Functionalization of titanium enhances osteoblasts differentiation

Titanium modifications have demonstrated to provide more suitable strategies for implant osseointegration. This investigation evaluated the effect of alkalinization and functionalization of titanium discs with collagen type I (polished or alkali-treated) on the response of osteoblasts. Materials and Methods Titanium discs were manually polished and subjected to alkalinization with NaOH at 5mol/L for 24 hours at 60 o C, followed by determination of surface topography and roughness. Then, they were submitted to functionalization wth collagen type I (1 mg/mL) for 4 hours at 37 o C, followed by osteoblasts seeding (SaOs-2). After 7 days, cell adhesion onto each substrate was evaluated (n=3) as also cell viability (n=6), alkaline phosphatase (ALP) activity (n=6) and gene expression of osteogenic markers (n=6). Titanium surfaces were analyzed by Fourier transform infrared spectroscopy/FTIR (n=3). Data of surface roughness, viability, ALP activity and gene expression were also analyzed by ANOVA two-way and Tukey tests (alpha=0.05), while data on cell adhesion and FTIR were qualitatively evaluated. Results All parameters were increased for the titanium surface subjected to alkalinization and the combination of the two protocols (alkalinization and functionalization with collagen type I) promoted the better results, with higher cell adhesion, viability, ALP activity and gene expression. FTIR demonstrated the main chemical groups of collagen and hydroxyl. The alkalinization of titanium surfaces with NaOH and the functionalization of these surfaces with collagen were effective strategies on stimulating osteoblasts response. The combination of both demonstrated to be the best conditions to cells response.