EGCG-Modified Bioactive Core-Shell Fibers Modulate Oxidative Stress to Synergistically Promote Vascularized Bone Regeneration

Oxidative stress induced by reactive oxygen species (ROS) can adversely affect tissue repair, whereas endowing biomaterials with antioxidant activity can improve the in vivo microenvironment, thereby promoting angiogenesis and osteogenesis. Accordingly, this study utilized epigallocatechin-3-gallate (EGCG), a material known for its reducing properties, oxidative self-polymerization capability, and strong binding characteristics, to modify a bioactive core-shell fibrous membrane (10RP-PG). Compared to the 10RP-PG fibrous membrane, the EGCG-modified fibrous membrane (E/10RP-PG) exhibited superior hydrophilicity, excellent cell adhesion, and compatibility. Moreover, the EGCG-modified fibrous membrane can effectively scavenge free radicals, ameliorate the local microenvironment, and foster angiogenesis (enhancing the expression of angiogenic genes in human umbilical vein endothelial cells (HUVECs) by 1.58 times and promoting vascular generation area upon subcutaneous implantation by 4.47 times). The enhancement of angiogenic activity of the E/10RP-PG fibrous membrane further promoted cartilage degeneration and absorption, as well as new bone formation, thus facilitating the repair of bone defects. This study provides a new strategy for promoting bone defect repair through the surface modification of biomaterials with an antioxidant agent, and the fabricated E/10RP-PG fibrous membranes show promise for guiding vascularized bone regeneration.