Killing machines: Anticancer treatments

Special nanoparticles are being developed that can home in and destroy cancer cells.

Among the most exciting nanotechnological possibilities are new cancer treatments.

One approach is to use nanoshells as miniature 'thermal scalpels'. The nanoshells are coated with a substance that binds them to cancer cells, and are then injected into tumours. Light from a near-infrared laser, which is harmless to healthy tissue, is absorbed by the nanoshells. The nanoshells heat up, destroying the tumour cells.

Another plan is to use quantum dots (see page 14 of the print publication) to deliver drugs directly to cancers. Dots coated in the anticancer drug Taxol and cancer-targeting molecules have already been shown to kill tumours in mice. Dots excited by near-infrared light emit energy that breaks the bonds with Taxol, releasing the drug to attack and kill tumour cells.

Many other approaches are being tested. Liposomes (artificial microscopic sacs of fluid with a phospholipid membrane) are being used to deliver DNA or RNA to cancer cells, making them more sensitive to standard chemotherapy or radiotherapy. And biodegradable nanoparticles are being used to target toxic chemicals to cancer cells, releasing their deadly cargo over a period of time.