3D-Printed Multidimensional Bionic Mg-MC/PLGA Composite for Tailored Repair of Segmental Long Bone Defects

The management of long bone segmental defects represents a critical challenge in orthopedic medicine. This study focuses on developing an innovative bone repair material to overcome the inherent limitations of existing solutions. The material is synthesized by incorporating magnesium into mineralized collagen to produce Mg-MC bone powder, which is then combined with polylactic acid-hydroxyglycolic acid copolymer (PLGA). Using advanced 3D printing and femtosecond laser techniques, Mg-MC/PLGA scaffolds with varying magnesium concentrations (0%, 5%, 10%, 20%) are fabricated and characterized. In vitro studies demonstrate that the 5% Mg-MC/PLGA scaffold exhibits superior cytocompatibility, cellular proliferation, migration, angiogenesis, and osteogenic activity, supported by elevated expression of osteogenic markers. In vivo experiments in a rabbit model confirm the efficacy of the 5% Mg²⁺-doped scaffold in promoting bone regeneration, with significant improvements in bone volume, trabecular thickness, and biomechanical strength. These findings highlight the potential of the 5% Mg-MC/PLGA scaffold as a promising solution for the clinical treatment of bone defects.