It is the branch of science that deals with fabrication of materials and devices on nanoscale. Medicine has always been integral part of human life and will always continue to do so. Hence applying nanotechnology in the field of medicine is bound to benefit the human race.
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.
It deals with the comprehensive monitoring, Control, Construction, Repair, Defense and Improvement of all human biological systems. These are done by the employment of molecular machine systems making use of using engineered nanodevices and nanostructures to maintain and improve human health at the molecular scale.
Medicinal nanobiotechnology aims in:
1. Early and faster Detection or diagnosis of diseases.
2. Efficient methods of treatment.
In this paper special emphasis has been made on certain diseases that are highly prevalent in India.
The paper has been divided into four main sections:
• Diagnosis of diseases
• Treatment of diseases
• Drug delivery systems
• Future prospects of nanomedicine
DIAGNOSIS OF DISEASES:
The detection and diagnosis of diseases are playing a major role in the field of medicine because the latest diseases like cancer, HIV have the ability to spread within the body without giving any symptoms. Cancer can be detected usually only after it spreads through most of the body that is after is passes through its primary and secondary stages.
HIV, the killer disease is a silent killer and the symptoms surface only after 5 to 10 yrs after the initial infection. It has been demonstrated that very small human melanoma tumors can be detected using nanomedicine.
Specially designed nanoparticles called "Quantum dots" can reveal tiny cancerous tumors that are invisible by ordinary means of detection.
Nanoparticles are engineered to carry almost 10,000 metal ions such as cadmium selenide ions and also specific antibodies. When these nanoparticles are injected into the human body, the antibodies being specific bind to cancerous cells and when the body is exposed to U.V radiations the cadmium selenide ions emit florescence. This can be detected by an MRI scan, nuclear imaging or by CT scan. This creates a high-density contrast image enabling the doctors to estimate how many cancerous cells are present and the extent to which they have spread. This technique is helps the doctors to discern whether the cancerous cells are still malignant even after radiation therapy. This method is more effective over chemotherapy as accurate dosage of drugs can be injected proving to have no side effects.
DRUG DELIVERY TECHNIQUES:
After the diagnosis of a disease there should be effective ways to deliver the drug to the affected parts of the body. In India Diabetes is one of the most prevalent diseases. It's estimated that by 2025 India alone will have 7 million cases, almost 80% of the Indians. Experts have attributed this due to the sedentary lifestyles followed.
Insulin is a drug that is being used most widely for controlling the blood glucose level in diabetic patients. Insulin however cannot be taken orally as the stomach acids degrade insulin. This has lead to endeavors in nanomedicine to devise a method of drug delivery to effectively deliver insulin. A nanoparicle made of carbohydrate polymer called chitosin obtained from the shells of shrimps encapsulates the insulin drug, making it possible to deliver the drug into the small intestine where it is absorbed by the body. This in turn reduces the blood sugar level.
TREATMENT OF DIESEASES:
Nanomedicine has ventured out in the treatment of cancer especially breast and prostrate cancer using a molecule called as Dendrimer. This molecule has over a 100 hook like features attached to it. Folic acid is then attached to some of these hooks and to the rest of the hooks anti-cancer drugs are attached. When injected to the body cancerous cells having more vitamin receptors tend to absorb these vitamin-laden dendrimers. Once the dendrimer attaches to the cancerous cells the anti-cancer drugs are transferred from the molecule to the cancerous cells. In this way the cancer cells are eliminated and no other cells.
FUTURE PROSPECTS OF NANOMEDICE:
Nanorobots: a computer-controlled robotic device constructed of nanometer-scale components to molecular precision, usually microscopic in size ("nanobot"). Nanorobots called Respirocytes mimic the action of the natural hemoglobin-filled red blood cells. A respirocyte can deliver 236 times more oxygen per unit volume than a natural red cell. This nanorobot is far more efficient than biology. Respirocytes will have pressure sensors to receive acoustic signals from the doctor, who will use an ultrasound-like transmitter device to give the respirocytes commands to modify their behavior while they are inside the patient's body. This method helps the doctors to know about the internal conditions of the body.
Nanofilters are more effective than conventional filters as it allows essential nutrients to pass while blocking out contaminants and could be used in implantable artificial organ components. Such implanted devices could monitor the condition of the patient and release hormones or medication as needed in the case of diabetics and heart patients.
One of the more futuristic applications of nanomedicine in the body would be to improve gene therapy techniques. A nanoarray of short strands of artificial DNA within a silicon circuit could be inserted to act as a probe and analyze the genetic sequence for deformities. Nanoarray could also be used to identify foreign substances in the body and alter genes to correct genetic disorders. Defective genes can be replaced from outside, but DNA cannot pass through cell membrane and hence needs a transporter. Here nanotubes can be used. These are cylindrical molecules whose sides are formed from a lattice of carbon atoms. They are nine times stronger than steel and have the ability to transmit 1,000 times more electrical current than copper. They are also chemically stable and highly resistant to heat.
Tissue regeneration / repair:
Using the mammalian visual system as a model, a self-assembling peptide nanofiber scaffold was designed to create a permissive environment for axons not only to regenerate at the site of an acute injury, but also to knit the brain tissue together. In a severed optic tract regenerated axons reconnect to target tissues with sufficient density to promote functional return of vision. Implantable prosthetic devices and nanoscaffolds for use in the growing of artificial organs are other goals of nanotechnology researchers. Nanoengineering of hydroxyapatite for bone replacement can also be done.
Based on our research we have led to the conclusion that nanomedicine indeed holds a promising future, as it is very effective, efficient, accurate and versatile in nature. It has also been found out that nanomedicine is very economical in the long run as it requires very less amount of materials and manpower.
About Author / Additional Info:
A scientific writer