NANOTECHNOLOGY IN MEDICINE T.SUJANA T.VINOD ¾ CSE ¼ MEC CHAITANYA ENGG COLLEGE GAYATRI VIDYA PARISHAD KOMMADI MADHURAWADA VISAKHAPATNAM VISAKHAPATNAM Sujana_t@rediff.com email@example.com 1.INTRODUCTION: - With in few decades, and perhaps sooner Nanotechnology is emerging as enabling technology that is expected to redesign the future of several technologies and products and is expected to replace many existing technologies in use today. This technology is to change major aspects of our lives and to lead for generation of new capabilities, new products and ultimately new markets. One major aspect associated with Nanotechnology is that it is multi-disciplinary technologies with wide spectrum of applications – Nanomaterials, Nano-electronics, Nano-biotechnology, Nanomedicine and Nanosurgery etc. as broad classification. If this possible, the policy implications are enormous. Nanotechnology is manufacturing at molecular level of building things from nano-scale components. The word Nano comes from Greek word,”Nanos” meaning dwarf. Nano is factor of one-billionth. “Thinking small to think big” is a Best caption for Nanotechnology 2.PIONEERS: - Norio Taniguchi at the University of Tokyo coined the word nano technology. Later during 1950's Arthur Von Hipper, an electrical engineer from the Massachusetts Institute of Technology coined the term 'molecular engineering' and predicted the feasibility of constructing the monomolecular devices. In 1959 the Nobel Laureate physicist Richard Fey Mann was he first to present the concept of nanotechnology to the world and Suggested that the manipulation of individual atoms could revolutionize science. Later in 1979 two IBM researchers invented the scanning Tunneling Microscope. Eric Drexel, chairman of the Foresight Institute in the mid 1970's came to a conclusion in his book "Engines of Creation", the term "nano" is a specialized subset of Nanotechnology or MNT (Molecular Nanotechnology) as it is now called. 3.NANOTECHNOLOGY IN MEDICINE - A NEED:- As is the awareness with us, Diseases and ill-health are caused by damage at the molecular and cellular level, which gradually multiplies affecting the system as a whole. The medicine/drug consumed to cure a particular ailment has to survive a long journey through the stomach and reach the intestine intact and then come into circulation crossing the intestinal wall. Once in blood, it gets filtered through the liver and travels through the body resisting acids of digestive juices, jump membrane barriers and then act on specified area of damage in the system. The challenges in the existing medicinal systems are for protein-based pharmaceuticals which are broken down when taken orally, killer diseases are growing more resistive to drugs, surgical tools are large and crude much suited to tear and injure rather than heal and cure. Molecular Nanotechnology has emerged as three-dimensional positional control of molecular structure to create materials and devices to molecular precision. The human body is comprised of molecules hence the availability of molecular Nanotechnology is progressing dramatically to support human medical services. Nanomedicine will use molecular knowledge to maintain and improve human health using/employing molecular machine system to address medical problems. 4.NANOTECHNOLOGY – FOR HEALTH SYSTEMS:- Nanotechnology has led to a major development in the area of health and medicine. This could happen because of integration of biotechnology and Nanotechnology. This confluence led to the exciting developments of Nano-devices having bio-capabilities. For e.g. Nanorobots for medical diagnostics, genetic testing, new kinds of drug-delivery systems to pervade the blood stream target contaminated cells, artificial replacement and placebos at the nanoscales. The supportive developments are a group of devices called MEMS (Micro Electro Mechanical Systems) devices that consist of tiny elements manufactured using lithographic techniques to achieve micro-dimensions that function like traditional larger devices. The integration of biotechnology, nanotechnology and information technology has a very large impact on MEMS and the efforts are now towards tinier MEMS and these devices are now known as NEMS (Nano Electro Mechanical Systems) and find applications in medicine, hospital, gathering information about body conditions, medicine transportation in the body, rapid deployment of environment friendly technology to reduce environmental degradation. 5. APPLICATIONS: - (i) BUCKYBALLS: - "It is the roundest and most symmetrical large molecule known to man. Buckministerfullerine continues to astonish with one amazing property after another. Named after American architect R. Buck minister Fuller, who designed a geodesic dome with the same fundamental symmetry, C60 is the third major form of pure carbon; graphite and diamond are the other two. AKA: C60 molecules & Buckministerfullerine. Molecules made up of 60 carbon atoms arranged in a series of interlocking hexagons and pentagons, forming a structure that looks similar to a soccer ball C60 is actually a "truncated icosahedrons", consisting of 12 pentagons and 20 hexagons. It was discovered in 1985 by Professor Sir Harry kroto, and two Rice University professors, chemists Dr. Richard E. Smalley and Dr. Robert F. Curl Jr., and The only molecule composed of a single element to form a hollow spheroid "The buckyball, being the roundest of round molecules, is also quite resistant to high speed collisions. In fact, the buck ball can withstand slamming into a stainless steel plate at 15,000 mph, merely bouncing back, unharmed. When compressed to 70 percent of its original size, the buckyball becomes more than twice as hard as its cousin, diamond". (ii) NANOTUBES: - A one-dimensional fullerene (a convex cage of atoms with only hexagonal and/or pentagonal faces) with a cylindrical shape. Carbon nanotubes discovered in 1991 by Sumio Iijima resemble rolled up graphite, although they cannot really be made that way. Depending on the direction that the tubes appear to have been rolled (quantified by the 'chiral vector'), they are known to act as conductors or semiconductors. Nanotubes are a proving to be useful as molecular components for nanotechnology. Strictly speaking, any tube with nanoscale dimensions, but generally used to refer to carbon nanotubes, which are sheets of graphite rolled up to make a tube. A commonly mentioned non-carbon variety is made of boron nitride, another is silicon. These no carbon nanotubes are most often referred to as nanowires. The dimensions are variable (down to 0.4 nm in diameter) and you can also get nanotubes within nanotubes, leading to a distinction between multi-walled and single-walled nanotubes. Apart from remarkable tensile strength, nanotubes exhibit varying electrical properties (depending on the way the graphite structure spirals around the tube, and other factors, such as doping), and can be super conducting, insulating, semi conducting. Nanotubes can be either electrically conductive or semi conductive, depending on their helicity, leading to nanoscale wires and electrical components. These one- dimensional fibers exhibit electrical conductivity as high as copper, thermal conductivity as high as diamond, strength 100 times greater than steel at one sixth the weight, and high strain to failure. NASA JSC - Carbon Nanotubes a nanotube's chiral angle--the angle between the axis of its hexagonal pattern and the axis of the tube--determines whether the tube is metallic or semi conducting. Nanotubes under Stress a graphene sheet can be rolled more than one way, producing different types of carbon nanotubes. The three main types are armchair, zigzag, and chiral. Examples Carbon nanotubes possess many unique properties, which make them ideal, AFM probes. Their high aspect ratio provides faithful imaging of deep trenches, while good resolution is retained due to their nanometer-scale diameter. These geometrical factors also lead to reduce tip-sample adhesion, which allows gentler imaging. Nanotubes elastically buckle rather than break when deformed, which results in highly robust probes. They are electrically conductive, which allows their use in STM and EFM (electric force microscopy), and they can be modified at their ends with specific chemical or biological groups for high-resolution functional imaging. Professor Charles M. Lieber Group CNT exhibits extraordinary mechanical properties: the Young's modulus is over 1 Tera Pascal. It is stiff as diamond. The estimated tensile strength is 200 Giga Pascal. These properties are ideal for reinforced composites, nanoelectromechanical systems (NEMS). Carbon Nanotube Transistors exploit the fact that nm- scale nanotubes (NT) are ready-made molecular wires and can be rendered into a conducting, semi conducting, or insulating state, which make them valuable for future nanocomputer design. ... Carbon nanotubes are quite popular now for their prospective electrical, thermal, and even selective-chemistry applications. Any potential application have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects. One, hydrogen storage, is clouded by controversy. Nanotube cost, polydispersity in nanotube type, and limitations in processing and assembly methods are important barriers for some nanotechnology applications 6.FURTHER POSSIBILITIES: - "Living organisms are naturally-existing, fabulously complex systems of molecular nanotechnology." - Dr. Gregory Fahy . The above statement raises the interesting possibility that machines constructed at the molecular level (nanomachines) may be used to cure the human body of its various ills. This application of nanotechnology to the field of medicine is commonly called as nanomedicine. (i) NANOROBOTS (Is It Possible?): - Nanorobots are nanodevices that will be used for the purpose of maintaining and protecting the human body against pathogens. They will have a diameter of about 0.5 to 3 microns and will be constructed out of parts with dimensions in the range of 1 to 100 nanometers. The main element used will be carbon in the form of diamond / fullerene nanocomposites because of the strength and chemical inertness of these forms. Many other light elements such as oxygen and nitrogen can be used for special purposes. To avoid being attacked by the host’s immune system, the best choice for the exterior coating is a passive diamond coating. The smoother and more flawless the coating, the less the reaction from the body’s immune system. Such devices have been designed in recent years but no working model has been built so far. A navigational network may be installed in the body, with stationkeeping navigational elements providing high positional accuracy to all passing Nanorobots that interrogate them, wanting to know their location. This will enable the physician to keep track of the various devices in the body. These Nanorobots will be able to distinguish between different cell types by checking their surface antigens (they are different for each type of cell). This is accomplished by the use of chemotactic sensors keyed to the specific antigens on the target cells. When the task of the Nanorobots is completed, they can be retrieved by allowing them to exfuse themselves via the usual human excretory channels. They can also be removed by active scavenger systems. This feature is design-dependent. FIELDS OF APPLICATION: - Some possible applications using Nanorobots are as follows: 1. To cure skin diseases, a cream containing Nanorobots may be used. It could remove the right amount of dead skin, remove excess oils, add missing oils, apply the right amounts of natural moisturizing compounds, and even achieve the elusive goal of 'deep pore cleaning' by actually reaching down into pores and cleaning them out. The cream could be a smart material with smooth-on, peel-off convenience. 2. Medical nanodevices could augment the immune system by finding and disabling unwanted bacteria and viruses. When an invader is identified, it can be punctured, letting its contents spill out and ending its effectiveness. If the contents were known to be hazardous by themselves, then the immune machine could hold on to it long enough to dismantle it more completely 3. Devices working in the bloodstream could nibble away at arteriosclerotic deposits, widening the affected blood vessels. Cell herding devices could restore artery walls and artery linings to health, by ensuring that the right cells and supporting structures are in the right places. This would prevent most heart attacks. 4. A mouthwash full of smart nanomachines could identify and destroy pathogenic bacteria while allowing the harmless flora of the mouth to flourish in a healthy ecosystem. Further, the devices would identify particles of food, plaque, or tartar, and lift them from teeth to be rinsed away. 7.HOW LONG?: - The abilities discussed here might well take years or decades to develop. It is quite natural to ask: "When might we see these systems actually used?" The scientifically correct answer is, of course, "We don't know." That said, it is worth noting that if progress in computer hardware continues as the trend lines of the last 50 years suggest, we should have some form of molecular manufacturing in the 2010 to 2020 time frame. After this, the medical applications will require some additional time to develop. The remarkably steady trend lines in computer hardware, however, give a false sense that there is a "schedule" and that developments will spontaneously happen at their appointed time. This is incorrect. How long it will take to develop these systems depends very much on what we do. If focused efforts to develop molecular manufacturing and its medical applications are pursued, we will have such systems well within our lifetimes. If we make no special efforts the schedule will slip, possibly by a great deal. .
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