Target-Engineered Liposomes Decorated with Nanozymes Alleviate Liver Fibrosis by Remodeling the Liver Microenvironment

Liver fibrosis is a pathological repair response that occurs after sustained liver damage, and prompt intervention is necessary to prevent liver fibrosis from developing into a potentially life-threatening condition. In long-term liver injury, damaged hepatocytes produce excessive amounts of reactive oxygen species (ROS), which activate hepatic stellate cells (HSCs). This activation leads to excessive accumulation of extracellular matrix proteins in liver tissue. Additionally, liver macrophages contribute to the inflammatory microenvironment in the hepatic fibrotic process, exacerbating liver fibrosis through ROS production and the secretion of pro-inflammatory factors. To address the dysregulation of the hepatic microenvironment associated with liver fibrosis, we developed cerium oxide nanozymes using hyaluronic acid (HA) as a template and decorated them on the surface of liposomes loaded with oleanolic acid (OA). We named this prepared and obtained target-engineered liposome HCOL. The inherent superoxide dismutase (SOD) and catalase (CAT) activities of HCOL enabled it to effectively scavenge ROS in HSCs and alleviate the hypoxic conditions characteristic of fibrotic livers. Furthermore, HCOL reduced the concentrations of ROS in macrophages, promoting a shift in macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. This transition increased the production of the anti-inflammatory cytokine interleukin 10 (IL-10), which contributed to the mitigation of the inflammatory microenvironment. Consequently, this therapeutic approach proves effective in decelerating the advancement of liver fibrosis.