Improving osteogenesis of calcium phosphate bone cement by incorporating with manganese doped β-tricalcium phosphate

Lack of osteogenic capacity limits the bone repair effect of calcium phosphate cement (CPC). In present work, bivalent manganese ion (Mn²⁺) doped β-tricalcium phosphate (Mn-TCP) was incorporated into CPC to enhance its osteogenic ability. The incorporation of Mn-TCP promoted the hydration reaction of CPC. The presence of Mn²⁺ made the hydration products finer. When adding 10 wt% Mn-TCP in CPC (Mn-CPC-1), the setting time of CPC was shortened, whereas the strength and injectability were not changed. Mouse Bone marrow mesenchymal stem cells (mBMSCs) on Mn-CPC-1 and CPC with 20 wt% Mn-TCP (Mn-CPC-2) presented better adhesion and spreading behaviors. Besides, Mn-CPC-1 promoted the gene levels of ALP, Col-I and OC while Mn-CPC-2 promoted the gene levels of Runx2 and OC. Cellular behaviors were related to two points: one was the increase of adsorption capacity of proteins (e.g. BSA) after changing the surface properties of bone cements; and the other was the biological role of Mn²⁺ released from CPC in osteogenesis. All the results indicated that CPC incorporated with 10 wt% Mn-TCP has good osteogenesis and proper physicochemical properties, which will be a prospective biomaterial applying in the area of bone regeneration.