In Vitro Human Osteoblast Responses to Titanium Oxide-Based Surfaces with Varying Topology and Composition

Surface characteristics are important design considerations for implant materials, as they affect cellular responses. This study examines the effect of variations in the topology and composition of oxidised titanium surfaces on human osteoblast behaviour. Plasma Electrolytic Oxidation (PEO) of Ti‑6Al‑4V alloy produced five oxide surfaces possessing varying surface roughness, morphology and composition. X-ray diffraction, XPS, optical profilometry and contact angle measurement were performed to characterise the surfaces, and human foetal osteoblasts were cultured on them in vitro. The AlamarBlue assay, SEM imaging and an alkaline phosphatase activity assay were used to examine osteoblast proliferation, morphology and differentiation. The effects of oxides contained in the processed surfaces (including rutile, anatase, aluminium oxide and aluminium titanate) were examined individually, by binding them in powder form to produce surfaces with similar morphology, but different chemistry. The responses of the cells to different topological and chemical environments are discussed, providing information for future implant material design.