Simple electrical on/off switch controls drug-delivering membrane

One problem with implanted drug-delivery devices that depend on external signals--such as ultrasound, light or magnetism--for activation is that they require large or specialized equipment to operate. Korean researchers think they've found a solution in simple, easy-to-generate electrical signals. They've created a membrane that can respond to electrochemical signals to release therapeutics.

NPG Asia Materials reports on the work of Jin Kon Kim of Pohang University of Science and Technology in Korea and his porous membrane that stores and releases drug molecules according to an external electric signal. The same signals going into the device could also create feedback and enable remote control outside the body when the delivery system is combined with a sensor or microchip.

The membrane is made up of aluminum oxide with pores of around 400 nm in diameter. Kim's team deposited a thin layer of gold and a conducting polymer that contains negatively charged ions. Changes in the device's electrochemical state has an impact on whether these tiny pores are open or closed. The researchers could quickly switch these pores from one state to another more than 1,000 times.

The researchers are currently developing these pulsatile drug delivery implants out of biodegradable polymers.

- see the story in NPG Asia Materials
- and the abstract in Nano Letters