Towards bioinspired parylene-C coatings of implant surfaces

The external surfaces of an implanted prosthesis must be biocompatible. As the properties of a biological surface vary, often gradually but also abruptly, the implant surface should be endowed with a gradient of surface roughness and wettability for good integration with proteins and cells. We have made free-standing, flexible, fibrous, nano/micro-textured thin films of parylene-C with thickness-controlled surface morphology and hydrophobicity; furthermore, varying degrees of hydrophilicity are displayed after oxygen-plasma treatment. The bioinspired thin films are mechanically robust and have been shown to support both protein binding and cellular attachment as well as growth. By conformally covering an implant surface with patches of these thin films of varying thickness and oxygen-plasma-treatment duration, gradients of protein/cell attachment can be tailored and thus tissue integration can be managed on different parts of the implant surface.