Biomimetic ceramic surfaces produced by thermal spraying nanostructured titania: A coating alternative to hydroxyapatite on orthopedic implants?

There is an ongoing effort to improve the quality and performance of orthopedic implants. Part of this work involves the development of coatings suitable for use in the human body and having properties and bio-performance characteristics better than those of existing materials. The present study focused on developing thermal spray titania coatings engineered to have a bimodal structure consisting of a major fraction of micron scale dimensions within which were dispersed zones of nanostructured material. The coatings were found to exhibit much stronger adhesion to Ti-6Al-4V substrates than conventional hydroxyapatite coatings and to possess excellent crack propagation resistance characteristics. Cell culture studies indicated that human osteoblasts attached and proliferated well on the coating surface. The surface nano-features and nanostructured zones in the coating are believed to play an important role in the improved bonding, mechanical properties and bio-performance.