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

Abstract

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 [Mg_xSr_3-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 Mg_2.9Sr_0.1(PO₄)₂ and Mg_2.25Sr_0.75(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 Mg_2.75Sr_0.25(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 Mg_2.75Sr_0.25(PO₄)₂ bioceramic is considered a promising biomaterial for osteoporotic bone regeneration.

Keywords: Bioceramic; Bone regeneration; Cell response; Magnesium; Strontium.