Human mesenchymal stem cell differentiation on bioactive glass-coated implants

Successful osseointegration of titanium implants remains a major challenge because the ideal bioactive surface coating and its specific influence on stem cell osteogenic differentiation are not yet fully understood. Therefore, it is of interest to evaluate the effect of bioactive glass (BG) coatings on the osteogenic differentiation of human bone marrow mesenchymal stem cells cultured on titanium implant discs. Forty-eight commercially pure titanium discs were divided into four groups (n = 12 each): uncoated control, 45S5 BG-coated, strontium-substituted BG-coated (Sr-BG) and zinc-substituted BG-coated (Zn-BG) and assessed at days 7, 14 and 21 for cell viability, alkaline phosphatase activity, osteocalcin expression, mineralized nodule formation and expression of RUNX2, COL1A1, OCN and OPN. All BG- coated groups demonstrated significantly greater cell viability, ALP activity and mineralized calcium deposition than the uncoated control (p < 0.05), while the Sr-BG group showed the highest RUNX2 and osteocalcin gene expression at day 21 (p < 0.001), followed by the Zn- BG group. Bioactive glass coating, particularly strontium-substituted BG, significantly enhanced osteogenic differentiation of hBMSCs on titanium surfaces and may improve the clinical success of osseointegration.