Light-activated gold cage delivery capsule developed

A smart nanocage that can be filled with a medicinal substance and then activated using light has been developed by US researchers. The nanocage, dubbed the 'smart capsule' in a press statement issued by Washington University (WA, USA), comprises a gold cage covered with a smart polymer that responds to light, causing it to empty the contents of the cage. The cage reseals when the light is turned off.

A study describing the methods for making the capsules, as well as the tests of their performance, has been published online as part of the advance online publications programme of Nature Materials. The aim of research was to create a capsule that could be activated in the bloodstream by shining a laser onto the skin.

In tests, the team of researchers showed that the capsules could be loaded with a common chemotherapy drug (doxorubicin). After being triggered by a laser, the drug killed breast cancer cells growing in wells on a plastic plate. In another test, the researchers loaded the capsules with an enzyme that snips open the cell walls of bacteria and used it to kill a bacterium that is a normal part of the floras of our mouths and throats.

According to the researchers, the capsule could maximize a drug's beneficial effects and minimize side effects; the drug would only be released in titrated amounts near the tissue of its intended target.

www.wustl.edu