Composite Calcium Phosphate/Titania Scaffolds in Bone Tissue Engineering

Titanium and its alloys have been extensively used as implantation materials due to their favorable properties such as lower modulus, good tensile strength, excellent biocompatibility, and enhanced corrosion resistance. However, their intrinsic bioinertness generally prevents a direct bond with the bone on the surface especially at an early stage of implantation. In recent years, bioactive scaffolds for bone regeneration are progressively replacing bioinert prostheses in orthopedic, maxillofacial, and neurosurgery fields. Given the need of enhanced mechanical strength, several combinations of bioactive and reinforcing phases have been studied, but still no convincing solutions have been found so far. In this context, titanium oxides are light and high-resistance bioactive materials widely employed in dental and bone application due to their capacity of forming strong bonds with bone tissue via the formation of a tightly bound apatite layer on their surface. The addition of titania particles to hydroxyapatite has attracted considerable attention based on the assumption that resulting materials can enhance osteoblast adhesion and promote cell growth while also providing high strength and fracture toughness in the final composite material, thus being adequate for load-bearing applications.