Effect of the secretome derived from mesenchymal stem cells overexpressing BMP-9 on osteoblasts grown on titanium with nanotopography

Abstract

The bone morphogenetic protein 9 (BMP-9) exhibits high osseoinductive capacity. We have demonstrated that Ti with nanotopography (Ti-Nano) generated by treatment with H2SO4 and H2O2 favors osteoblast differentiation by modulating several cell signaling pathways and that mesenchymal stem cells grown on this nanotopography are more responsive to BMP-9. In this context, the aim of this study is to evaluate the effect of the secretome derived from MSCs overexpressing BMP-9 (MSCsBMP-9) on osteoblasts grown on Ti-Nano. Osteoblasts derived from calvariae of newborn rats will be cultured on Ti-Nano and Ti-Control in conditioned media (secretomes) by either MSCsBMP-9 (BMP-9-CM) or MSCs non-overexpressing BMP-9 (VPR-CM). Osteoblasts will be cultured under osteogenic conditions for up to 10 days to evaluate: gene expression of Runx2, osteocalcin (Oc), osteopontin (Opn) and bone sialoprotein (Bsp) by real-time PCR, protein expression of RUNX2 and alkaline phosphatase (ALP) by western blot, and ALP activity by fast red detection. The numerical data will be submitted to the normal distribution test to select the adequate statistical analysis and the level of significance will be set at 5%. The development of this project could contribute to the understanding of the cellular events that regulate osseointegration and development of new therapies in the implantology field.