They could considerably advance the field of medicine

Nov 14, 2009 19:01 GMT  ·  By
Fully biodegradable, semiconducting transistors have been developed at the Stanford University
   Fully biodegradable, semiconducting transistors have been developed at the Stanford University

Scientists at the Stanford University announce the completion of a new class of electronic devices, fully biodegradable organic transistors. The materials hold great promise for the field of medicine, where they could be used to control temporary medical implants, before being harmlessly absorbed within the organism without any side-effects. The new transistors could also be used for advanced drug delivery systems that act over time inside the body, experts add. The innovation would allow nanoparticles carrying drugs to be activated externally, via radio frequencies, Technology Review reports.

Robert Langer, a professor at the Massachusetts Institute of Technology (MIT), believes that the transistors, if produced at low costs, could soon become an integrated part of medical procedures. During a complex surgery, doctors could implant transistor-controlled nanoparticles in the body, and then release the drugs these particles have been loaded with over time, whenever needed. Control would be achieved either via external magnetic fields, or by subjecting the controlled capsules to radio or microwave frequencies.

The new achievement comes on the heels of a different one, made at the Tufts University and the University of Illinois in Urbana-Champaign earlier this month. Researchers there reported at the time that they had managed to complete a method of producing silicon nanoelectronics embedded in silk substrates, which are also biodegradable. But SU Engineering Professor Zhenan Bao's team is the first to produce new classes of electronics directly from fully degradable, semiconducting materials. They dissolve in less than 70 days in water, leaving behind only metal electrodes, just nanometers thick.

Details of the amazing, new accomplishment are published in the latest online issue of the respected scientific journal Advanced Materials. US Food and Drug Administration (FDA)-approved plastics are used for the materials, the SU team reports. The electrical contacts are made out of gold and silver, while the semiconducting material resembles the skin pigment known as melanin. All of these components were verified to be safe for use inside the human body in previous studies, without adverse effects on the immune system, local cell groups, or overall health.