Injectable self-healing polysaccharide hydrogel with slow-release b-FGF for adipose tissue regeneration

b-FGF and an autologous adipose tissue suspension were incorporated into the self-healing injectable hydrogel through a Schiff base reaction to crosslink carbohydrazide-modified gelatin (Gel-CDH) and oxidized hyaluronic acid (OHA). • The b-FGF@OHA/Gel-CDH hydrogel demonstrated advantageous mechanical properties, injectability, self-healing ability, microstructural integrity, and biocompatibility. • The bioactive hydrogel with slow release of b-FGF promotes adipogenesis in vitro and in vivo . Soft tissue defects require the application of adipose tissue reconstruction techniques; however, these approaches often face challenges such as low survival rates due to mechanical pressure and inadequate blood supply. This study presents the development of an injectable, self-healing polysaccharide hydrogel designed for the slow release of basic fibroblast growth factor (b-FGF) that utilizes oxidized hyaluronic acid (OHA) and carbohydrazide-modified gelatin (Gel-CDH) as foundational components. The hydrogel is characterized by an optimal pore size, porosity, mechanical properties, and degradation behavior, in addition to excellent biocompatibility, all of which facilitate adipose tissue growth. In vitro experiments revealed that the OHA/Gel-CDH polysaccharide hydrogel significantly enhanced the adipogenic differentiation of adipose-derived stem cells. Furthermore, the implantation of the polysaccharide hydrogel in conjunction with an autologous fat graft suspension into the subcutaneous of the rat dorsal region resulted in improved adipose tissue survival and the regeneration of vascularized adipose tissue. These results suggest that the use of an injectable, self-healing OHA/Gel-CDH polysaccharide hydrogel with slow-released b-FGF in combination with autologous fat grafting is a promising strategy for the repair of soft tissue defects.