Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Tissue Engineering, 639 Zhi Zao Ju Road, Shanghai 200011, PR China.
Biomaterials. 2009 Dec;30(35):6724-30. doi: 10.1016/j.biomaterials.2009.08.054. Epub 2009 Sep 25.
Proper cell source is one of the key issues for tendon engineering. Our previous study showed that dermal fibroblasts could be used to successfully engineer tendon in vivo and tenocytes could engineer neo-tendon in vitro with static strain. This study further investigated the possibility of engineering human neo-tendon tissue in vitro using dermal fibroblasts. Human dermal fibroblasts were seeded on polyglycolic acid (PGA) fibers pre-fixed on a U-shape as a mechanical loading group, or simply cultured in a dish as a tension-free group. In addition, human tenocytes were also seeded on PGA fibers with tension as a comparison to human dermal fibroblasts. The results showed that human neo-tendon tissue could be generated using dermal fibroblasts during in vitro culture under static strain and the tissue structure became more mature with the increase of culture time. Longitudinally aligned collagen fibers and spindle shape cells were observed histologically and collagen fibril diameter and tensile strength increased with time and reached a peak at 14 weeks. In contrast, the dermal fibroblast-PGA constructs failed to form neo-tendon, but formed disorganized fibrous tissue in tension-free condition with significantly weaker strength and poor collagen fiber formation. Interestingly, neo-tendon tissues generated with human dermal fibroblasts were indistinguishable from the counterpart engineered with human tenocytes, which supports the viewpoint that human dermal fibroblasts is likely to replace tenocytes for future tendon graft development in vitro with dynamic mechanical loading in a bioreactor system.
细胞来源恰当是肌腱工程的关键问题之一。我们之前的研究表明，真皮成纤维细胞可成功用于体内肌腱工程，静态应变下腱细胞可用于体外构建新的肌腱。本研究进一步探讨了使用真皮成纤维细胞在体外构建人新肌腱组织的可能性。将人真皮成纤维细胞种植在预先固定在 U 形上的聚乙醇酸（PGA）纤维上作为力学加载组，或简单地在培养皿中培养作为无张力组。此外，还将人腱细胞种植在具有张力的 PGA 纤维上，与真皮成纤维细胞进行比较。结果表明，在体外静态应变培养下，真皮成纤维细胞可产生人新肌腱组织，且组织结构随培养时间的延长而变得更加成熟。组织学观察到纵向排列的胶原纤维和梭形细胞，胶原纤维直径和拉伸强度随时间增加而增加，在 14 周时达到峰值。相比之下，在无张力条件下，真皮成纤维细胞-PGA 构建物未能形成新的肌腱，而是形成了无组织的纤维组织，强度显著较弱，胶原纤维形成较差。有趣的是，用人真皮成纤维细胞生成的新肌腱组织与用人腱细胞构建的新肌腱组织无法区分，这支持了真皮成纤维细胞可能取代腱细胞，用于未来在生物反应器系统中进行动态力学加载的体外肌腱移植物开发的观点。
