Magnesium and gallium-coloaded microspheres accelerate bone repair via osteogenesis and antibiosis

Bone defects have serious economic and clinical impacts; however, despite improvements in bone defect management, the range of clinical outcomes remains limited. A variety of biomaterials have been used to treat complex bone defects. However, final bone repair outcomes may be adversely affected by poor osteogenic capacity and risk of infection. Consequently, therapeutic methods are required that reduce bacterial contamination and increase the use of osteogenic biomaterials. Herein, we report the preparation of poly(lactic acid-coglycolic acid) (PLGA) microspheres coloaded with magnesium (Mg²⁺) and gallium (Ga³⁺) ions (Mg-Ga@PLGA), which can fill irregular bone defects and show good biosafety. During in vitro testing, Mg-Ga@PLGA not only showed a synergistic effect on promoting osteogenic differentiation but also inhibited osteoclastic differentiation. Moreover, we found that Mg-Ga@PLGA demonstrated an antibacterial effect. During in vivo testing, Mg-Ga@PLGA exhibited strong in situ osteogenic ability. In conclusion, Mg-Ga@PLGA has good potential for treating bone defects at risk of infection.