Response of human bone marrow stromal cells to a resorbable P2O5–SiO2–CaO–MgO–Na2O–K2O phosphate glass ceramic for tissue engineering applications

This work focuses on the synthesis and characterization of a novel bioresorbable glass ceramic phosphate-based material (GC-ICEL). More specifically, its solubility in different aqueous media (water, Tris–HCl and acellular simulated body fluid) and the response of human stromal cells cultured on it were investigated. X-ray diffraction analysis showed the presence of two crystalline phases identified as Na2Mg(PO4)3 and Ca2P2O7 and dissolution tests highlighted a preferential dissolution of the Na2Mg(PO4)3 phase and of the residual amorphous phase in all the chosen media. Soaking tests in simulated body fluid showed precipitation of a hydroxyapatite layer, demonstrating the bioactivity of GC-ICEL, which is partially due to the reported bioactivity of Ca2P2O7. The effect of GC-ICEL on adhesion, proliferation and osteoblastic gene expression of human bone marrow-derived stromal cells was also studied. Combining molecular and biochemical analyses, it was found that bone marrow cell differentiation was stimulated over proliferation on GC-ICEL. Moreover, the expression of bone-related genes in cells cultured on GC-ICEL confirmed the bioactivity of this phosphate-based glass ceramic, which might have a stimulatory effect on osteogenesis.