Enhanced osteogenic differentiation of human mesenchymal stem cells by flexible β-tcp/pla bone grafts with silicate additive

In recent years, ceramics, polymers, and composites have been used to develop biologically and mechanically suitable bone scaffolds. β-tricalcium phosphate（β-TCP) is a widely used bioceramic in bone tissue engineering. It shows excellent osteoconductivity, osteoinductivity, and good biocompatibility properties, as its chemical composition is similar to the original chemical structure of bone. Herein, we designed β-TCP-PLA composite scaffolds containing two different concentrations of silicate additives. We aimed to investigate the effect of silicate-additive with varying concentrations (0.8% and 1%) on osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) seeded flexible bone grafts. The morphological structure of β-TCP-PLA-based bone grafts was assessed by scanning electron microscopy (SEM) and the tensile strength of grafts was evaluated. The results showed that scaffolds had porous and flexible structures. hMSCs osteogenic differentiation was evaluated with the alkaline phosphatase (ALP) activity and DNA content measurements. Compared with β-TCP-PLA grafts, these designed synthetic flexible bone grafts with 0.8% and 1% silicate-additive significantly promoted hMSCs proliferation and osteogenic differentiation. Moreover, 0.8% silicate-additive β-TCP-PLA grafts showed increased ALP activity. The outcomes of the present study suggest that synthetic flexible bone grafts with silicate-additive might be useful for encouraging the regeneration of bone.