Ultrasound‐Triggered Mg2+ Blasting Release Hydrogel Microspheres for Promoting Bone Reconstruction

Abstract Mg 2+ (Magnesium ion) can affect bone tissue metabolism by regulating related signaling pathways in bone metabolism. However, how to realize precise controlled release of Mg 2+ in bone regeneration treatment still presents a challenge. Herein, for the first time, the GelMA‐BP (Gelatin Methacryloyl‐Bisphosphonate) and the composite nano‐bubble system are fused to construct the Mg 2+ blasting controlled‐release hydrogel microspheres, the stability of the nano‐bubbles in the microspheres is enhanced through metal coordination complexation, and the burst of the nano‐bubbles is controlled by using ultrasonic cavitation to achieve the precise controlled release of Mg 2+ , ultimately effectively promoting bone reconstruction. First, GelMA‐BP composite is prepared by Schiff base reaction. Second, the nanobubble BP (Bisphosphonate) system is constructed, and Mg 2+ is combined with the ligand coordination to prepare the composite nanobubble system. Thirdly, through Mg 2+ co‐coordination, the ultrasound‐triggered Mg 2+ blasting controlled release microspheres were prepared to achieve bone repair. Overall, this innovative strategy effectively solves the problem of accurate controlled release of Mg 2+ , and finally effectively activates in situ bone tissue regeneration.