Synthesis, characterization and biological performance of a calcium titanium oxide film prepared by sol-gel/dip...

In this study, coatings based on calcium titanate (CT) were applied onto titanium substrates using sol-gel process combined with dip-coating. In addition to physical and chemical characterization, we evaluated the impact of this surface modification on the expression of key genes involved in cell adhesion, extracellular matrix (ECM) remodeling, and early osteogenic commitment in pre-osteoblasts (MC3t3-E1, Subclone 4). X-ray diffraction (XRD) confirmed the presence of cubic alpha-calcium titanate (CaTiO₃) strongly bonded to the titanium surface. Although the coating reduced surface roughness, high dipping speeds induced the formation of thicker layers with microcracks due to thermal expansion mismatches. Increased dipping speeds, however, improved surface wettability. Electrochemical analysis revealed enhanced corrosion behavior, attributed to the formation of a stable oxide layer. Biological assays (MTT and crystal violet) confirmed the absence of cytotoxic effects in both direct and indirect contact conditions. Gene expression analysis showed significant upregulation of Itgb1, Fak, Col1a1, and Runx2 in cells cultured with conditioned media from CT-coated surfaces, indicating enhanced integrin-mediated adhesion, ECM deposition, and early osteogenic differentiation. These molecular responses were accompanied by cytoskeletal remodeling, evidenced by increased phosphorylation of cofilin, suggesting enhanced actin filament stabilization. Collectively, sol-gel CT-based layers exhibit beneficial properties as surface coatings and promote a favorable microenvironment for cell adhesion, matrix remodeling, and osteogenic signaling, without inducing cytotoxicity, underscoring their potential for biomedical applications.