Platinum wire implants coated with PEDOT/carbon nanotube conducting polymer films in the brain of rats: A histological evaluation

Platinum (Pt) implants coated with poly (3, 4-ethylenedioxythiophene)/carbon nanotube (PEDOT/CNT) composite films were implanted into the brain of rats, and the brain response was evaluated 6 weeks after the implantation. The surface morphology of Pt implants with and without the PEDOT/CNT coating was studied using scanning electron microscopy (SEM). After 6 weeks post-implantation, the expression of laminin (vascular endothelial marker) and neuronal nuclei (NeuN, neuronal marker) were evaluated by immnohistochemistry. It is revealed that the obvious improvements of the surface density of blood vessels and neurons aound the Pt implants with the coating, which were evidenced by laminin and NeuN staining in the zone within the distance of 150 mu m to the implant interface. These results suggest the PEDOT/CNT composite films can improve the biocompatibility of the Pt electrodes while it is implanted in brain.