Nanotechnology's Prescription for Health Care

Nanotechnology will also provide advances in treating medical conditions once diagnosed. One of the most promising areas of research and development is in drug delivery technology. Conventional methods of delivering drugs, like pills, injections, and intravenous (IV) drips, do not allow precise control of the medicine's release. Nanotechnology could provide the means of gradually releasing a drug into the body so that its concentration in the blood remained level throughout treatment and targeting a specific area for drug release.

This would be especially useful in administering chemotherapy, the treatment for cancer. Chemotherapy drugs kill cancer cells, but they also attack healthy cells, causing hair loss and other severe side effects. Targeted delivery would reduce side effects and allow higher dosages, since only cancer cells would be affected. Nanoshells, nanoscale glass beads coated with gold, could someday achieve this goal. Once injected into the bloodstream, nanoshells bind to tumors. The nanoshells would then be activated by an outside laser, causing them to emit heat and kill cancer cells.

A drug's rate of release over time can be controlled by nanoscale packaging of the drug molecules. The drug can be encapsulated inside a polymer, a large carbon-based molecule, which releases the drug gradually through pores. The size of the pores determines the rate of delivery. Two other molecules show great promise in drug delivery and potentially in gene therapy, the insertion of stretches of DNA and RNA into cells to replace damaged genes. Dendrimers, a type of large artificial molecule, have pockets within them ideal for carrying drug molecules. Structures called liposomes can bond to specific cells and release the drug.

Nanotechnology even holds promise for bioengineers working on the regeneration of entire organs in the laboratory. An artificial scaffolding would be populated with cells containing a patient's genetic material. The structure would grow into the desired organ, like a kidney or liver. The customized organ would have a low risk of rejection in the body, and the patient would not have to rely on a donor. Researchers have already developed materials based on nanotubes that bond to bone, which provides an attachment for artificial joints or, potentially, a scaffolding for regeneration.