Nanotechnology in Medicine

Nanotechnology in Medicine 
Ideas of modern nano-has been mentioned Richard Feynman in his famous lecture "There's a lot of space at the bottom" in 1959. Then he talked about the possibility of chemical manipulations at the atomic level, and suggested that when a patient is simply "swallow a surgical machine," which will come into place and everything patched. It took 50 years and scientists are still struggling with the creation of such a surgeon, but Feynman, no doubt, would have impressed the fact that we have done to date.Nanomedicine is firmly gaining a place in the field of drug delivery and diagnostics. 
Such an area of ​​knowledge of nanotechnology in medicine is relatively young. The term has appeared relatively recently, little more than 15 years ago, and the direction it is currently in its infancy. Its methods are emerging from laboratories and most of them so far exists only in draft form. However, according to most experts, the methods of nanotechnology in medicine will be fundamental in the 21st century. For example, the U.S. National Institutes of Health Nanomedicine included in the top five priority areas of medicine in the XXI century. 

How it all began 
Of course, the realities of nanomedicine does not quite correspond to Feynman's dreams.Silicon electronics boom 80 has provided chemists the tools necessary to manipulate matter at the molecular level. But then, scientists did not think about the possible development of biomedicine. "We were actually played, simply because we had such an opportunity," - said one of the pioneers of nanotechnology, a chemist at the University of California, Paul Alivizatos. One of his most notable trends was the work of fullerenes. "I believe that when it became clear how many would be able to do in the field of medicine," - says a scientist - "Always there is something unexpected, such as the use of fullerenes as carriers of drugs." 
Many of the discoveries in the field of nanotechnology in medicine were made unexpectedly. In the mid-90-pharmacologist Professor Volkmar Vayssig of Arizona found that a well-known composite material can be self-assembled into a hollow sphere with a diameter of 50 nm, similar to liposomes, and that this sector can deliver DNA or other cargo through the cell membrane to the mitochondria. At the moment it is not interested, but a few years later, experts have linked a number of diseases with malfunction of mitochondria and different groups of scientists are now working to develop a point of substance delivery to the mitochondria by the method of Vayssiga. 
Warren Chan of the University of Toronto studied quantum dots, nanoparticles of cadmium on the basis of diameter of 1 to 6 nm, which other researchers have tried to apply for manufacturing solar cells. However, Chang has found that these points, which emit light of different wavelengths, in other words, different colors depending on the size, you can "stick" to the proteins in the cell and make them an excellent diagnostic tool. They give a glow to ten times stronger than previously used materials and much less prone to photobleaching, so that they work much longer. At present, virtually every major university conducts experiments with quantum dots in organic media. 

Fast trade with nanolekarstvami 
Nanotechnology in medicine most associated with nanorobots. The best-known and promising direction of nanomedicine is the spot delivery of drugs. The idea of ​​it we have already outlined - the nanoparticle acts as a carrier of several molecules of the drug, which are shipped directly to the affected area. 
One of the focal areas of the point of delivery is cancer. Perhaps it would be a panacea for nanotechnology to this terrible disease. The main idea is the initiation of apoptosis, reducing the number of cancer cells, with chiseled deliver cytotoxins - a special type of antibodies that damage the cells as they interact with their antigens, or disrupt cell RNA, so it is not healthy cells are damaged, which typically occurs in modern cancer treatments.Nanoparticles can be created so that the immune system will not detect and reject them.For this purpose, heavy metals such as gold or cadmium, which, owing to their high ratio of surface area to volume is easy to cover nucleic acids and proteins. 
Most of the tests carried out until these technologies in laboratory animals, but some things and on people. Thus, the delivery system on the gold particles to tumor necrosis factor-α made is in the second phase of clinical trials. Usually the drug is administered in small doses because of its high toxicity, but when he delivered the nanoparticles, the drug is released directly into the tumor cells, so that the dosage can be drastically increased. 
How about the outlook for drugs with a modified delivery system specialists can be judged from the fact that at present the market share of these drugs is 20% of the total market of pharmaceuticals. 
Drug delivery system can also be used to carry DNA fragments containing the gene, whose mission - to perform a particular operation, adjustment, start or stop a particular biological mechanism. For example, people with diabetes, thrombophlebitis, there are sores. They appear as a result of circulatory disorders and lead to tissue necrosis.Typically, this leads to amputation or death. However, an innovative medicine offers the following solution: we can take a gene known to us sprouting blood vessels, which for some reason these people are not working, synthesize it, and then enter in the patient tissue. For the last operation we momestim gene in a nanoparticle, surrounded by special substances which are easily destroyed, attach the gene type of the virus, because our cells are able to capture the virus. As a result, under the guise of a gene of the virus approaches the cell, she grabs it and carries inside the nucleus. At the core of the synthesized gene information can be read, resulting in starts to stimulate the growth of blood vessels. In a couple of months a person grow new blood vessels, and amputations can be avoided. 
In Russia, the development of targeted delivery systems are maintained in two ways: passive directional transport (facilitated penetration of natural barriers), and specific delivery ("recognition" of abnormal tissue), which meets world standards of research in this area. Practical results in the near future can be achieved in the use of phos-folipidnyh particles, liposomes and fullerenes as containers for drug delivery (including vaccines). In the long run to Russian scientific basis can bring to a commercial prototype-specific delivery systems based on antibodies or aptamers and selectively bind to pathologically altered cells. 

Illumination from the inside 
A lot of scientists attracts the potential of nanotechnology for the diagnosis. Innovative technology allows detailed monitoring of tumor growth and movement of chemicals. The use of certain types of nanoparticles allows the visualization of individual lifetime of pathologically altered cells and even molecules, which are markers of common diseases.Also, fluorescent nanoparticles can accumulate in tumor tissues, thus facilitating their work cut out a surgeon who will be seen with the naked eye, whether he missed somewhere sites of metastases. 
Over the past few decades, imaging techniques have become a crucial tool in the diagnosis of the disease. However, nanotechnology may further improve the performance of a nuclear magnetic resonance and computed tomography, giving them opportunities far beyond the modern diagnostic equipment. 
Contrast agent for molecular diagnostics consists of nanoparticles, which are connected with visual components and specific antibodies, or any other molecules that can find the target. When a contrast dye is injected into the bloodstream, its search components interact with target structures on the surface of the patient cells on a "key-lock", and visual components fall into the diseased tissues. After this is "regarded as" visualize information.One European company develops contrast agents based on nanoemulsion perftorkarbona, each of which carries a drop of several thousand atoms of gadolinium.Thus, the sharp increase contrast. 
Complex molecular contrast agents that are created on the basis of nanotehnoloy not yet available for clinical practice, however, already implemented a simple contrast media, which consist of nanoparticles of iron oxide. They provide high contrast in the diagnosis of liver diseases. 

Issues of internal security 
However, amid bright prospects for nanomedicine cautious voices are heard, warning about the possible toxicity of nanoparticles of treatment. Some studies conducted in cell cultures showed that the nanoparticles are cytotoxins. However, animal studies do not allow one to come to that conclusion. The researchers explain this by the fact that in experiments on cell cultures were introduced too many nanoparticles. 
In this connection we may refer to the opinion of Academician, Dean of the Faculty of Basic Medicine, Moscow State University, Vsevolod Tkachuk Arsenievich. "We can make the nanoparticles move not chaotically, but directionally, it is reasonable, so we will ensure the delivery of drugs to the desired portion of the cell - says academic - but there are some problems associated with nanoparticles. The fact is that when the material is milled and it acquires new properties, which can be harmful. For example, they may cause the aggregation of proteins, changing the structure of proteins. However, aggregation can be avoided if properly constructed nanoparticle charge and set the correct size, to give the desired roughness or to select the correct dose. Paracelsus said that "all the world is poison, and only makes a fraction of the substance safe." To do this, we double-check them before using. Let's see how they affect the morphology, structure, the division, movement, life in the cell. " 
Another aspect that causes concern test - the consequences of the accumulation of metals in the body of indecomposable, which form nanoparticles. A possible solution to this problem would be Self-particles. 
Despite all the fears, the prospects for nanomedicine remain generally encouraging.Optimists predict that scientists will soon be possible to combine already created by the individual elements, such as engines, cranes, cargo space in the form of nanocapsules, and a full nanorobot, which will move through the body and diagnose disease processes that purify the blood, enhance cells' to regulate the balance of substances to destroy diseased cells and infection