Fibroin/peptide co-functionalized calcium titanate nanorods improve osteoinductivity of titanium via mimicking osteogenic niche

The surface-inspirable biomaterials have captured extensive attention in simulating microenvironments by mimicking nanoscale architectures and signal molecules in the extracellular matrix (ECM). To activate osteogenic differentiation through biomimetic nanostructures, osteoid-like calcium titanate nanorods (CT) were fabricated via anodization and hydrothermal treatment. SEM, EDS, and XPS were employed to confirm the morphology and chemical composition. The functional fibroin and peptide layers on CT (PFCT) were subsequently applied to provide binding sites and bioactive molecules for osteoblast growth and differentiation. The hydrophilicity obviously increased with the protein layers. PFCT presented enhanced cell viability with pronounced pseudopod extension and continuous proliferation. The osteogenic differentiation analysis revealed that the alkaline phosphatase expression improved in the early stage. The calcium nodes and the collagen secretion were also enhanced. Quantitative polymerase chain reaction assessment indicated that osteogenesis-related markers including ALP, Col1, and Runx2, were up-regulated. The in vitro results demonstrated that fibroin/peptide co-functionalized calcium titanate nanorods were efficient to stimulate osteoblasts and improve cell adhesion, proliferation, and differentiation. Therefore, the nanorods can create an osteogenic niche on titanium implants, which can be a promising modification strategy in bone tissue engineering application.