The effects of Ca2SiO4-Ca3(PO4)2 ceramics on adult human mesenchymal stem cell viability, adhesion, proliferation, differentiation and function

Bioceramic samples with osteogenic properties, suitable for use in the regeneration of hard tissue, were synthesized. The materials consisting of alpha-tricalcium phosphate (alpha TCP) and also aTCP doped with either 1.5 wt.% or 3.0 wt.% of dicalcium silicate (C2S) in the system Dicalcium Silicate-Tricalcium Phosphate (C2S-TCP) were obtained by solid state reaction. All materials were composed of a single phase, aTCP in the case of a pure material, or solid solution of C2S in alpha TCP (alpha TCPss) for the doped alpha TCP. Viability, proliferation and in vitro osteoinductive capacity were investigated by seeding, adult mesenchymal stem cells of human origin (ahMSCs) which were CD73(+), CD90(+), CD105(+), CD34(-) and CD45(-) onto the 3 substrates for 30 days. Results show a non-cytotoxic effect after applying an indirect apoptosis test (Annexin V/7-AAD staining), so ahMSCs adhered, spread, proliferated and produced extracellular matrix (Heparan-sulfate proteoglycan (HS) and osteopontin (OP)) on all the ceramics studied. Finally, the cells lost the cluster differentiation marker expression CD73, CD90 y CD105 characteristic of ahMSCs and they showed an osteoblastic phenotype (Alkaline phosphatase activity (ALP), Osteocalcin production (OC), Collagen type I expression (Col-l), and production of mineralization nodules on the extracellular matrix). These observations were more evident in the alpha TCP ceramic doped with 1.5 wt.% C2S, indicating osteoblastic differentiation as a result of the increased concentration of solid solution of C2S in alpha TCP (alpha TCPss). Overall, these results suggest that the ceramics studied are cytocompatible and they are able to induce osteoblastic differentiation of undifferentiated ahMSCs. (C) 2013 Elsevier B.V. All rights reserved.