Resveratrol-loaded chitosan nanoparticles and adipose-derived stem cell–conditioned medium for liver protection against ischemia–reperfusion injury

Ischemia-reperfusion injury (IRI) continues to be a significant obstacle in liver transplantation and often results in graft dysfunction and suboptimal outcomes after transplantation. The current preservation solutions, such as the University of Wisconsin (UW) solution, provide limited protection against oxidative stress, inflammation, and apoptosis. The present study was undertaken to design and test a bioactive preservation solution supplemented with resveratrol-loaded chitosan nanoparticles (Resv-CNPs) and adipose-derived stem cell conditioned medium (ASC-CM) to achieve hepatoprotection during IRI. Resv-CNPs were synthesized using the ionic gelation method and characterized for encapsulation efficiency, release profile, and antioxidant activity. HepG2 cells were exposed to an in vitro IRI model, which involved 24h cold ischemia in UWCM solution followed by 48h reperfusion. Cell viability was evaluated by MTT assay, and ALT, AST, LDH, HMGB1, IL-1β, and IL-6 were measured by ELISA. An in vivo rat model was used to validate the hepatic preservation effect after 24h of cold storage in different solutions. Histopathological changes were assessed by H&E staining and Suzuki scoring. Resv-CNPs had an encapsulation efficiency of 46.21±7.12%, and it showed a biphasic release pattern. The drug release from nanoparticles could provide sustained release of resveratrol for up to 72h. Free resveratrol and Resv-CNPs showed excellent DPPH radical scavenging activity. UWCM supplemented with Resv-CNPs dose-dependently increased hepatocyte viability and significantly decreased injury and inflammatory markers compared to free resveratrol and blank nanoparticles in vitro. In vivo, livers preserved with UWCM + Resv-CNPs showed decreased necrosis, reduced liver injury markers, better architecture, and lower Suzuki scores. The incorporation of Resv-CNPs and ASC-CM into the UW solution provided strong antioxidant, anti-inflammatory, and anti-apoptotic protection against hepatic IRI. This next-generation preservation formulation may improve graft quality, extend storage time, and have the potential to enhance transplantation outcomes.