Perfusable adipose decellularized extracellular matrix biological scaffold co-recellularized with adipose-derived stem cells and L6 promotes functional skeletal muscle regeneration following volumetric muscle loss.

Muscle tissue engineering is a promising therapeutic strategy for volumetric muscle loss (VML). Among them, decellularized extracellular matrix (dECM) biological scaffolds have shown certain effects in restoring muscle function. However, researchers have inconsistent or even contradictory results on whether dECM biological scaffolds can efficiently regenerate muscle fibers and restore muscle function. This suggests that therapeutic strategies based on dECM biological scaffolds need to be further optimized and developed. In this study, we used a recellularization method of perfusing adipose-derived stem cells (ASCs) and L6 into adipose dECM (adECM) through vascular pedicles. On one hand, this strategy ensures sufficient quantity and uniform distribution of seeded cells inside scaffold. On the other hand, auxiliary L6 cells addresses the issue of low myogenic differentiation efficiency of ASCs. Subsequently, the treatment of VML animal experiments showed that the combined recellularization strategy can improve muscle regeneration and angiogenesis than the single ASCs recellularization strategy, and the TA of former had greater muscle contraction strength. Further single-nucleus RNA sequencing (snRNA-seq) analysis found that L6 cells induced ASCs transform into a new subpopulation of cells highly expressing Mki67 , CD34 and CDK1 genes, which had stronger ability of oriented myogenic differentiation. This study demonstrates that co-seeding ASCs and L6 cells through vascular pedicles is a promising recellularization strategy for adECM biological scaffolds, and the engineered muscle tissue constructed based on this has significant therapeutic effects on VML. Overall, this study provides a new paradigm for optimizing and developing dECM-based therapeutic strategies. Study on the therapeutic effect and mechanism of vascularized adECM biological scaffolds co-recellularized by ASCs and L6 cells (myoblasts) for VML treatment. Seeding ASCs and L6 cells into biological scaffolds via vascular pedicles ensures uniform cellular distribution within the scaffold and promotes functional muscle fibers regeneration. Meanwhile, under the assistance of L6 cells, ASCs in adECM biological scaffolds transform into a new subpopulation with high expression of Mki67 , CD34 and CDK1 genes. This subpopulation has greater oriented myogenic differentiation potential, forms more mature muscle fibers, and significantly enhances muscle regeneration for VML. [Display omitted] [ABSTRACT FROM AUTHOR]