Effects of strontium amount on the mechanical strength and cell-biological performance of magnesium-strontium phosphate bioceramics for bone regeneration.

Magnesium and strontium are able to enhance osteogenesis and suppress osteoclastic activities simultaneously, and they were nontoxic in wide concentration ranges; these make the magnesium-strontium phosphate bioceramics suitable for treating osteoporotic bone defects. The aim of this study was to investigate the effects of strontium amount on the mechanical strength and cell-biological performance of magnesium-strontium phosphate [MgxSr3-x(PO4)2; 3-x = 0, 0.1, 0.25, 0.5, 0.75, 1] bioceramics, which were sintered at 1100 °C. The results indicated that the magnesium-strontium phosphate bioceramics except Mg2.9Sr0.1(PO4)2 and Mg2.25Sr0.75(PO4)2 bioceramics had considerable compressive strength. The variation in magnesium and strontium contents did not regularly affect the in vitro osteogenic differentiation and osteoclastic activities. The Mg2.75Sr0.25(PO4)2 bioceramic had the most desirable overall performance, as reflected by considerably high compressive strength, enhanced in vitro osteogenesis and inhibited osteoclastic activities. Therefore, the Mg2.75Sr0.25(PO4)2 bioceramic is considered a promising biomaterial for osteoporotic bone regeneration.