Department of Orthopedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan.
Department of Orthopedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
Int J Mol Sci. 2020 May 2;21(9):3221. doi: 10.3390/ijms21093221.
Tendons are hypocellular and hypovascular tissues, and thus, their natural healing capacity is low. In this study, we sought to evaluate the efficacy of platelet-rich fibrin (PRF) to serve as a bioactive scaffold in promoting the healing of rabbit Achilles tendon injury. For in vitro study, the essence portion of PRF was determined through bioluminescent assay. Furthermore, we analyzed the time-sequential cytokines-release kinetics of PRF and evaluated their effects on tenocytes proliferation and tenogenic gene expressions. In animal study, the rabbit Achilles tendon defect was left untreated or implanted with normal/heat-denatured PRF scaffolds. Six weeks postoperatively, the specimens were evaluated through sonographic imaging and histological analysis. The results revealed significantly more activated platelets on bottom half of the PRF scaffold. Cytokine concentrations released from PRF could be detected from the first hour to six days. For the in vitro study, PRF enhanced cell viability and collagen I, collagen III, tenomodulin, and tenascin gene expression compared to the standard culture medium. For in vivo study, sonographic images revealed significantly better tendon healing in the PRF group in terms of tissue echogenicity and homogeneity. The histological analysis showed that the healing tissues in the PRF group had more organized collagen fiber, less vascularity, and minimal cartilage formation. In conclusion, bioactive PRF promotes in vitro tenocytes viability and tenogenic phenotypic differentiation. Administration of a PRF scaffold at the tendon defect promotes tissue healing as evidenced by imaging and histological outcomes.
肌腱是细胞稀少和血管稀少的组织，因此，其自然愈合能力较低。在这项研究中，我们试图评估富血小板纤维蛋白（PRF）作为生物活性支架促进兔跟腱损伤愈合的效果。为了进行体外研究，我们通过生物发光测定法确定了 PRF 的本质部分。此外，我们分析了 PRF 的时相细胞因子释放动力学，并评估了它们对肌腱细胞增殖和肌腱形成基因表达的影响。在动物研究中，兔跟腱缺损未治疗或植入正常/热变性的 PRF 支架。术后 6 周，通过超声成像和组织学分析评估标本。结果显示 PRF 支架的下半部分有更多的活化血小板。从第 1 小时到第 6 天，可以检测到 PRF 释放的细胞因子浓度。对于体外研究，与标准培养基相比，PRF 增强了细胞活力和胶原 I、胶原 III、腱调蛋白和腱蛋白聚糖基因的表达。对于体内研究，超声图像显示，在组织回声和均匀性方面，PRF 组的跟腱愈合明显更好。组织学分析显示，PRF 组的愈合组织具有更有组织的胶原纤维、较少的血管形成和最小的软骨形成。总之，生物活性 PRF 促进体外肌腱细胞的活力和肌腱形成表型分化。PRF 支架在肌腱缺损处的给药通过影像学和组织学结果证实了组织愈合。
