Nanomedicine may be defined as the monitoring, repair, construction and control of human biological systems at the molecular level, using engineered nanodevices and
The detection and controlled manipulation of human biological system at the molecular level via engineered nanodevices and/or nanostructures.
Nanomedicine is the science and technology of diagnosing, treating and preventing disease and traumatic injury, of relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body.
It is used for the diagnosis, prevention and treatment of disease and to gain to increased understanding of complex underlying dieses mechanism.
Nanomedicine is an interdisciplinary field of science, even simple project needs contributions from engineers, material chemists, biologists and end users, such as an orthopedic surgeon.
A mature nanomedicine will require the ability to build structures and devices with atomic precision, hence molecular nanotechnology and molecular manufacturing are key enabling technologies for nanomedicine.
Nanomedicine must catch up with the technology level of the human body to become really effective. The result will be the ability to analyze and repair the human body as we can repair a conventional machine today.
If the nano concept holds together, it could be the groundwork for a new industrial revolution.
Current Areas of Nanomedicine
Nanomedicine has a limited number of current applications.
Current research and development efforts are concentrated in
six primary categories:
Definition of Nanotechnology
According to National Nanotechnology Initiative (NNI),
nanotechnology is defined as:
“ Research and technology development at the atomic,
molecular and macromolecular levels in the length scale of
approximately 1 - 100nanometer range, to provide a
fundamental understanding of phenomena and materials at
the nanoscale and to create and use structures, devices and
systems that have novel properties and functions because of
their small and/or intermediate size.”
“ nano” indicates 10 -9
A nanometre is 10 -9 meter.
The size of selected nanotechnology materials is
estimated to be as follows:
Nanoparticles 1 – 100 nm
Fullerene (C60) 1 nm
Quantum Dot 8 nm
Dendrimer 10 nm
Materials found in nature are typically referenced to
have the following dimensions:
Atom 0.1 nm
DNA (width) 2 nm
Protein 5 – 50nm
Virus 5 – 100nm
Bacteria 1,000 – 10,000 nm
White Blood Cell 10,000 nm
Achievement And Future prospects for Nanomedicine:
1 st generation product (2000)
Dispersed and contact nanostructure
Product incorporating nanostructure
2 nd active nanostructure(2000-2005)
bio-active, health effect
Physico chemical active adaptive structure
3 rd Nanosystem(2005-2010)
Ex-:robotics, evolutionary biosystems
4 th Molecular nanosystems(2010-2020)
Ex-: molecular devices ‘by design’
Application of nanomedicine
1) Drug Delivery:
a) Drug Encapsulation
Materials that encapsulate drugs to protect them during transit in the body.
Nanoparticles in the 1 to 100nm size range instead of bigger micro particles, they have a larger surface area for the same volume, smaller pore size, improved solubility, and different structural properties.
This can improve both the diffusion and degradation characteristics of the encapsulation Material.
Nanoparticles encapsulation is also being investigated for the treatment of neurological disorders like Parkinson’s, Alzheimer’s diseases.
Ex:-Nanoscale silica and calcium phosphate.
b) Functional Drug Carriers
Nanomaterials that carry drugs to their destination sites and also have functional properties .
Certain nanostructures can be controlled to link with a drug, a targeting molecule, and an imaging agent, then attract specific cells and release their payload When required.
Some of the leading nanostructures being used for this purpose include fullerenes, dendrimers, and nanoshells.
C Sixty (fullerene) is developing fullerene-based drug delivery platforms which link fullerenes with antibodies and other targeting agents.
Several drug candidates using its fullerene platform technology in the areas of HIV/AIDS, neuro-degenerative disorders and cancer.
dendrimers to get genetic material or tumor-destroying therapies into a cell without triggering an immune response. This is due to the dendrimer`s small size and branched structure.
The nanoshell has a gold exterior layer which covers interior layers of silica and Drugs. It can release tumor- specific antibodies when infrared light is administered.
2) Drug Discovery :
Nano and micro technologies are part of the latest advanced solutions and new paradigms for decreasing the discovery and development times for new drugs, and potentially reducing the development costs.
High-throughput arrays and ultra-sensitive labeling and
detection technologies are being used to increase the speed and accuracy of identifying genes and genetic materials for drug discovery and development.
1) Tissue Repair and Replacement :
a) Implant Coatings
Nanotechnology brings a variety of new high surface area biocompatible nanomaterials and coatings to increase the adhesion, durability and lifespan of implants.
For example, nanopolymers such as polyvinyl alcohol (PVA) can be used to coat implantable devices that are in contact with blood (e.g. artificial hearts, vascular grafts, catheters) for dispersing clots or preventing their formation.
b) Tissue Regeneration Scaffolds
Nanostructures are being researched for the preparation and improvement of tissue regeneration scaffolds.
Ex:-PVA is also being investigated for the cornea by having
corneal epithelia cells seeded in a PVA hydro gel
structure. This polymer material can absorb more than
20% its weight in water while maintaining a distinct three
2) Structural Implant Materials:
a) Bone Repair
Nanotechnology brings a variety of new high surface area biocompatible nanomaterials that can be used for bone repair and cavity fillers.
Ex:- High strength nanoceramic materials, such as calcium
phosphate apatite (CPA) and hydroxyapatite (HAP)
b) Bioresorbable Materials
Bioresorbable polymers are currently being used in degradable medical applications such as sutures and orthopedic fixation devices.
Nanostructure implants are being designed to degrade at a rate that will slowly transfer load to a healing bone that it is supporting.
c) Smart Materials
Smart materials are a class of nanomaterials that respond to changes in the environment such as a drop in temperature or pH.
For example, applications could include a smart polymer that flexes with mechanical strength as an artificial muscle, or a hydro gel that dissolves according to body chemistry to more efficiently deliver drugs.
1) Assessment and Treatment Devices:
a) Implantable Sensors
Micro and nanosized sensors can make use of a wide range of technologies that most effectively detect a targeted chemical or physical property.
Use polyethylene glycol beads coated with fluorescent molecules to monitor diabetes blood sugar levels. The beads are injected under the skin and stay in the interstitial fluid. When glucose in the interstitial fluid drops to dangerous levels, glucose displaces the fluorescent molecules and creates a glow. This glow is seen on a tattoo placed on the arm.
b) Implantable Medical Devices
Implantable sensors can also work with a series of medical devices that administer treatment automatically if required.
Tiny implantable fluid injection systems can dispense drugs electrically on demand making use of microfluidic systems, miniature pumps, and reservoirs.
For Example Implantable sensors that monitor the heart’s activity level can also work with an implantable defribulator to regulate heartbeats.
2) Sensory Aids :
a) Retina Implants
The artificial retina uses a miniature video camera attached to a blind person’s eyeglasses to capture visual signals.
The signals are processed by a microcomputer worn on the belt and transmitted to an array of electrodes placed in the eye.
The array stimulates optical nerves, which then carry a signal to the brain.
b) Cochlear Implants
An implanted transducer is pressure-fitted onto the incus bone
in the inner ear. The transducer causes the bones to vibrate and
move the fluid in the inner ear, which stimulates the auditory
Cochlear Implants Surgical Aids : 1) Operating Tools a) Smart Instruments
Surgical tools such as scalpels, forceps, grippers, retractors and drills are being embedded with miniature sensors to provide real-time information and added functionality to aid surgeons.
Surgeons can be given continuous data on the force and performance of their instruments, the tissue type about to be cut (i.e. cartilage, bone, muscle, vascular, etc) and specific tissue properties, such as density, temperature, pressure, and electrical impulses.
b) Surgical Robotics
Instead of manipulating surgical instruments, surgeons use their thumbs and fingers to move joystick handles on a control console to maneuver two robot arms containing miniature instruments that are inserted into ports in the patient. The surgeon’s movements transform large motions on the remote controls into micro-movements on the robot arms to greatly improve mechanical precision and safety
A third robot arm holds a miniature camera, which is inserted through a small opening into the patient. The camera projects highly magnified 3-D images on a console to give a broad view of the interior surgical site.
(The daVinci Surgical Robotics System)
Ex:-UCI Medical Center’s da Vinci Surgical System is currently
approved for gall bladder,prostrate,colorectal,gynecological,
esophageal and gastric bypass procedures.
Diagnostic Tools :
1) Genetic Testing:
a) Ultra-sensitive Labeling and Detection Technologies
At Genicon, gold nanoparticle probes are being treated with chemicals that cling to target genetic materials and illuminate when the sample is exposed to light.
b) High Throughput Arrays and Multiple Analyses
By using nanomaterials as sensing particles, chips could be reduced in size. This would allow scientists to read thousands of molecules with the possibility of using cheaper equipment
Ex:-lab-on-a-chip, can integrate mixing, moving, incubation,
separation, detection and data processing in a small
b) Miniature Imaging Devices
Given Imaging has developed a pill containing a miniature video system.
When the pill is swallowed, it moves through the digestive system and takes pictures every few seconds.
The entire digestive system can be assessed for tumors, bleeding, and diseases in areas not accessible with colonoscopies and endoscopies.
a) Nanoparticle Probes
Nanoparticles with a magnetic core are attached to a cancer antibody that attracts cancer cells.
The nanoparticles are also linked with a dye which is highly visible on an MRI.
When these nanoprobes latch onto cancer cells they can be detected on the MRI. The cancer cells can then be destroyed by laser or low dosage killing agents that attack only the diseased cells.
Moving to Market Company Indication Phase Type of nanomaterial Product Insert Therapeutics Matastatic solid IND filed Cyclodextrin nanoparticle Cyclosertcamptothecin American Pharmaceutical Partners Lung cancer, breast cancer, others NDA filed Nanoparticle albumin Abraxane ImaRx Therapeutics Oncology Preclinical Branching block copolymer self- assembled Nanoparticulate formulation of Irinotecan metabolite MRX-952 Star pharma Topical microbicide for HIV phase2 Dendrimer VivaGel
Advanced Magnetics Tumor imaging NDA filed Iron oxide nanoparticle Combidex Introgen Metastatic lung cancer Phase 1 Liposome INGN-401 Nanosphere Diagnostics On market DNA Functionalized Gold nanoparticles Verigene platform Triton BioSystems Solid tumors Preclinical Polymer-coated iron oxide TNT AntiEpCAM
Medical Nanomaterials And Nanodevices:
One of the earliest therapeutically useful nanomedical devices 45, employing bulk micromachining to fabricate tiny cell-containing chambers within single crystalline silicon wafers.
The chambers interface with the surrounding biological environment through polycrystalline silicon filter membranes which are micromachined to present a high density of uniform Nanopores as small as 20 nanometers in diameter.
(Nanopores and DNA)
These pores are large enough to allow small molecules such as oxygen, glucose, and insulin to pass, but are small enough to impede the passage of much larger immune system molecules such as immunoglobulin and graft-borne virus particles.
2) Artificial Binding Sites and Molecular
Another early goal of nanomedicine is to study how biological molecular receptors work, and then to build artificial binding sites on a made-to-order basis to achieve specific medical results.
Molecular imprinting is an existing technique in which a cocktail of functionalized monomers interacts reversibly with a target molecule using only noncovalent forces. The complex is then cross-linked and polymerized in a casting procedure, leaving behind a polymer with recognition sites complementary to the target molecule in both shape and functionality.
Each such site constitutes an induced molecular “memory,” capable of selectively binding the target species.
3) Quantum dot:
These dots are tiny particles measuring only a few nanometers across, about the same size as a protein molecule or a short sequence of DNA.
They come in a nearly unlimited palette of sharply-defined colors which can be customized by changing particle size or composition.
Particles can be excited to ﬂuorescence with white light, can be linked to biomolecules to form long-lived sensitive probes to identify specific compounds up to a thousand times brighter than conventional dyes used in many biological tests, and can track biological events by simultaneously tagging each biological component (e.g., different proteins or DNA sequences) with nanodots of a specific color.
One nanometer buckyballs made from just a few dozen carbon atoms.
Nanoparticles such as C60 have many properties which make them attractive candidates for many therapies.
Low or negligible toxicity (metabolically inert)
High physiological stability
High radiation stability
Extremely small molecular size.
Nanoshells are extremely small beads of glass coated
They can be fashioned to absorb light of almost any
wavelength, but nanoshells that capture energy in the
near-infrared, which can easily penetrate several
centimeters of tissue.
A dendrimer molecule branches successively from inside to outside.
Its shape resembles what one would get by taking many sprigs from a tree and poking them into a foam ball so that they shot out in every direction.
That is, they have an enormous amount of internal surface area.
Dendrimers are globular molecules about the size of typical protein, but they do not come apart or unfold as easily as proteins do, because they are held together with stronger chemical bonds.
(Using Dendrimer Surfaces
to Bind Biological Molecules) (Dendrimers)
A numerous novel nanomedicine-related application are under development or nearing commercialization, the
process of converting basic research in nanomedicine into commercially viable products will be long and difficult.
Although realization of the full potential of nanomedicine may be years or decades away, recent advances in nanotechnology-related drug delivery, diagnosis, and drug development are beginning to change the landscape medicine.
New nanotechnologies may offer the only hope for systematic, affordable, and long term improvements to the health status of our population. This is because nano therapies could, in the long run, be much more economical, effective and safe and could greatly reduce the cost of or substantially eliminate current medical procedures.