Tissue engineering, especially cell sheets-based engineering, offers a promising approach to tendon regeneration; however, obtaining a sufficient source of cells for tissue engineering applications is challenging. Adipose-derived stem cells (ASCs) are essential sources for tissue regeneration and have been shown to have the potential for tenogenic differentiation in vitro via induction by growth differentiation factor 5 (GDF-5). In this study, we explored the feasibility of ASCs cell sheets stimulated by GDF-5 for engineered tendon repair. As shown by quantitative polymerase chain reaction and western blotting, tenogenesis-related markers (Col I&III, TNMD, biglycan, and tenascin C) were significantly increased in GDF-5-induced ASCs cell sheets compared with the uninduced. Moreover, the levels of SMAD2/3 proteins and phospho-SMAD1/5/9 were significantly enhanced, demonstrating that GDF-5 may exert its functions through phosphorylation of SMAD1/5/9. Furthermore, the cell sheets were combined with P(LLA-CL)/Silk fibroin nanoyarn scaffolds to form constructs for tendon tissue engineering. Terminal deoxynucleotidyl transferase dUTP nick end labeling and immunofluorescence assays demonstrated favorable cell viability and tenogenesis-related marker expression in GDF-5-induced constructs. In addition, the constructs showed the potential for tendon repair in rabbit models, as demonstrated by histological, immunohistochemical, and biomechanical analyses. In our study, we successfully produced a new tissue-engineered tendon by the combination of GDF-5-induced ASCs cell sheets and nanoyarn scaffold which is valuable for tendon regeneration.

组织工程，尤其是基于细胞片的工程，为肌腱再生提供了一种有希望的方法。然而，获得足够的细胞来源用于组织工程应用是具有挑战性的。脂肪干细胞（ASC）是组织再生的重要来源，并已显示具有通过生长分化因子5（GDF-5）诱导在体外进行肌腱分化的潜力。在这项研究中，我们探索了由GDF-5刺激的ASCs细胞片用于工程化肌腱修复的可行性。如定量聚合酶链反应和蛋白质印迹所显示的，与未诱导的相比，GDF-5诱导的ASCs细胞片中与腱发生相关的标记（Col I＆III，TNMD，双糖链蛋白和腱生蛋白C）显着增加。此外，SMAD2 / 3蛋白和磷酸-SMAD1 / 5/9的水平显着提高，表明GDF-5可能通过SMAD1 / 5/9的磷酸化发挥其功能。此外，将细胞片与P（LLA-CL）/丝素蛋白纳米纱支架组合以形成用于肌腱组织工程的构建体。末端脱氧核苷酸转移酶dUTP缺口末端标记和免疫荧光分析表明在GDF-5诱导的构建体中具有良好的细胞活力和与腱鞘生成相关的标志物表达。另外，如组织学，免疫组织化学和生物力学分析所证实的，该构建体在兔模型中显示出腱修复的潜力。在我们的研究中