Bioactive Hydrogel-Interface-Modified Porous Titanium Alloy Scaffolds for Enhancing Osseointegration

The inherent bioinertness of titanium alloy presents significant challenges for implants, including poor cell adhesion, restricted proliferation, and differentiation, ultimately hindering efficient osseointegration. To address this limitation, this study introduced a magnesium-incorporated gelatin-based macroporous hydrogel (Gelatin-Mg) bioactive interface. This hydrogel modified the surface of porous titanium alloy scaffolds, enhancing osseointegration through a dual mechanism: (1) promoting cell adhesion and proliferation on the scaffold surface and (2) synergistically leveraging magnesium ions to boost osteogenic and angiogenic capabilities. These combined actions culminated in the enhanced ingrowth of new bone tissue within the titanium scaffold, enabling effective osseointegration. The bioactive hydrogel interface demonstrated suitable mechanical properties, sustained magnesium ion release kinetics, and excellent biocompatibility. It significantly promoted both osteogenic and angiogenic performance in in vitro cell assays. In rat bone defect models, compared with unmodified scaffolds, scaffolds modified with the Gelatin-Mg bioactive interface exhibited superior osseointegration efficacy. Therefore, this bioactive hydrogel interface could provide a robust material platform for achieving precise and effective osseointegration, offering significant potential for improving fracture healing outcomes.