Tendon injuries are prevalent in physical activities and sports. Tendon heals slowly after injuries. The results of conservative treatments and surgery are not satisfactory with high re-injury rate and scar tissue formation. The application of mesenchymal stem cells (MSCs) to the injured tendons was reported to promote tendon repair. Recent studies have suggested that MSCs supported tendon repair via the secretion of paracrine factors. Extracellular vesicles (EVs) are a heterogeneous group of cell-derived membranous structures that are produced and secreted by most eukaryotic cells. They carry a plethora of proteins, lipids, microRNA and mRNA which reprogram the recipient cells and are involved in multiple physiological and pathological processes. EVs were shown to promote tissue repair and mediate the healing effects of MSCs. In this review, I aim to review the recent literature on the promotion of tendon repair using EVs-derived from MSCs (MSC-EVs). The mechanisms underlying these actions are also reviewed and future research directions are discussed. Better understanding of the roles of MSC-EVs in tendon repair would offer a new treatment strategy to circumvent this devastating soft tissue disorder.

Graphical Abstract

肌腱损伤在体育活动和运动中很普遍。肌腱受伤后愈合缓慢。保守治疗和手术治疗效果不理想，再损伤率高，瘢痕组织形成。据报道，将间充质干细胞 (MSCs) 应用于受伤的肌腱可促进肌腱修复。最近的研究表明，间充质干细胞通过分泌旁分泌因子支持肌腱修复。细胞外囊泡 (EV) 是由大多数真核细胞产生和分泌的一组异质的细胞衍生膜结构。它们携带大量的蛋白质、脂质、microRNA 和 mRNA，这些蛋白质、脂质、microRNA 和 mRNA 可以重新编程受体细胞并参与多种生理和病理过程。EVs 被证明可以促进组织修复并介导 MSCs 的愈合作用。在本次审查中，我的目的是回顾最近关于使用源自 MSCs 的 EVs (MSC-EVs) 促进肌腱修复的文献。还回顾了这些行动背后的机制，并讨论了未来的研究方向。更好地了解 MSC-EV 在肌腱修复中的作用将为规避这种破坏性的软组织疾病提供一种新的治疗策略。

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