddu, R.; Murgia, L.; Sgarrella, F.; Dumortier, H.; Bianco, A.
Ex vivo impact of functionalized carbon nanotubes on human immune
cells. Nanomedicine 2012, 7 (2), 231−243.
(37) Chen, J.; Li, S.; Shen, Q. Folic acid and cell-penetrating peptide
conjugated PLGA-PEG bifunctional nanoparticles for vincristine
sulfate delivery. Eur. J. Pharm. Sci. 2012, 47, 430−443.
(38) Han, Y.; Xu, J.; Li, Z.; Ren, G.; Yang, Z. In vitro toxicity of
multi-walled carbon nanotubes in C6 rat glioma cells. Neurotoxicology
2012, 33, 1128−1134.
(39) Kundu, P.; Mohanty, C.; Sahoo, S. K. Anti-glioma activity of
curcumin-loaded lipid nanoparticles and its enhanced bioavailability in
brain tissue for effective glioblastoma therapy. Acta Biomater. 2012, 8,
2670−2687.
(40) Mulvey, J. J.; Villa, C. H.; MCDevitt, M. R.; Escorcia, F. E.;
Casey, E.; Scheinberg, D. A. Self-assembly of carbon nanotubes and
antibodies on tumours for targeted amplified delivery. Nat. Nano-
technol. 2013, 8, 763−771.
(41) Lin, Z.; Xi, Z.; Huang, J. Biodistribution of single-walled carbon
nanotubes in rats. Toxicol. Res. 2014, DOI: 10.1039/C3TX50059D.
(42) Ren, J.; Shen, S.; Wang, D.; Xi, Z.; Guo, L.; Pang, Z.; Qian, Y.;
Sun, X.; Jiang, X. The targeted delivery of anticancer drugs to brain
glioma by PEGylated oxidized multi-walled carbon nanotubes
modified with angiopep-2. Biomaterials 2012, 33, 3324−3333.
(43) Ji, Z.; Lin, G.; Lu, Q.; Meng, L.; Shen, X.; Dong, L.; Fu, C.;
Zhang, X. Targeted therapy of SMMC-7721 liver cancer in vitro and in
vivo with carbon nanotubes based drug delivery systems. J. Colloid
Interface Sci. 2012, 365, 143−149.
(44) Muscella, A.; Vertugno, C.; Migoni, D.; Biagioni, F.; Fanizzi, F.
P.; Fornai, F.; De Pascali, S. A.; Marsigliante, S. Antitumor activity of
[Pt (O,O′-acac) (γ-acac) (DMS) in mouse xenograft model of breast
cancer. Cell Death Dis. 2014, 5, e1014.
(45) Cherukuri, P.; Gannon, C. J.; Leeuw, T. K.; Schmidt, H. K.;
Smalley, R. E.; Curley, S. A.; Weisman, R. B. Mammlian
pharmacokinetics of carbon nanotubes using intrinsic near-infrared
fluorescence. Proc. Natl. Acad. Sci. U.S.A. 2006, 103 (50), 18882−
18886.
(46) Al-Jamal, K. T.; Nunes, A.; Methven, L.; Ali-Boucetta, H.; Li, S.;
Toma, F. M.; Herrero, M. A.; Al-Jamal, W. T.; Eikelder, H. M. M.;
Foster, J.; Mather, S.; Prato, M.; Bianco, A.; Kostarelos, K. Degree of
chemical functionalization of carbon nanotubes determines tissue
distribution and excretion profile. Angew. Chem., Int. Ed. 2012, 51,
6389−6393.
(47) Bhirde, A.; Patel, V.; Gavard, J.; Zhang, G.; Sousa, A. A.;
Masedunskas, A.; Leapman, R. D.; Weigert, R.; Gutkind, J. S.; Rusling,
J. F. Targeted killing of cancer cells in vivo and in vitro with EGF-
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
642
14. directed carbon nanotubes-based drug delivery. ACS Nano 2009, 3
(2), 307−316.
(48) Campagnolo, L.; Massimiani, M.; Palmieri, G.; Bernardini, R.;
Sacchetti, C.; Bergamaschi, A. Biodistribution and toxicity of pegylated
single wall carbon nanotubes in pregnant mice. Part. Fibre Toxicol.
2013, DOI: 10.1186/1743-8977-10-21.
(49) Jain, S.; Thakare, V. S.; Das, M.; Godugu, C.; Jain, A. K.;
Mathur, R.; Chuttani, K.; Mishra, A. K. Toxicity of multi walled carbon
nanotubes with end defects critically depends on their functionaliza-
tion density. Chem. Res. Toxicol. 2011, 24 (11), 2028−2040.
(50) Nunez, R. DNA measurement and cell cycle analysis by flow
cytometry. Curr. Issues Mol. Biol. 2001, 3 (3), 67−70.
(51) Dinan, N. M.; Atyabi, F.; Rouini, M. R.; Amini, M.; Golbchifar,
A. K.; Dinarvand, R. Doxorubicin loaded folate-targeted carbon
nanotubes: preparation, cellular internalization, in vitro cytotoxicity
and disposition kinetic study in the isolated perfused rat liver. Mater.
Sci. Eng. C 2014, 39, 47−55.
Molecular Pharmaceutics Article
DOI: 10.1021/mp500720a
Mol. Pharmaceutics 2015, 12, 630−643
643