Remote Control Drug Delivery System Developed

The biggest challenges in drug delivery are getting them to where they need to be within the body and timing its release. Scientists at the Massachusetts Institute of Technology may have found an answer to the second problem, according to a study released on the early online edition of the Proceedings of the National Academy of Science February 12.

Kris Wood, Nicole Zacharia, and Daniel Scmidt, working under the supervision of chemical engineering professor Paula Hammond, have developed a material that can be implanted in the human body, and triggered to release all, or some, of the chemicals bound to the thin film with a small, directed, electrical discharge.

The films were fabricated in thin layers, building them up to approximately 150 nanometers in thickness from a compound known as Prussian blue, which is approved as safe for human use by the Food and Drug Administration (FDA). Prussian blue is a common pigment for painters, and is the compound that once gave blueprints their distinctive blue hue. By placing alternating layers of Prussian blue with the chemical agent, the team at MIT achieved one of the first remote controlled drug delivery systems.

The thin film technology could be used for drug delivery for such conditions as cancer, in which the film would be embedded adjacent to a tumor, and the anti-cancer drugs released by remote control. The films can be coated onto a surface of any size or shape, offering better design flexibility than microfabricated drug delivery systems.

"You can mete out what is needed, exactly when it's needed, in a systematic fashion," said Hammond in a press release from MIT. Hammond says the films will be easy to mass produce using existing methods, and could see use in medical implants and other devices.

One of the potential uses for the Prussian blue films are for long term therapies. By implanting a device coupled with a biosensor capable of measuring blood sugar, the film could automatically be triggered by receiving a small jolt of electricity to release insulin for diabetic patients.

"You could eventually have a signaling system with biosensors coupled with the drug delivery component," said Schmidt, a graduate student at MIT and one of the principal authors of the paper.

Other authors on the paper are Stefani Wrightman, and Brian Andaya. Work was funded by the National Science Foundation, the Office of Naval Research and MIT's Institute for Soldier Nanotechnologies.