Abstract
<title>Abstract</title> <p> <bold>Background</bold> Autologous diced costal cartilage is widely used in rhinoplasty and auricular reconstruction; however, long-term graft survival is often compromised by oxidative stress, inflammation, and insufficient vascularization after transplantation. Emerging evidence suggests that NLRP3/Caspase-1/GSDMD-mediated pyroptosis and impaired autophagy contribute to chondrocyte injury and cartilage degeneration. This study investigated whether adipose-derived stem cell (ADSC) sheets could improve diced cartilage graft survival by regulating the autophagy–pyroptosis axis. <bold>Methods</bold> A rabbit ectopic transplantation model was established to evaluate the effects of ADSC sheet wrapping on diced cartilage grafts in vivo. Histological staining, TUNEL assay, immunohistochemistry, and immunofluorescence were performed to assess graft morphology, apoptosis, oxidative stress, pyroptosis, and autophagy. In vitro, human chondrocytes were exposed to H₂O₂-induced oxidative stress and co-cultured with ADSCs. Cell viability, reactive oxygen species (ROS), migration, inflammatory cytokines, and related molecular markers were analyzed by CCK-8, flow cytometry, RT-qPCR, western blotting, ELISA, and transmission electron microscopy. Autophagy was modulated using rapamycin and bafilomycin A1. Statistical analyses were performed using Student’s t-test or one-way ANOVA. <bold>Results</bold> ADSC sheet-wrapped grafts showed improved cartilage architecture, increased retention of chondrocyte lacunae, reduced apoptosis and nuclear loss, and enhanced type II collagen deposition compared with control and autologous perichondrium groups. ADSC sheets significantly suppressed NLRP3, Caspase-1, GSDMD, and NOX4 expression, while increasing SOD1, LC3, and Beclin-1 and decreasing P62, indicating reduced oxidative stress, inhibited pyroptosis, and enhanced autophagy. In vitro, ADSCs attenuated H₂O₂-induced oxidative stress, reduced ROS accumulation and inflammatory cytokine secretion, restored autophagic flux, and suppressed pyroptosis in chondrocytes. Rapamycin further enhanced these protective effects, whereas bafilomycin A1 partially reversed them. Transcriptomic analysis further confirmed coordinated regulation of autophagy-, inflammation-, and metabolism-related pathways. <bold>Conclusions</bold> ADSC sheets function as a biomimetic regenerative niche that improves the transplantation microenvironment and enhances diced cartilage graft survival by promoting autophagy and suppressing NLRP3/Caspase-1/GSDMD-mediated pyroptosis. This strategy provides a promising stem cell-based approach for improving long-term cartilage graft stability in reconstructive surgery. </p>