Carbon dot nanozymes as free radical scavengers for the management of hepatic ischemia-reperfusion injury by regulating the liver inflammatory network and inhibiting apoptosis

BACKGROUND: Hepatic ischemia-reperfusion injury (HIRI) is a pathophysiological process during liver transplantation, characterized by insufficient oxygen supply and subsequent restoration of blood flow leading to an overproduction of reactive oxygen species (ROS), which in turn activates the inflammatory response and leads to cellular damage. Therefore, reducing excess ROS production in the hepatic microenvironment would provide an effective way to mitigate oxidative stress injury and apoptosis during HIRI. Nanozymes with outstanding free radical scavenging activities have aroused great interest and enthusiasm in oxidative stress treatment. RESULTS: We previously demonstrated that carbon-dots (C-dots) nanozymes with SOD-like activity could serve as free radical scavengers. Herein, we proposed that C-dots could protect the liver from ROS-mediated inflammatory responses and apoptosis in HIRI, thereby improving the therapeutic effect. We demonstrated that C-dots with anti-oxidative stress and anti-inflammatory properties improved the survival of THLE-2 cells under H2O2 and LPS-treated conditions. In the animal model, our results showed that the impregnation of C-dots could effectively scavenge ROS and reduce the expression of inflammatory cytokines, such as IL-1β, IL-6, IL-12, and TNF-α, resulting in a profound therapeutic effect in the HIRI. To reveal the potential therapeutic mechanism, transcriptome sequencing was performed and the relevant genes were validated, showing that the C-dots exert hepatoprotective effects by modulating the hepatic inflammatory network and inhibiting apoptosis. CONCLUSIONS: With negligible systemic toxicity, our findings substantiate the potential of C-dots as a therapeutic approach for HIRI, thereby offering a promising intervention strategy for clinical implementation.