Enzymatic process for the preparation of bioactive, osteoblast-stimulating surfaces and using

A method for producing bioactive surfaces by enzymatic modification of molecules or molecular aggregates, particularly collagen, on surfaces of glass, metals, metal oxides, plastics, biopolymers or other materials with amorphous silicon dioxide (silica), or silicones in the cell culture, tissue engineering, or in medical implants wherein a polypeptide is used for the enzymatic modification comprising a silicatein or silicatein-α- β domain. The inventive method leads to a support growth, the activity and / or mineralization of cells / cell cultures.