SVF Cell Sheets as 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 adsorption rate and challenges in establishing timely and effective neovascularization postsurgery. In this study, the authors produced SVF cell sheets from adipose-derived stromal vascular fraction (SVF) through 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 adsorption 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 can replace perichondrium and promote the expression of proangiogenic growth factors Ang-1 and VEGF, thereby promoting local microvascular regeneration, reducing chondrocyte pyroptosis, and promoting the formation of cartilage blocks. This strategy provides a potential new method for autologous cartilage grafting, which will help solve the dilemma of limited sources of cartilage tissue in clinical practice and provide natural autologous cartilage filling materials for the treatment of craniofacial defects.