Fabrication of nanocrystalline magnesium phosphate-based composite bioceramics using magnesium-containing phosphate glass as sintering additives

Abstract

Magnesium-rich microenvironment is beneficial to both osteogenic and proangiogenic activities. To construct magnesium-rich microenvironment, the magnesium phosphate bioceramics could not be sintered at high temperatures, leading to low mechanical strength. In this study, magnesium phosphate-based composite (AMP/MPG) bioceramics were fabricated at low sintering temperatures (650 and 800 °C) using amorphous magnesium phosphate (AMP) and magnesium-containing phosphate glass (MPG) powders as starting materials. In the sintering of AMP/MPG, the MPG crystallized and reacted with AMP to form new phases. The AMP/MPG showed nanocrystals and pronouncedly higher compressive strength, in contrast with the bioceramics prepared from crystalline magnesium phosphate powders. The AMP/MPG continuously released high concentrations of magnesium ions, which accounted for the remarkably enhanced cell proliferation, osteogenic and angiogenic activities. The AMP/MPG bioceramics with high mechanical strength, osteostimulative and proangiogenic capacity were considered promising biomaterials to effectively regenerate the critical-size bone defects.