Injectable self-assembled dual-crosslinked alginate/recombinant collagen-based hydrogel for endometrium regeneration

The disadvantages of mainstream therapies for endometrial injury are difficult to resolve, herein, we suggest an omnibearing improvement strategy by introducing an injectable multifunctional self-assembled dual-crosslinked sodium alginate/recombinant collagen hydrogel. The hydrogel possessed a reversible and dynamic double network based on dynamic covalent bonds and ionic interactions, which also contributed to excellent capability in viscosity and injectability. Moreover, it was also biodegradable with a suitable speed, giving off active ingredients during the degradation process and eventually disappearing completely. In vitro tests exhibited that the hydrogel was biocompatible and able to enhance endometrial stromal cells viability. These features synergistically promoted cell multiplication and maintenance of endometrial hormone homeostasis, which accelerated endometrial matrix regeneration and structural reconstruction after severe injury in vivo. Furthermore, we explored the interrelation between the hydrogel characteristics, endometrial structure, and postoperative uterine recovery, which would benefit deep research on regulation of uterine repair mechanism and optimization of hydrogel materials. The injectable hydrogel could achieve favourable therapeutic efficacy without the need of exogenous hormones or cells, which would be of clinical value in endometrium regeneration.