Umbilical cord mesenchymal stem cell spheroids loaded decellularized liver hydrogel rescues liver fibrosis by inhibiting hepatic stellate cells autophagy

Liver fibrosis (LF), driven primarily by activated hepatic stellate cells (aHSCs), progresses to life-threatening end-stage diseases such as cirrhosis, hepatocellular carcinoma. As the only effective treatment, liver transplantation remains limited by donor scarcity. While mesenchymal stem cells (MSCs) exert anti-fibrotic effects via immunomodulation, autophagy regulation, and tissue regeneration, their clinical application is hindered by poor survival, short residence time, and inefficient homing after systemic administration. Recent advances indicate that 3D MSCs spheroids enhance cell viability and paracrine function compared to monodispersed cells. Human umbilical cord MSCs (HUMSCs) are ideal due to low immunogenicity and minimal ethical concerns. Injectable decellularized extracellular matrix (dECM) hydrogels, particularly liver-derived ECM (LdECM), offer a bioactive microenvironment to support cell retention and sustained release.HUMSCs spheroids (HUMSCs sph) were engineered using AggreWell™ plates. An injectable hydrogel was fabricated from decellularized Sprague-Dawley (SD) rat liver scaffolds (LdECM). A novel therapeutic strategy for LF was developed by encapsulating HUMSCs sph within LdECM hydrogels. The structure and characteristics of HUMSCs sph/sus and LdECM were assessed. The efficacy of localized high-density HUMSCs sph delivery was evaluated in a C57BL/6 mouse model of bile duct ligation/carbon tetrachloride (BDL/CCL4)-induced LF, comparing outcomes against equivalent doses of HUMSCs suspension (HUMSCs sus). HSCs autophagy and activation were detected while co-cultured with HUMSCs sph/sus.