Surface Modification of Implantable Neural Micro-Electrode Arrays
Time and Place
Mauldin Auditorium (NSH 1305)
Interfacing brain to external electronics has enormous research and therapeutic importance. Implantable neural microelectrode arrays allow us to stimulate neurons or record neural activities from the central nervous system. The silicon based microfabrication technology has made it possible to manufacture neural probes that are small yet have a sophisticated arrangement of electrodes that can communicate with neurons individually. These neural probes have been successfully used in acute neural stimulation and recording. However, they suffer a general failure in chronic application due to the electrode/brain tissue mismatch. Various surface modification approaches are being pursued in our lab to improve the neural electrode/brain tissue interface. On the electrode sites, conducting polymers were electrochemically deposited together with different dopants. Biomolecules such as neuron promoting peptides have been incorporated as dopants to promote cell attachment on or neurite outgrowth to the electrodes. It was found that conducting polymer coatings significantly reduced the electrode impedance which is beneficial for the detection of small amplitude neural signals. On the silicon region of the neural probe, the surface was chemically modified to be consisting of polyethylene glycol (PEG) and neuron adhesion molecule L1. PEG is a non-fouling material that inhibits non specific binding of proteins and cells, while L1 can promote neuron adhesion and survival on the probe or at the vicinity. An electrically controlled drug release system via conducting polymer electrode is being explored to locally deliver drugs or neurotrophic factors to either minimize the reactive tissue reaction or promote neuronal ingrowth.
Xinyan Tracy Cui is an Assistant Professor of
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