High mobility group box 1-immobilized nanofibrous scaffold enhances vascularization, osteogenesis and stem cell...

Most tissue engineered bone scaffolds are limited by insufficient vascularization. In this study, a high mobility group box 1 (HMGB1)-immobilized material for in situ tissue engineering was prepared to facilitate bone regeneration. The HMGB1-immobilized scaffold accelerated the adhesion and osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro. Subcutaneous implantation and rat calvarial defect repair experiments proved that the HMGB1-immobilized scaffold induced vascularization and enhanced expression of osteocalcin in vivo. MSCs were recruited into the scaffold, which might due to the high expression of stromal cell-derived factor-1α. The bone repair efficiency of the HMGB1-immobilized scaffold was significantly superior to and faster than that of the poly-l-lactide/polycaprolactone nanofibrous scaffold. This research demonstrated the feasibility of using only one pro-inflammatory cytokine HMGB1 as a 'trigger' signal in bone tissue engineering to simultaneously realize multiple functions, including enhancing vascularization, inducing osteogenesis and recruiting stem cells. Consequently, the bone regeneration process was accelerated. The results are of great significance for preparing a new type of scaffold that can promote bone repair in multiple aspects by mimicking a natural manner.