Electrically Controlled Release of Dopamine from Nanoporous Conducting Polymers

Conducting polymers are synthesized on electrode surfaces, conduct electricity, and can incorporate different molecules. These properties make them ideal for biocompatible application to interface with the nervous system, particularly for drug release. This thesis describes the development of system based on nanoporous conducting polymers for the controlled release of dopamine. Polypyrrole, a conducting polymer, was demonstrated to release the neurotransmitter dopamine when electrically stimulated. Dopamine release from nanoporous and non-nanoporous polypyrrole films was characterized. Diffusion from unstimulated polypyrrole accounts for much of the dopamine release, while a fraction of the dopamine was released in a controllable fashion when the polypyrrole film was stimulated. Dopamine was retained by holding the releasing electrode at a negative potential. Dopamine release was quantified by fast-scan cyclic voltammetry using carbon-fiber microelectrodes.Successful controlled release of dopamine from conducting polymer films is promising for treatment of neurological conditions characterized by low dopamine levels, neuroscience research investigating the effects of neurotransmitters on network activity, and it also serves as a model system for controlled release of other similar molecules of pharmaceutical interest