harnesses biological processes and uses them for our own applications.A subset of nanotechnology: atom-level engineering and manufacturingusing biological precedents for guidance. It is also closely married tobiotechnology but adds the ability to design and modify the atomic-leveldetails of the objects created.
Bionanomaterials1) Biological materials utilized in nanotechnology - Proteins, enzymes, DNA, RNA, peptides Cross-linked enzymes used2) Synthetic nanomaterials utilized as catalyst – Univ. of Connecticut, in biomedical applications Storrs , 2007 - Polymers, porous silicon, carbon nanotubes Enzymes are used as oxidation catalysts Bone cell on porous siliconPorous silicon (PSi) Human cell on PSi – Univ. of Rochester, 2007
Bionanomachines are designed to atomicspecifications, they perform a well-definedthree-dimensional molecular task, and, in thebest applications, they contain mechanisms forindividual control embedded in their structure. viewing the “microscopic dynamics’ of what is occurring in the human body at a cellular level “is like observing human activity on Earth from an orbiting satellite,”
Nanochip− Currently available microprocessors use resolutions as small as 32 nm− Houses up to a billion transistors in a single chip− MEMS based nanochips have future capability of 2 nm cell leading to 1TB memory per chipNanoelectromechanical System(NEMS) Sensors− NEMS technology enables creation of ultra small and highly sensitive sensors for various applications− The NEMS force sensor shown in the figure is applicable in pathogenic bacteria detection
Designed to pick up specific biological signals usually by producing a digital electronic signal associated with a specific biological or chemical compound.It work by measuring sample interactions with a reactant as itforms in to a product. The reaction is picked up by a sensor thatconverts it to an electrical signal. The signal is then displayed/recordedon a computer monitor.
Nanomedicine is the application ofnanotechnology in medicine, including tocure diseases and repair damaged tissuessuch as bone, muscle, and nerveKey Goals for Nanomedicine− To develop cure for traditionally incurable diseases (e.g. cancer) through the utilization of nanotechnology− To provide more effective cure with fewer side effects by means of targeted drug delivery systems
• Genetics information storage and retrieval• Diagnostics, such as the identifi cation of disease• Detection of overall disease susceptibility, such asAlzheimer’s• Better classifi cation of diseases into different types andsubtypes• Tailor-made drug design based on chromosomaldifferences• Gene therapy (e.g., for cystic fi brosis)• Cell targeting (antibody development that zeroes in onspecific cells)
Nanotechnology offerstools and techniques formore effective detection,diagnosis and treatment of The microfluidic channel with nanowirediseases sensor can detect the presence of altered genes associated with cancer – J. Heath, Cali. Insti. of TechnologyDetection and Diagnosis• Lab on chips help detection and diagnosis of diseases more efficiently• Nanowire and cantilever lab on The nanoscale cantilever detects the chips help in early detection of presence and concentration of various cancer biomarkers molecular expressions of a cancer cell – A. Majumdar, Univ. of Cal. at Berkeley
Lab on Chip− A lab on chip integrates one or more laboratory operation on a single chip− Provides fast result and easy operation− Applications: Biochemical analysis (DNA/protein/cell analysis) and bio-defense Lab on chip gene analysis device – IBN Singapore, 2008 Microfluidics is the study of using nanoscale liquid-filled channels to move cells to different areas on a base for various different types of study.
Drug Delivery SystemsImpact of nanotechnology on drug delivery systems:− Targeted drug delivery− Improved delivery of poorly water soluble drugs− Co-delivery of two or more drugs− Imaging of drug delivery sites using imaging modalities Currently, most anti-cancer drugs can affect healthy and cancerous tissue. Thats why the side effects of chemotherapy can be so dramatic and difficult to endure. But if doctors could create a device that could target specific cancer cells, they could use medicine in such a precise way that only the cancer would be affected. As a result, patients would experience fewer side effects.
• Targeted drug delivery− Nanoparticles containing drugs are coated with targeting agents (e.g. conjugated antibodies)− The nanoparticles circulate through the Targeted drug delivery – blood vessels and reach Targeted drug delivery using a multicomponent nanoparticle the target cells containing therapeutic as well as biological surface modifying− Drugs are released agents – Mauro Ferrari, Univ. of Cal. Berkley directly into the targeted cells
Multi-functional therapeuticsare medicines that can be delivered tospecific areas of the body in differentways (e.g., via mouth or blood).The development of nanoscale injectable nanovectors, theyhave tools that can cross the blood brain barrier. With thehelp of MRI and targeting nanovectors, a physician can seeduring a surgery whether all of a tumor has been removed.Bad cells are targeted by the nanoparticles like lights on aChristmas tree, so that healthy tissue is obvious and a lot lessmedicine needs to be taken to ensure a cure.
Nanoshell a type of spherical nanoparticle consisting of a dielectric core which is covered by a thin metallic shell (usually gold).These nanoshells involve a quasiparticle called plasmon which is a collective excitation or quantum plasma oscillation where the electrons simultaneously oscillate with respect to all the ions.Gold nanoshells are shuttled into tumors by the use of phagocytosis wherephagocytes engulf the nanoshells through the cell membrane to form an internalphagosome, or macrophage. After this it is shuttled into a cell and enzymes are usuallyused to metabolize it and shuttle it back out of the cell. These nanoshells are notmetabolized so for them to be effective they just need to be within the tumor cellsand photoinduced cell death is used to terminate the tumor cells.
Thermal ablation ofcancer cells− Nanoshells have metallic outer layer and silica core− Selectively attracted to cancer shells either through a phenomena called enhanced permeation retention or due to some molecules coated on the shells− The nanoshells are heated with an external energy Thermal ablation of cancer cells assisted by nanoshells coated with metallic layer source killing the cancer cells and an external energy source – National Cancer Institute
Bioavailability describes the delivery of healing molecules in the body where they are needed and will do the most good.Currently, many treatments come to a haltwhen they get to the cell membrane.They can’t pass through because they don’thave the correct electrical charge. Puttingpolar (charged) molecules into a non-polar(uncharged) membrane doesn’twork. One way to get around this is to coat apolar molecule with a non-polar coatingthat allows it to pass through the membraneand deliver its treatment.
Self-AssemblyMicrocapsules automatically assemble themselvesinto a hollow sphere, doing the scientist’s work forhim or her. A microcapsule, shaped like an o, canhave antibodies or other proteins stuck on theoutside, with enzymes or other molecules inside.1) hollow microcapsulespheres with certain size “pores” in their outercoatings are made to selfassemblethrough chemical reaction with a polymer geland a salt; 2) larger moleculesare encapsulated through chemical reaction atabout the same time; 3) smallerreactant molecules are added that slip insidethe microcapsules and react with theencapsulated molecules; and 4) micro sizemedicines fl ow back out in a time releasefashion.