Cai Jiangyu, Xie Xianrui, Li Dandan, Wang Liren, Jiang Jia, Mo Xiumei, Zhao Jinzhong
Department of Sports Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China.
Biomater Sci. 2020 Aug 11;8(16):4413-4425. doi: 10.1039/d0bm00816h.
Tendon injury is common in sports and other rigorous activities, which may result in dysfunction and disability. Recently, scaffolds with a knitted structure have been widely applied for tendon tissue engineering. The purpose of this study was to fabricate a novel knitted tendon scaffold made of microfiber/nanofiber core-sheath yarns and evaluate the biocompatibility and the effect of tenogenic differentiation and tendon tissue regeneration in vitro and in vivo. Poly(ε-caprolactone) (PCL) microfibers, PCL microfibers-PCL nanofibers (PCL-PCL) and PCL microfiber-silk fibroin/poly(l-lactic acid-co-ε-caprolactone) nanofiber (SF/PLCL) core-sheath yarns were fabricated and then knitted with an automatic knitting machine to produce PCL, PCL-PCL and PCL-SF/PLCL fabric scaffolds. The characterization of the scaffolds was performed by using scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy and an universal mechanical instrument. The in vitro experiment showed that rabbit bone marrow stem cells seeded on the scaffolds exhibited an elongated morphology and proliferated better in the PCL-SF/PLCL group, as compared to the PCL and PCL-PCL groups. Moreover, the PCL-SF/PLCL scaffold promoted the tenogenic differentiation of the cells for the highest expression levels of the tendon-related genes through down-regulating p-ERK1/2 expression among the three groups. Furthermore, the in vivo study in a rabbit patellar defect model demonstrated that the PCL-SF/PLCL scaffold could enhance the tissue regeneration and remodeling process as indicated by the better structural and biomechanical properties according to the results of histology, immunohistochemistry, transmission electron microscope examination and biomechanical tests. Therefore, the PCL-SF/PLCL scaffold is proved to be a promising biomaterial for tendon tissue engineering and a potential candidate for clinical treatment of tendon injury in the future.
肌腱损伤在体育活动和其他高强度活动中很常见，可能导致功能障碍和残疾。近年来，具有针织结构的支架已广泛应用于肌腱组织工程。本研究的目的是制备一种由微纤维/纳米纤维芯鞘纱线制成的新型针织肌腱支架，并评估其生物相容性以及在体外和体内的成腱分化作用和肌腱组织再生效果。制备了聚（ε-己内酯）（PCL）微纤维、PCL微纤维-PCL纳米纤维（PCL-PCL）和PCL微纤维-丝素蛋白/聚（L-乳酸-co-ε-己内酯）纳米纤维（SF/PLCL）芯鞘纱线，然后用自动针织机编织成PCL、PCL-PCL和PCL-SF/PLCL织物支架。通过扫描电子显微镜、衰减全反射傅里叶变换红外光谱和万能力学仪器对支架进行表征。体外实验表明，与PCL和PCL-PCL组相比，接种在支架上的兔骨髓干细胞在PCL-SF/PLCL组中呈现出伸长的形态且增殖更好。此外，PCL-SF/PLCL支架通过下调三组中p-ERK1/2的表达，促进了细胞的成腱分化，使肌腱相关基因的表达水平达到最高。此外，在兔髌腱缺损模型中的体内研究表明，根据组织学、免疫组织化学、透射电子显微镜检查和生物力学测试的结果，PCL-SF/PLCL支架具有更好的结构和生物力学性能，能够促进组织再生和重塑过程。因此，PCL-SF/PLCL支架被证明是一种有前途的用于肌腱组织工程的生物材料，也是未来肌腱损伤临床治疗的潜在候选材料。
