Organic bioelectronics in medicine

A major challenge in the growing field of bioelectronic medicine is the development of tissue interface technologies promoting device integration with biological tissues. Materials based on organic bioelectronics show great promise due to a unique combination of electronic and ionic conductivity properties. In this review, we outline exciting developments in the field of organic bioelectronics and demonstrate the medical importance of these active, electronically controllable materials. Importantly, organic bioelectronics offer a means to control cell-surface attachment as required for many device-tissue applications. Experiments have shown that cells readily attach and proliferate on reduced but not oxidized organic bioelectronic materials. In another application, the active properties of organic bioelectronics were used to develop electronically triggered systems for drug release. After incorporating drugs by advanced loading strategies, small compound drugs were released upon electrochemical trigger, independent of charge. Another type of delivery device was used to achieve well-controlled, spatiotemporal delivery of cationic drugs. Via electrophoretic transport within a polymer, cations were delivered with single-cell precision. Finally, organic bioelectronic materials are commonly used as electrode coatings improving the electrical properties of recording and stimulation electrodes. Because such coatings drastically reduce the electrode impedance, smaller electrodes with improved signal-to-noise ratio can be fabricated. Thus, rapid technological advancement combined with the creation of tiny electronic devices reacting to changes in the tissue environment helps to promote the transition from standard pharmaceutical therapy to treatment based on 'electroceuticals'. Moreover, the widening repertoire of organic bioelectronics will expand the options for true biological interfaces, providing the basis for personalized bioelectronic medicine.