Analytical characterization of collagen- and/or hydroxyapatite-modified polypyrrole films electrosynthesized on Ti-substrates for the development of new bioactive surfaces

The design and development of new bioactive surfaces on titanium-based materials employed in orthopedic implants is described. The new biosurfaces consist of thin polypyrrole films, directly grown on implant materials and modified by the inclusion of hydroxyapatite and/or collagen during the polymer electrodeposition step. The experimental procedure has been optimized in terms of loading and distribution of the bioactive components. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) investigations have been performed in order to control the effectiveness of film modifications. In particular, XPS has been used to check the presence of biocompounds in the surface and sub-surface region of the polymer film, which is a critical requisite for a positive interface interaction between the biomaterial and the surrounding tissue.