MgGa layered double hydroxides coating endow magnesium with antibacterial and osteogenic properties for guided-bone regeneration application

For alveolar bone defects, magnesium membrane with the mechanical properties of shielding fibrocyte growth and sustainable release of Mg²⁺ is an excellent choice for guide bone regeneration (GBR) surgery. However, insufficient osteogenesis and bacterial infection have hindered its application. In this study, MgGa-LDH coating was successfully prepared, which delayed the degradation rate of the Mg membranes and greatly reduced the amount of hydrogen evolution. A weakly alkaline microenvironment (pH = 8.5) containing appropriate concentrations of Mg²⁺ and Ga³⁺ was successfully constructed, effectively promoting the adhesion and proliferation of MC3T3-E1 cells. It also upregulated the expression of alkaline phosphatase and collagen, which were conducive to the formation of mineralized nodules, and promoted the osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro. In addition, Ga³⁺ released from the coating and the generated alkaline microenvironment showed good antibacterial properties against S. aureus and E. coli. The MgGa-LDH coating can effectively reduce the degradation rate of Mg membranes and mitigate inflammation. The MgGa-LDH coating modified Mg membrane promoted new bone formation in cranial defect animal models. This bone-promoting Mg²⁺ and Ga³⁺ releasing platform and weak alkaline microenvironment creation system paves the way for the application of Mg membranes in the field of GBR.