Histological evaluation of polyesterimide-insulated gold wires in brain

Polyesterimide-coated gold wires were implanted subdurally on the parietal cortex of rabbits for 16 weeks. Light microscope examination of the implant sites showed no evidence of toxicity. There was no inflammatory response of the adjacent parenchyma. Gliosis in the molecular or neuronal layers was only slight to moderate. Overall, the polymer demonstrated good biocompatibility at 16 weeks after implantation. Future, long-term biocompatibility studies of this material are indicated, including evaluation of tumourigenic properties.