Surface-adhesive layer-by-layer assembled hydroxyapatite for bioinspired functionalization of titanium surfaces

Abstract

A novel and versatile fabrication route for titanium-based biocomposites has been realized by mussel adhesion chemistry through layer-by-layer assembly of polydopamine (PDOA) and hydroxyapatite (HA). The assembly process was monitored by XPS analysis and weight shifts. The chemical structure and the surface morphologies of the assembly layers were analyzed by FTIR, XPS and SEM, respectively. It was found that the assembly between PDOA and HA can be repeated indefinitely, and that a continued growth of this multilayer is possible. The as-prepared hybrid biocomposite materials present a rough surface, and such a structure is beneficial for bone cell adhesion. Primary cell proliferation experiments indicated that PDOA–HA-modified Ti substrates exhibit a good bioactivity. The hybrid assembly layers displayed an outstanding adhesion stability, which suggests that PDOA can be employed as an on-demand robust glue for creating functional biomaterials. These new materials can find widespread use in the field of orthopedic and dental implants due to their excellent mechanical properties and biocompatibility.