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 , and 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.

中文翻译：

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与脂肪干细胞和 L6 共再细胞化的可灌注脂肪脱细胞细胞外基质生物支架促进体积肌损失后功能性骨骼肌再生

肌肉组织工程是一种很有前途的治疗体积肌肉损失（VML）的策略。其中，脱细胞细胞外基质（dECM）生物支架在恢复肌肉功能方面表现出一定的效果。然而，对于dECM生物支架能否有效再生肌纤维、恢复肌肉功能，研究人员的结果不一致甚至相互矛盾。这表明基于 dECM 生物支架的治疗策略需要进一步优化和开发。在这项研究中，我们采用了再细胞化方法，通过血管蒂将脂肪源干细胞（ASC）和L6灌注到脂肪dECM（adECM）中。一方面，该策略确保支架内种子细胞的数量充足且分布均匀。另一方面，辅助L6细胞解决了ASC成肌分化效率低的问题。随后，治疗VML动物实验表明，联合再细胞化策略比单一ASCs再细胞化策略能够改善肌肉再生和血管生成，且前者的TA具有更大的肌肉收缩强度。进一步的单核RNA测序（snRNA-seq）分析发现，L6细胞诱导ASC转化为高表达、和基因的新细胞亚群，具有更强的定向生肌分化能力。本研究表明，通过血管蒂共接种ASCs和L6细胞是一种有前途的adECM生物支架再细胞化策略，基于此构建的工程化肌肉组织对VML具有显着的治疗效果。总的来说，这项研究为优化和开发基于 dECM 的治疗策略提供了一个新的范例。