SVF cell sheets: A new multicellular material-based strategy for promoting angiogenesis and regeneration in diced cartilage grafts

Autologous diced cartilage, while biocompatible and easy to shape, is limited in clinical application due to its high resorption rate and challenges in establishing timely and effective neovascularization post-surgery. In this study, we produced SVF cell sheets from adipose-derived stromal vascular fraction (SVF) via enzymatic digestion, employing a temperature-sensitive culture system. Our in vivo and in vitro experiments validated that SVF cell sheets, when wrapped around granular cartilage, exhibited a notable promotion of cartilage regeneration and mitigated granular cartilage resorption in a rabbit diced cartilage graft model. Our findings demonstrate that SVF cell sheets facilitated effective neovascularization and timely cartilage block formation by secreting VEGF and Ang-1 while also suppressing the expression of pyroptotic proteins like NLRP3, Caspase1, and GSDMD. As a biofilm, derived from a multicellular source, SVF cell sheets hold promise in promoting neovascularization and cartilage regeneration in diced cartilage grafts while also preventing chondrocyte pyroptosis, presenting a potential novel approach for autologous diced cartilage transplantation.