Dynamic and photodegradable dextran/gelatin hydrogel niche crosslinked with disulfide bonds: Promoting growth and release of stem cells.

Due to the utilization of well-defined artificial niches, stem cell culture in a three-dimensional hydrogel matrix has been a promising method for obtaining sufficient seed cells. Although various hydrogels can support desirable cell proliferation, establishing a normalized hydrogel that adequately mimics the extracellular matrix (ECM), maintains stemness and allows for controlled release of stem cells remains a significant challenge. Herein, we report a hydrogel composed of sulfobetaine-modified dextran and gelatin to maintain stemness and enable the rapid release of adipose-derived stem cells (ADSCs). Dextran can effectively maintain multipotent phenotype of ADSCs by grafting zwitterionic groups. Gelatin can significantly improve the proliferation of ADSCs. The hydrogel network they form effectively mimics the ECM microenvironment, providing an advantage when used as a three-dimensional niche to promote cell proliferation. Most importantly, the disulfide-crosslinked hydrogels show specific photodegradation capability, which precisely enables the system to achieve controlled release and efficient harvest of ADSCs. The cell viability (90 %) and harvest ratio (64 %) were well maintained by light degradation compared with GSH and collagenase degradation. Overall, this study offers a universal stem cell niche based on photodegradable hydrogel that shows great promise in the field of ADSCs proliferation and harvest.