Injectable extracellular matrix hydrogels contribute to native cell infiltration in a rat partial nephrectomy model

Decellularized extracellular matrix (dECM) hydrogels have cytocompatibility, and are currently being investigated for application in soft tissues as a material that promotes native cell infiltration and tissue reconstruction. A dECM hydrogel has broad potential for application in organs with complex structures or various tissue injury models. In this study, we investigated the practical application of a dECM hydrogel by injecting a kidney-derived dECM hydrogel into a rat partial nephrectomy model. The prepared dECM hydrogel was adjustable in viscosity to allow holding at the excision site, and after gelation, had an elastic modulus similar to that of kidney tissue. In addition, the migration of renal epithelial cells and vascular endothelial cells embedded in dECM hydrogels was observed in vitro. Four weeks after injection of the dECM hydrogel to the partial excision site of the kidneys, infiltration of renal tubular constituent cells and native cells with high proliferative activity, as well as angiogenesis, were observed inside the injected areas. This study is the first to show that dECM hydrogels can be applied to the kidney, one of the most complex structural organs and that they can function as a scaffold to induce angiogenesis and infiltration of organ-specific renal tubular constituent cells, providing fundamental insights for further application of dECM hydrogels.