Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, UK.
Med Eng Phys. 2013 Feb;35(2):205-10. doi: 10.1016/j.medengphy.2012.08.015. Epub 2012 Sep 11.
Tendons are known to adapt to their mechanical environment, however high frequency low magnitude (HFLM) loading regimes (10-50Hz), which are effective in promoting bone anabolic effects, have not been investigated in controlled conditions in tendon. In vitro loading systems (IVLS) enable precise characterisation of the link between their controlled mechanical environment and cultured tissue biological response. We report a novel IVLS design using an applied magnetic field to produce time varying loading in cultured rat tail tendon fascicles (RTTF). The design was validated through magnetic flux, load cell and viability measurements, and we report the results of preliminary experiments testing the hypothesis that an HFLM loading regime will maintain the biochemical and mechanical properties of fresh RTTF in culture over 7 days. Tissue viability was maintained for 7 days under all loading conditions, and the average peak load applied to RTTFs using the IVLS at 20Hz was 0.125N. RTTFs cultured for 7 days with HFLM loading showed a trend for a higher tangent modulus than fresh tissue, and significantly higher modulus than unloaded RTTFs. GAG content of HFLM cultured RTTFs was not significantly changed from that of fresh RTTFs. This novel, validated IVLS will provide new knowledge of tendon mechanobiology and has already shown the potential of clinically relevant HFLM loading for influencing tendon biology.
肌腱已知会适应其机械环境，但高频低幅度（HFLM）加载模式（10-50Hz）在促进骨合成代谢作用方面非常有效，尚未在受控条件下在肌腱中进行研究。体外加载系统（IVLS）能够精确描述其受控机械环境与培养组织生物反应之间的联系。我们报告了一种使用外加磁场在培养的大鼠尾腱束（RTTF）中产生时变加载的新型 IVLS 设计。该设计通过磁通量、称重传感器和活力测量进行了验证，我们报告了初步实验的结果，这些实验检验了以下假设：HFLM 加载模式将在培养物中维持新鲜 RTTF 的生化和机械特性超过 7 天。在所有加载条件下，组织活力都能维持 7 天，在 20Hz 下使用 IVLS 施加到 RTTFs 的平均峰值负载为 0.125N。经过 HFLM 加载培养 7 天的 RTTF 的切线模量比新鲜组织高，比未加载的 RTTF 高得多。HFLM 培养的 RTTF 的 GAG 含量与新鲜 RTTF 相比没有明显变化。这种新型经过验证的 IVLS 将为肌腱力学生物学提供新知识，并且已经显示出具有临床相关性的 HFLM 加载对影响肌腱生物学的潜力。
