An injectable hydrogel derived from small intestine submucosa as a stem cell carrier.

Small intestine submucosa (SIS) is used as an attractive biomaterial in the field of regenerative medicine because it possesses numerous bioactive factors such as cell adhesion proteins, growth factors, and glycosaminoglycans. In most cases, SIS has been used as sheet and sponge-like forms. The goal of present study was to prepare an injectable SIS hydrogel and to examine the feasibility as an in vivo stem cell carrier of injectable SIS hydrogel form. The rat muscle-derived stem cells (rMDSCs) were simply incorporated into SIS hydrogel by mixing. The SIS hydrogel showed a porous microstructure. In vitro cytotoxicity test, attachment, and proliferation of rMDSCs on the SIS hydrogel were higher than those on tissue culture dishes. Then rMDSCs-loaded SIS hydrogel was subcutaneously injected into rats. The in vivo formed rMDSCs-loaded SIS hydrogel implant induced the ingrowth of new vessels and cell proliferation. In addition, SIS and rMDSCs suppressed macrophage-mediated inflammation. In conclusion, we confirmed that injectable SIS hydrogel could serve as a minimally invasive stem cell carrier. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1544-1550, 2016.