Nanotechnology/Targeting Diseases

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NanoMedicine

Helping improve humanity is one of the promises of nanotechnology. Much hope and hype has surrounded nanomedicine. Research is actively pursuing the benefits of nanotechnology enabled medicine and the promise of organ specific drug delivery and cancer treatments. But, there is no consensus among the research and medicine community that shows the toxic effects of heavy metal nanoparticles in the body when used as "treatments". This chapter will highlight some of the research findings in the nanomedicine area.

Scientists are working to find "nanostructers" for many different kinds of cures, including Parkin's and Cardiovascular Disease, treatment for cancer, nanomaterial for new artificial limbs, and nanodevices that could restore hearing and vision. Soon, nanomedicine will be able to cure many diseases and illnesses. References: http://www.medicalnewstoday.com/articles/67702.php

The scientists have found a way to deliver molecules within 'wells' of polymers that are a part of a capsule. They are also making ground medicine with particles in the nanoscale to increase effectiveness.

Source- Nanotechnology A gentle introduction to the next big idea, Written by Mark and Daniel Ranter

• eMedicine – The original open access comprehensive medical textbook for all clinical fields.
• Nanomedicine book site

Example #1: Nanosilver

For thousands of years, silver has been known to be a potent bacteria killer. However, due to the fact that silver could not dissolve well, it's efficiency as an antimicrobial has been slim. This problem has been solved by the company Nucryst Pharmaceuticals. To combat it's inability to dissolve, they use a nanocrystalline form of silver to fight off bacteria. Silver ions rapidly kill microbes in a variety of ways which include blocking the cell respiration pathway, interfering with components of the microbial electron transport system, binding DNA, and inhibiting DNA replication.

Their first product with the silver is Anticoat, a dressing for serious burns. Anticoat antimicrobial barrier dressing works to reduce or kill off bacteria, have high absorbency rates, continue working for a full 7 days, and are easy to remove without disrupting the wound. When the dressing is removed, it peels off in one piece and a new coat can be applied. A high absorbency rate is required because many wounds release a lot of body fluids and a good absorbency rate will maintain a healthy wound environment. It is usable for a week and can also be used for serious words. Also, now they are exploring the anti-inflammatory properties of silver for use in atopic dermatitis and certain respiratory conditions.

Example #2: Regenerating Neurons

There is a research team at USC that is working on producing artificial motor neurons. These neurons could serve several functions; including letting people with paralyzed limbs use their limbs again. These fake neurons would essentially take over the functions of the real motor neurons. Using this technology doctors could replace motor neurons since neurons do not grow back.

Example 3: Peptides for wound healing

Researchers at MIT have found liquids called peptides that form a nanoscale barrier in seconds, stopping the flow of blood. later. when the wound is healed, the solution breaks down and can be used by the body as new tissue. The same scientists also reported that a peptide partially restored a hamster's vision.

Examples #6: Malaria

Dr. Subra Suresh, a professor at MIT, using nanotechnology, has studied malaria, an infection spread by mosquitoes, in which tiny parasites infect the red blood cell. Using “laser tweezers” and two nano-sized glass beads fused to the red blood cell surface, he found that infected cells may be as much as 15-times stiffer than normal cells, which causes them to clog up small blood vessels. He is now looking at the effect of different genes in the parasite that may produce this effect as this may allow the finding of a treatment for this worldwide disease. "Tiny tools tackle malaria", 2005. Retrieved on 6-26-2008.</ref> [1]

Example #7: Increased drug dispersion from nanoparticles

One of the greatest prospects of nanomedicine is in drug delivery. On the most basic level current drugs ground into a smaller state have a greater surface area which allows them to dissolve more quickly in the stomach. A variation on this idea is using small crystals of medicine. These crystals allow every molecule to be close to the surface which creates an environment where even the most slow dissolving compounds will dissolve quickly.

Example #8: Drug delivery polymer nanoparticles

Drug delivery is one of the best benefits of nanomedicine. There are many different schemes for improving drug delivery, for example, molecules can be put into nanoscale cavities inside polymers. The polymer can then be swallowed as part of a tablet or pill, and when the polymer opens inside the body, the drugs can be released into the body. More complex schemes have also been developed, such as getting drugs through cell walls and into the cell. Efficient drug delivery is essential, because many diseases depend on processes within the cell, and can only be affected with drugs delivered into the cell.

Example #9: IMEDD (Intelligent MicroEngineered Drug Delivery)

IMEDD (Intelligent MicroEngineered Drug Delivery) is trying to make tiny drug deliver pumps. The researchers at IMEDD are working with Terry Conlisk, who is an engineer at Ohio State, who has made a computer model that helps small drug reservoirs pump out drugs when they are needed. They use this principal to work the pumps, "If a fluid is positively or negatively charged and there is a like charge to the inner surfaces of a channel, the charges will repel each other. The result is that the fluid will flow down the channel." In their experiments, they have been able to put almost 0.5 nL of saline per minute through a channel only 7nm wide. Medical researchers hope to use this technology to push tiny amounts of drugs into the body exactly where they are needed. They accomplish this by a technique developed by a team of scientists and engineers at ASU called photocapillarity. Photocapillarity is defined as "the microfluidic actuation of water in an enclosed capillary or microchannel using light".

Targeting Cancer

Cancer is the focus of many new nanomedicine therapies under development for repairing damaged tissues and treating and detecting cancer by developing medical interventions at the molecular scale that couples nanotechnology, clinical science, and the life sciences. People are developing innovative drug and gene delivery strategies and modulating molecular events can control cell processes such as initiating, enhancing, and maintaining macro- and micro- vasculature to ensure tissue viability, vessel networks within tissue engineered constructs and autologous tissue flaps and grafts. Developing novel synthetic, natural, or hybrid materials to control cell-material interactions, biomechanics, angiogenesis, and the in vivo release of therapeutic agents.

Molecular imaging and therapy - nanotechnology is hope to be the source of new ways to target cancer with fewer side-effects

• Cancer
• Oncology -the study and treatment of cancer

Cancer example #1: Nanoparticles Generate Supersonic Shock Waves to Target Cancer

Researchers from UCM (the University of Missouri-Columbia) and the United States Army have made a nano-sized “bomb”. This bomb can target drug delivery to cancer tumors without damage to any other cells. The nano thermites produce shock waves in the Mach 3 range. Cancer fighting drugs would be administered via a needle, and then a device would send a pulse into the tumor. The pulse would create little holes in the tumor, so the drugs can enter.

Cancer example #2: monitor post-treatment relapse

MNC is working with the Medical School at Swansea to develop a nanoscale sensor that would be put into the body and would be capable of detecting the growth of cancerous cells in patients. It would monitor post-treatment relapse. This way of finding the cancer cells at an early stage would reduce mortality rates dramatically.

Cancer Example #3: Photodynamic therapy

Photodynamic therapy (a type of treatment for cancer that is nothing like chemotherapy) is directed to hit the spot where the cancer is, it is a therapeutic idea. What happens during photodynamic therapy? They would put a metal nanodot or a molecular dot (the particle) inside your body and then they would shine a type of light to illuminate it from the outside. Then the light is absorbed by which ever particle they put in your body. So if you have a metal nanodot and it have absorbed the light the energy will heat the metal nanodot up making every tissue that it near heat up to. But with the molecular dot the light absorbed creates oxygen molecules that are very energetic. And since the oxygen molecules are highly reactive it chemically reacts or destroy the organic molecules that are beside it (example: tumors).

Cancer Example #4: NIH Roadmap's Nanomedicine initiative

NIH Roadmap's Nanomedicine initiative is working on advancing the study of nanotechnology. They hope to be able to detect cancer cells before a tumor develops and accurately destroy them, and have nano-sized pumps in your body that deliver medicines into your body where you need it. They believe they will be able to do this in ten years.

MRI - Magnetic resonance imaging

MRI Example #1: MRI nanoparticles

Biophan is a company specializing in nanomedical applications. One of their projects is to make MRIs safer for patients with microelectronic implants that include metals. By using a coating of nanomagnetic particles, these devices, including pacemakers, are shielded from the radio waves from the MRI machine and current (which could harm the patient) caused by electromagnetic radiation is reduced. It was also found that these particles could be used as contrast agents to allow for a clearer image by creating sharper contrast among the different tissue types in the body during an MRI scan. Biophan is also working towards longer lasting batteries for pacemakers and other medical devices (by using body heat), smart drug delivery, and other nanomedicine projects.

MRI Example #2: magnetic nanoparticles

Magnetic nanoparticles have shown promise as contrast-enhancing agents for improving cancer detection using magnetic resonance imaging, as miniaturized heaters capable of killing malignant cells, and as targeted drug delivery vehicles. Now, researchers at the University of Nebraska have developed a novel coating for magnetic nanoparticles that allows the particles to carry large amounts of drug and to disperse efficiently in water. This development may enable targeted delivery of water-insoluble anticancer agents or imaging agents.

The story of the 'Nanobacteria'

In 1988, Olavi Kajander discovered what he described as "nanobacteria." Something was killing his mammalian cells, and after looking closer using an electron microscope, he found something inside of the cells. However, this was not any normal bacterium- the organisms had diameters between 20 and 200 nanometers. Their sizes were too small to support a complex metabolism like the bacteria known to microbiologists. Though his nanobacteria was dismissed by most of the rest of the scientific world, Kajander had become attached to them. After multiple failed attempts to prove their scientific legibility, he connected their hard outer shells-made up of calcium phosphate- and kidney stones, which are caused by calcium compounds. It turns out that the so-called "nanobacteria" were related to, not only kidney stones, but ovarian cancer, Alzheimer's, and prostatitis. Though they are not recognized as true bacteria and have no DNA or RNA, nanobacteria can reproduce, albeit slowly. Strange. Interestingly enough, nanobacteria has been reported in underground rock and other such geological formations. Further, there are claims that nanobacteria have been found in meteorites and, after being transported into zero gravity, nanobacteria has been found to reproduce at a much faster rate than when on earth. Some wonder if nanobacteria is not really from earth, but outer space.

BioMedicine

Herb Example #1: Clinacanthus nutans

In Thailand the leaves of Sabah Snake Grass (Clinacanthus nutans) had been used by traditional healers to treat herpes infections and it's shown to have verifieable antiviral activity. It was found that C. Nutons was able to increase lymphocyte proliferation significantly and reduce the activity of natural killer cells (NK Cells) significantly. It's shown to increase immune response activity strong enough to cure different diseases. It's beliefed that it can cure cancer aswell. It possess a strong anti-inflammatory activity, because of the ability to inhibit the neutrophil responsiveness as evidenced by the significant inhibtiion of myeloperoxidase (MPO) activity. C. nutans is a plant used extensively by traditional healers of southern Thailand and North-western Malaysia as a remedy for envenomation be it snakes or venomous insects like scorpions and bees effectively. Cherdchu et al did not find any antivenin activity, that's why it's not known how it's works as Antivenom. Pannangpetch et al looked found antioxidant and protective effects against free radical-induced haemolysis properties in ethanolic extracts of the leaves of C. nutans.

Herb Example #2: Annona muricata

There is evidence indicating that the fruit's extracts selectively inhibit the growth of human breast cancer cells by downregulating expression of epidermal growth factor receptor (EGFR) in vitro and in a mouse model, but the effect has not been studied in humans.

References

See also notes on editing this book about how to add references Nanotechnology/About#How_to_contribute.