Modulating degradation of sodium alginate/bioglass hydrogel for improving tissue infiltration and promoting wound healing

More and more studies have recognized that the nanosized pores of hydrogels are too small for cells to normally grow and newly formed tissue to infiltrate, which impedes tissue regeneration. Recently, hydrogels with macropores and/or controlled degradation attract more and more attention for solving this problem. Sodium alginate/Bioglass (SA/BG) hydrogel, which has been reported to be an injectable and bioactive hydrogel, is also limited to be used as tissue engineering scaffolds due to its nanosized pores. Therefore, in this study, degradation of SA/BG hydrogel was modulated by grafting deferoxamine (DFO) to SA. The functionalized grafted DFO-SA (G-DFO-SA) was used to form G-DFO-SA/BG injectable hydrogel. In vitro degradation experiments proved that, compared to SA/BG hydrogel, G-DFO-SA/BG hydrogel had a faster mass loss and structural disintegration. When the hydrogels were implanted subcutaneously, G-DFO-SA/BG hydrogel possessed a faster degradation and better tissue infiltration as compared to SA/BG hydrogel. In addition, in a rat full-thickness skin defect model, wound healing studies showed that, G-DFO-SA/BG hydrogel significantly accelerated wound healing process by inducing more blood vessels formation. Therefore, G-DFO-SA/BG hydrogel can promote tissue infiltration and stimulate angiogenesis formation, which suggesting a promising application potential in tissue regeneration.