Biocompatibility of wire electrodes improved by MPC polymer coating

We investigated the use of poly (2-methacryloyl-oxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC polymer) coating to suppress the adsorption of protein by a wire surface. Reduced adsorption would slow the encapsulation of wires implanted in a living body. Coated and uncoated gold, silver, and tungsten wires were implanted into rat brain. The silver and tungsten coated wires had a significantly lower immunoreactive astrocyte count compared to the reference wires. These results demonstrate that coating wires with MPC polymer can reduce encapsulation. The use of such wires for implanting microelectrodes would facilitate long-term neural recording because it would slow the growth of encapsulation tissue, which causes electrodes to separate from the brain tissue.