<p>This study presents a novel injectable sodium alginate hydrogel designed to enhanc stem cell therapy for endometrial regeneration. Using calcium gluconate as a crosslinking agent, we achieved improved homogeneity and injectability compared to traditional calcium chloride crosslinking. RGD modification further enhanced cell adhesion, proliferation, and differentiation in vitro, creating a bioactive scaffold for umbilical cord mesenchymal stem cells (UCMSCs) delivery. In a mouse model of endometrial injury, intrauterine transplantation of RGD-modified hydrogel encapsulating UCMSCs significantly improved endometrial thickness, reduced fibrosis, enhanced angiogenesis, and increased pregnancy rates compared to both untreated controls and UCMSCs alone. These results suggest that this injectable hydrogel system combined with stem cells holds significant promise for future applications in treating endometrial damage and improving reproductive outcomes in women.</p> Graphical Abstract <p></p>