Modified Titanium Implants Satisfy the Demands of Diabetic Osseointegration via Sequential Regulation of Macrophages and Mesenchymal Stem Cells

The application of titanium (Ti) implants for patients with diabetes mellitus (DM) is still facing a significant challenge due to obstacles such as hyperglycemia, reactive oxygen species (ROS), and chronic inflammation, which hinders osseointegration. To address this issue, a Ti implant with dual functions of regulating polarization of macrophages and facilitating osseointergration is developed via hydrothermal reaction and hydrogel coating. The reactive oxygen species (ROS) and glucose (Glu) responsive hydrogel coating can locally deliver adenosine (ADO) in the early stage of implantation. The controlled release of ADO regulated the phenotype of macrophages, restored oxidative balance, and enhanced mitochondrial function during the early stages of implantation. Subsequently, strontium (Sr) ions will be released to promote osteogenic differentiation and proliferation of mesenchymal stem cells (MSCs), as the hydrogel coating degraded. It eventually leads to bone reconstruction during the late stages, aligning with the biological cascade of bone healing. The modified Ti implants showed effective osteogenesis for bone defects in DM patients, shedding light on the design and biological mechanisms of surface modification. This research offers promising potential for improving the treatment of bone-related complications in diabetic patients.