There is increasing interest in understanding how mechanical cues (e.g., physical forces due to kicking and other movements) influence the embryological development of tissues and organs. For example, recent studies from our laboratory and others have used the chick embryo model to demonstrate that the compositional and mechanical properties of developing tendons are strongly regulated by embryo movement frequency. However, current research tools for manipulating embryological movements and in ovo (or in utero) mechanical forces are generally limited to chemical treatments that either paralyze or overstimulate muscles without allowing for precise control of physical cues. Thus, in this study, we introduce an instrument that enables application of passive, dynamic ankle flexion at prescribed amplitudes and frequencies in live, developing chick embryos. This device meets the design goals of allowing for precise (<1.5°) control of different waveforms of ankle motion at a physiologically relevant frequency (0.17 Hz) across a range of ankle angles (0-90° plantarflexion) with maintenance of embryo viability comparable to other methods. Impact Statement We describe the design and implementation of a novel bioreactor to precisely control ankle motion in a chick embryo within its physiological environment. The chick embryo has been used for decades to study mechanobiology of musculoskeletal tissue development and regeneration, but approaches have been limited to chemical treatments that either paralyze or overstimulate muscles without allowing for precise control of physical cues. Thus, this novel instrument is a major advancement over current research tools for manipulating chick embryological movements in ovo (or in utero).

中文翻译：

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评估卵活母鸡胚胎中被动关节负荷影响的生物反应器的设计。

人们越来越了解机械提示（例如，由于踢和其他运动引起的物理力）如何影响组织和器官的胚胎发育。例如，我们实验室和其他实验室的最新研究已使用雏鸡胚胎模型来证明发育中的肌腱的组成和力学性能受胚胎运动频率的强烈调节。但是，当前用于操纵胚胎运动和卵（或子宫内）机械力的研究工具通常仅限于使肌肉麻痹或过度刺激而无法精确控制物理线索的化学治疗。因此，在这项研究中，我们介绍了一种仪器，该仪器可在生活中以规定的幅度和频率应用被动的动态踝关节屈曲，发育的雏鸡胚胎。该设备符合以下设计目标：允许在生理相关频率（0.17 Hz）范围内的整个踝角范围（0-90°足屈）精确控制（<1.5°）踝运动的不同波形，同时保持胚胎的生存能力其他方法。影响陈述我们描述了一种新型生物反应器的设计和实现，该反应器可在其生理环境内精确控制雏鸡胚胎的脚踝运动。鸡胚已被用于研究肌肉骨骼组织发育和再生的力学生物学数十年，但方法仅限于使肌肉麻痹或过度刺激而无法精确控制物理线索的化学治疗。从而，