Tendon is a highly hierarchical and oriented tissue that provides high mechanical strength. Tendon injuries lead to loss of function, disability, and a decrease in quality of life. The limited healing capacity of tendon tissue leads to scar tissue formation, which can affect mechanical strength and cause a re-tear. Tissue engineering can be the solution to achieving complete and proper healing of tendon. The developed constructs should be mechanically strong while maintaining a suitable environment for cell proliferation. In this study, a dual-phase fibrous scaffold was produced by combining fibrous mats produced by rotary jet spinning (RJS) and wet electrospinning (WES), with the intent of improving the healing capacity of the construct. Dual-phase scaffolds were formed from aligned poly(ϵ-caprolactone) (PCL) fibers (Shell) produced by RJS and randomly oriented PCL or PCL/gelatin fibers (Core) produced by WES systems. The scaffolds mimicked i) the repair phase of tendon healing, in which randomly-oriented collagen type III is deposited by randomly-oriented WES fibers and ii) the remodeling stage, in which aligned collagen type I fibers are deposited by aligned RJS fibers. In vitro studies showed that the presence of randomly-oriented core fibers inside the aligned PCL fiber shell of the dual-phase scaffold increased the initial attachment and viability of cells. Scanning electron microscopy and confocal microscopy analysis showed that the presence of aligned RJS fibers supported the elongation of cells through aligned fibers which improves tendon tissue healing by guiding oriented cell proliferation and extracellular matrix deposition. Tenogenic differentiation of human adipose-derived mesenchymal stem cells on scaffolds was studied when supplemented with growth differentiation factor 5 (GDF-5). GDF-5 treatment improved the viability, collagen type III deposition and scaffold penetration of human adipose derived stem cells. The developed FSPCL/ESPCL-Gel 3:1 scaffold (FS = centrifugal force spinning/RJS, ES = wet electrospinning, Gel = gelatin) sustained high mechanical strength, and improved cell viability and orientation while supporting tenogenic differentiation.

肌腱是一种高度分层和定向的组织，具有高机械强度。肌腱损伤会导致功能丧失、残疾和生活质量下降。肌腱组织的有限愈合能力会导致疤痕组织形成，从而影响机械强度并导致再次撕裂。组织工程可以成为实现肌腱完全、正确愈合的解决方案。开发的结构应该具有机械强度，同时保持适合细胞增殖的环境。在这项研究中，通过结合旋转喷射纺丝（RJS）和湿式静电纺丝（WES）生产的纤维垫来生产双相纤维支架，旨在提高结构的愈合能力。双相支架由 RJS 生产的对齐聚（ε-己内酯）（PCL）纤维（壳）和 WES 系统生产的随机取向的 PCL 或 PCL/明胶纤维（芯）形成。该支架模仿了 i) 肌腱愈合的修复阶段，其中随机取向的 III 型胶原蛋白由随机取向的 WES 纤维沉积，以及 ii) 重塑阶段，其中对齐的 I 型胶原纤维由对齐的 RJS 纤维沉积。体外研究表明，双相支架的对齐 PCL 纤维壳内存在随机取向的芯纤维，增加了细胞的初始附着和活力。扫描电子显微镜和共聚焦显微镜分析表明，对齐的 RJS 纤维的存在通过对齐的纤维支持细胞的伸长，从而通过引导定向细胞增殖和细胞外基质沉积来改善肌腱组织愈合。当补充生长分化因子 5 (GDF-5) 时，研究了支架上人脂肪来源的间充质干细胞的肌腱分化。GDF-5 治疗改善了人类脂肪干细胞的活力、III 型胶原沉积和支架渗透。开发的 FSPCL/ESPCL-Gel 3:1 支架（FS = 离心力旋转/RJS，ES = 湿式静电纺丝，Gel = 明胶）保持高机械强度，并改善细胞活力和方向，同时支持肌腱分化。