Enhancing osteogenesis and mandibular defect repair with magnesium-modified acellular bovine bone matrix

An acellular bovine bone matrix modified to release Magnesium ions (Mg²⁺) (ABBM-Mg) was prepared and evaluated for its potential in osteogenesis and mandibular defect repair. Mg²⁺ was incorporated into ABBM using an ion exchange method. The microstructure and mechanical properties of both ABBM and ABBM-Mg were analyzed using SEM and a biomechanical testing machine. Cytocompatibility, cell adhesion, and osteogenic differentiation were assessed using various methods including CCK-8, Live/Dead staining, SEM, ALP staining, and qPCR analysis in MC3T3-E1 cells. Additionally, a mandibular defect model in rats was established. The bone defect repair outcomes were evaluated using Micro-CT, histological HE staining, and Masson staining. The study showed that mineralization containing magnesium was redeposited on the surface of the three-dimensional porous ABBM, and the ABBM-Mg scaffold promoted cell proliferation and osteogenic differentiation compared to the ABBM scaffold. In the rat mandibular defect model, the ABBM-Mg scaffold demonstrated superior bone repair ability. This study successfully incorporated Mg²⁺ into ABBM without significantly affecting its microstructure and compressive strength. Furthermore, ABBM-Mg showed sustained release of Mg²⁺ which enhanced cell proliferation, adhesion, and osteogenic differentiation in vitro, and promoted mandibular defect healing in rats. This research opens up new possibilities for the clinical application of functionalized acellular bone matrix.