School of Life Sciences, Nantong University, Nantong, Jiangsu 226019, China; College of Chemistry, Chemical Engineering & Biotechnology, Donghua University, Shanghai 201620, China; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI, USA.
Department of Orthopedics and Orthopedic Institute, Clinical Medical College of Yangzhou University, Subei People's Hospital of Jiangsu Province, Yangzhou, Jiangsu 225001, China.
Int J Biol Macromol. 2021 Feb 15;170:248-260. doi: 10.1016/j.ijbiomac.2020.12.152. Epub 2020 Dec 29.
Functional tendon tissue engineering depends on harnessing the biochemical and biophysical cues of the native tendon extracellular matrix. In this study, we fabricated highly-aligned poly(L-lactic acid) (PLLA) fibers with surfaces decorated by two of the crucial tendon ECM components, type 1 collagen (COL1) and chondroitin sulfate (CS), through a coaxial stable jet electrospinning approach. Effects of the biomimetic COL1-CS (shell)/PLLA (core) fibers on the tenogenic differentiation of human mesenchymal stem cells (hMSCs) in vitro were investigated. Higher rates of cell spreading and proliferation are observed on the aligned COL1-CS/PLLA fibers compared to that on the plain PLLA fibers. Expression of the tendon-associated genes scleraxis (SCX) and COL1 as well as protein tenomodulin (TNMD) are significantly increased. Introduction of mechanical stimulation gives rise to synergistic effect on tenogenic differentiation of hMSCs. Higher expression of TGF-β2, TGFβR-II, and Smad3 by the cells on the COL1-CS/PLLA fiber substrates are observed, which indicates that COL1-CS/PLLA ultrafine fibers dictate the hMSC tenogenic differentiation through activating the TGF-β signaling pathway. Animal study in rat Achilles tendon repair model corroborated the promoting role of COL1-CS/PLLA in regenerating a tendon-like tissue. Thus, our highly aligned biomimicking fibers may serve as an efficient scaffolding system for functional tendon regeneration.
功能性肌腱组织工程依赖于利用天然肌腱细胞外基质的生化和生物物理线索。在这项研究中，我们通过同轴稳定射流纺丝方法制造了高度排列的聚（L-乳酸）（PLLA）纤维，其表面装饰有两种关键的肌腱 ECM 成分，即 I 型胶原蛋白（COL1）和硫酸软骨素（CS）。研究了仿生 COL1-CS（壳）/PLLA（核）纤维对人骨髓间充质干细胞（hMSCs）体外肌腱分化的影响。与 PLA 纤维相比，在 COL1-CS/PLLA 纤维上观察到细胞铺展和增殖的速度更快。与 COL1-CS 相比，COL1-CS/PLLA 纤维上的肌腱相关基因 scleraxis (SCX) 和 COL1 以及蛋白 tenomodulin (TNMD) 的表达显著增加。引入机械刺激对 hMSCs 的肌腱分化产生协同作用。COL1-CS/PLLA 纤维基上的细胞 TGF-β2、TGFβR-II 和 Smad3 的表达更高，这表明 COL1-CS/PLLA 超细微纤维通过激活 TGF-β 信号通路来控制 hMSC 的肌腱分化。在大鼠跟腱修复模型中的动物研究证实了 COL1-CS/PLLA 在再生类似肌腱组织中的促进作用。因此，我们高度排列的仿生纤维可以作为功能性肌腱再生的有效支架系统。
