Nano-Scale Drug-Delivery System Is Good as Gold

Here is a gilded cage worth checking into. A tiny golden holding cell covered with a “smart” polymer that responds to light—opening to empty its contents when exposed to light and resealing when the light is turned off—has been developed in Younan Xia’s laboratory at Washington University in St. Louis, MO, USA. The nanocage is designed to release carefully titrated amounts of a drug in proximity to the target tissue, thus maximising its therapeutic value while minimising its side effects. An advanced online version of the article was made available at the beginning of this week on the Nature Materials site.

Once the cages have been formed, they are shaken in a solution of the drug that is to be loaded onto the carrier at a temperature above the polymer’s critical temperature. As the cages cool, the polymer chains stand up like brushes, sealing the cage pores. To release the drug, the cages are exposed to laser light tuned to their resonant frequency. This heats them just enough to drive the polymer over its critical temperature, causing the  polymer chains to collapse, open the pores, and release the drug. The cage can be resealed simply by turning off the light.

Tags: Drug delivery, nanocage, Younan Xia