The Effect of Biodegradable Drug Release Coatings on the Electrical Characteristics of Neural Electrodes

This study describes how drug eluting coatings affect the signal quality of implantable microelectrodes. Polyimide-Platinum neural probes were micro fabricated and coated with a biodegradable polymer loaded with drug eluting nanoparticles. Electrical impedance spectroscopy was used to study how the coating affects electrical recording and stimulation characteristics. The measurements were performed in vitro and it was found that the biodegradable film slightly modified the measured impedance phase by +3deg at 10 kHz but not the magnitude. This change in impedance is permanent but does not adversely affect the recording and stimulation characteristics of the device. This result demonstrates the compatibility of controlled release drug coatings with neural probes.