Nanosilver-incorporated halloysite nanotubes/gelatin methacrylate hybrid hydrogel with osteoimmunomodulatory and antibacterial activity for bone regeneration

After a biomaterial is implanted in a bone defect area, the immune response and bacterial infection affect the success of bone regeneration. In this study, we describe the development of a promising therapeutic approach to accelerate bone regeneration via combining osteoimmunomodulatory and antibacterial activities. Herein, we fabricated a nanosilver/halloysite nanotubes/gelatin methacrylate (nAg/HNTs/GelMA) hybrid hydrogel and evaluated its osteoimmunomodulatory and antibacterial properties in vitro and in vivo. The nAg/HNTs/GelMA hybrid hydrogel had good biocompatibility with human periodontal ligament stem cells (hPDLSCs) and macrophages. Moreover, the nAg/HNTs/GelMA hybrid hydrogel modulated inflammatory cytokines secreted by macrophages and enhanced the osteogenic differentiation of hPDLSCs in an inflammatory environment. In addition, nAg/HNTs/GelMA hybrid hydrogel inhibited the growth of Gram-positive and Gram-negative bacteria in vitro and in vivo. Compared with HNTs/GelMA hydrogel, the nAg/HNTs/GelMA hybrid hydrogel better modulated the osteoimmune microenvironment and eliminated bacterial infection. Thus, this hybrid hydrogel combining osteoimmunomodulatory with antibacterial activities is a promising biomaterial for bone regeneration in defect areas.