Decellularized Matrices for the Treatment of Tissue Defects: from Matrix Origin to Immunological Mechanisms.

Decellularized matrix transplantation has emerged as a promising therapeutic approach for repairing tissue defects, with numerous studies assessing its safety and efficacy in both animal models and clinical settings. The host immune response elicited by decellularized matrix grafts of natural biological origin plays a crucial role in determining the success of tissue repair, influenced by matrix heterogeneity and the inflammatory microenvironment of the wound. However, the specific immunologic mechanisms underlying the interaction between decellularized matrix grafts and the host immune system remain elusive. This article reviews the sources of decellularized matrices, available decellularization techniques, and residual immunogenic components. It focuses on the host immune response following decellularized matrix transplantation, with emphasis on the key mechanisms of Toll-like receptor, T-cell receptor, and TGF-β/SMAD signaling in the stages of post-transplantation immunorecognition, immunomodulation, and tissue repair, respectively. Furthermore, it highlights the innovative roles of TLR10 and miR-29a-3p in improving transplantation outcomes. An in-depth understanding of the molecular mechanisms underlying the host immune response after decellularized matrix transplantation provides new directions for the repair of tissue defects.