Bioactive-glass ceramic with two crystalline phases (BioS-2P) for bone tissue engineering

We aimed to evaluate the in vitro osteogenic and osteoinductive potentials of BioS-2P and its ability to promote in vivo bone repair. To investigate osteogenic potential, UMR-106 osteoblastic cells were cultured on BioS-2P and Bioglass 45S5 discs in osteogenic medium. The osteoinductive potential was evaluated using mesenchymal stem cells (MSCs) cultured on BioS-2P, Bioglass 45S5 and polystyrene in non-osteogenic medium. Rat bone calvarial defects were implanted with BioS-2P scaffolds alone or seeded with MSCs. UMR-106 proliferation was similar for both materials, while alkaline phosphatase (ALP) activity and mineralization were higher for BioS-2P. Bone sialoprotein (BSP), RUNX2 and osteopontin (OPN) gene expression and BSP, OPN, ALP and RUNX2 protein expression were higher on BioS-2P. For MSCs, ALP activity was higher on Bioglass 45S5 than on BioS-2P and was lower on polystyrene. All genes were highly expressed on bioactive glasses compared to polystyrene. BioS-2P scaffolds promoted in vivo bone formation without differences in the morphometric parameters at 4, 8 and 12 weeks. After 8 weeks, the combination of BioS-2P with MSCs did not increase the quantity of new bone compared to the BioS-2P alone. To stimulate osteoblast activity, drive MSC differentiation and promote bone formation, BioS-2P is a good choice as a scaffold for bone tissue engineering.