A biomaterial surface’s chemical and physical properties influence bone marrow stromal cells. They undergo a rapid change in cell shape to assume a columnar morphology typical of a secretory osteoblast when grown on titanium (Ti) and Ti alloy surfaces, such as titanium-aluminum-vanadium, with specific topographies that mimic the microscale, mesoscale, and nanoscale features of an osteoclast resorption pit.
These cells express osteoblast-like markers such as osteocalcin and osteopontin, and they release osteogenesis-related substances such as bone morphogenetic protein 2, vascular endothelial growth factor, and neurotrophic semaphorins. The route entails a change in integrin expression from α5β1 to α2β1, as well as signaling by Wnt5a rather than Wnt3a. Conditioned medium from these cultures may induce vasculogenesis in human endothelial cells and osteoblastic differentiation in bone marrow stromal cells that are not grown on the biomimetic substrate, implying that the surface may enhance osteogenesis in vivo via comparable processes.
In vivo studies employing a number of animal models demonstrated that implants with biomimetic surfaces had better osseointegration than Ti implants with smooth surfaces, as do meta-analyses evaluating the clinical efficacy of implant surface topographies.