Immunomodulatory Hydrogel Coating with SeNPs and Lithium Silicate Synergistically Promotes Osseointegration and Prevents Infection on Titanium Implants

Effective osseointegration of implants remains a major challenge in biomaterials and regenerative medicine. In this context, restoring the disrupted microenvironment between the implant and bone tissue is critical, as it is primarily influenced by excessive ROS, infections, immune inflammatory reactions, and imbalances in bone homeostasis. To address these challenges, a composite hydrogel coating composed of lithium disilicate (Lap) and selenium nanoparticles (SeNPs) is developed, fabricated through the crosslinking of methacrylated carboxymethyl chitosan (CMCSMA) and methacrylated gelatin hydrogel (GelMA). The resulting Lap-CMCSMA/GelMA@SeNPs hydrogel exhibits excellent biocompatibility and forms a robust adhesion to titanium (Ti) implants. In vitro studies demonstrate that titanium substrates coated with Lap-CMCSMA/GelMA@SeNPs could efficiently neutralize excessive intracellular ROS. Moreover, the coating displays potent anti-inflammatory properties by promoting a shift in macrophage polarization toward the M2 phenotype. Additionally, the integration of SeNPs markedly improves the antibacterial performance of Lap, showing strong inhibitory effects against common pathogens such as E. coli and S. aureus. Both in vitro and in vivo evaluations show superior osteogenic activity of the Lap-CMCSMA/GelMA@SeNPs-coated implants, largely attributed to the inherent osteogenic potential of Lap. The findings indicate that titanium implants functionalized with the Lap-CMCSMA/GelMA@SeNPs hydrogel may provide an innovative therapeutic strategy for mitigating peri-implant microenvironment imbalances post-surgery.