Osteogenic Microenvironment Restoration around Dental Implants Induced by an Injectable MXene-Based Hydrogel

Peri-implantitis is an excessive inflammatory response induced by complex interactions between the bacteria, host immune system, and tissues around the dental implant. Alveolar bone resorption caused by peri-implantitis is a significant cause of implant failure. However, to restore the osteogenic microenvironment, a multifaceted therapeutic method that simultaneously encompasses anti-inflammatory and tissue regenerative strategies is indispensable. In this study, a temperature-sensitive hydrogel (FMXO) loaded with MXene and MgO was used to develop a multifunctional injectable MXene-based hydrogel. This hydrogel could release MXene and MgO in irregular bone defect areas in situ with no toxicity, either in vitro or in vivo. Our results showed that FMXO effectively inhibited the NF-κB signaling pathway in RAW264.7 cells and simultaneously upregulated the expression of ALP, Runx2, and OCN in bone marrow mesenchymal stromal cells (BMSCs). Therefore, FMXO exerted pharmacological effects on inflammation and bone regeneration. Moreover, we found that FMXO, when exposed to near-infrared (NIR) light, exhibited high efficacy against Porphyromonas gingivalis, Fusobacterium nucleatum, and their plaque microorganisms, which were considered the initiating factors of peri-implantitis. The multifunctionality of FMXO was also confirmed in an immediate peri-implant rat model in vivo, suggesting the great potential for peri-implantitis therapy in the dental clinic.