Silver-Loaded Titania-Based Metal–Organic Frameworks as a Platform for Silver Ion Release for Antibacterial Applications

Conventional Ag-decorated TiO2 coatings suffer from low adsorption capacity and burst release kinetics, limiting long-term antibacterial efficacy and risking cytotoxicity. An entirely different payload release approach can be based on metal–organic frameworks (MOFs), which offer tunable porosity, high surface area, and internal diffusion channels. Here, we report a thermally stabilized Ti-based MOF [NH2-MIL-125(Ti)] functionalized with Ag+ via reactive deposition, enabling high Ag loading (∼14.7 wt %) and sustained release. Annealing at 250 °C enhances aqueous stability, allowing diffusion-governed Ag+ delivery over >48 h, with 77% of the Ag still present in the MOF after a 24 h release. The system exhibits dose-dependent antibacterial activity in powders and comparable efficacy in coatings, with a more gradual release profile. This scalable platform is promising for long-acting coatings, wound interfaces, and implantable materials.