Microstructure, mechanical, biodegradable, antitumor and osteogenic performances of as-cast MgGa alloys for postoperative bone tumor repair.

As a biodegradable material, magnesium‑gallium (Mg-xGa) alloy has exhibited outstanding antibacterial properties, however, its potential application in postoperative bone tumor repair still necessitates the validation of its antitumor function. In this study, Mg-xGa alloys (x = 0.5, 1.0, and 2.0 wt%) were successfully fabricated via conventional melting. The microstructure, biodegradation behavior, and tensile properties of the alloys were systematically characterized, followed by a comprehensive evaluation of their in vitro and in vivo biocompatibility and antitumor activity. Results demonstrated a uniform distribution of Ga as a solid solution in the Mg matrix, with no detectable second phases formed in the Mg-xGa alloys. Among the alloys, the Mg-2.0Ga alloy displayed optimal comprehensive tensile properties, coupled with a degradation rate of 0.134 mm/year. The Mg-xGa alloys effectively inhibited the proliferation and migration of U2OS and 143B bone tumor cells. This was associated with mitochondrial membrane potential depression, leading to the induction of apoptosis. In addition, the alloys exhibited favorable biocompatibility and osteogenic properties in vitro when co-cultured with MC3T3-E1 osteoblasts. Furthermore, in subcutaneous tumor models, they exhibited excellent antitumor activity and biocompatibility without significant systemic toxicity observed. In summary, the incorporation of an appropriate amount of Ga into Mg effectively inhibits tumorigenic activity in bone tumor cells while maintaining normal cellular functions in healthy cells. This Mg-xGa alloy exhibits broad application prospects in both bone tissue engineering and bone tumor therapy, warranting further exploration of their clinical value.