disclosed is nanocoupling of a polymer onto a surface of a metal substrate for improving coating adhesion of the polymer on the metal substrate , and in vivo stability and durability of the polymer . in accordance with the present invention , the polymers can be grafted via a chemical bonding on the surface of the metal substrate by the nanocoupling , by which adhesion , biocompatibility and durability of a polymer - coated layer which is to be formed later on the metal substrate were remarkably improved ; therefore , the nanocoupling according to the present invention can be applied to surface modification of a metal implant , such as stents , mechanical valves , and an articular , a spinal , a dental and an orthopedic implants .