Abstract: Disclosed herein is a material that may be useful as a coating for optical slides and medical implants. The material may aid or restrict grown of cells on a coating of the composite material. As such, there is provided a composite material having a substrate on the surface of which a coating layer of an amorphous metal oxide is formed. The metal oxide may be one or more of Ag2O, ZnO, ZrO2, TiO2, CuO, and Y2O3 and the coating layer may be from 5 to 100 nm thick and have a root mean square roughness of the coating surface is from 0.1 to 0.7 nm.