Department of Bioengineering, University of California-San Diego, La Jolla, CA, USA.
Lab Chip. 2017 Oct 11;17(20):3447-3461. doi: 10.1039/c7lc00512a.
Engineered skeletal muscle tissues can be used for in vitro studies that require physiologically relevant models of native tissues. Herein, we describe the development of a three-dimensional (3D) skeletal muscle tissue that recapitulates the architectural and structural complexities of muscle within a microfluidic device. Using a 3D photo-patterning approach, we spatially confined a cell-laden gelatin network around two bio-inert hydrogel pillars, which induce uniaxial alignment of the cells and serve as anchoring sites for the encapsulated cells and muscle tissues as they form and mature. We have characterized the tissue morphology and strain profile during differentiation of the cells and skeletal muscle tissue formation by using a combination of fluorescence microscopy and computational tools. The time-dependent strain profile suggests the existence of individual cells within the gelatin matrix, which differentiated to form a multinucleated skeletal muscle tissue bundle as a function of culture time. We have also developed a method to calculate the passive tension generated by the engineered muscle tissue bundles suspended between two pillars. Finally, as a proof-of-concept we have examined the applicability of the skeletal muscle-on-chip system as a screening platform and in vitro muscle injury model. We studied the dose-dependent effect of cardiotoxin on the engineered muscle tissue architecture and its subsequent effect on the passive tension. This simple yet effective tool can be appealing for studies that necessitate the analysis of skeletal muscle structure and function, including preclinical drug discovery and development.
工程化骨骼肌组织可用于需要生理相关的天然组织模型的体外研究。本文描述了一种三维（3D）骨骼肌组织的开发，该组织再现了肌肉在微流控装置内的结构和结构复杂性。我们使用 3D 光图案化方法，将细胞填充的明胶网络空间限制在两个生物惰性水凝胶柱周围，这两个水凝胶柱诱导细胞的单轴对齐，并作为封装细胞和肌肉组织的锚固点，因为它们形成和成熟。我们通过荧光显微镜和计算工具的组合，对细胞和骨骼肌组织形成过程中的组织形态和应变分布进行了表征。随时间变化的应变分布表明，在明胶基质内存在单个细胞，这些细胞分化为形成多核骨骼肌组织束，这是培养时间的函数。我们还开发了一种方法来计算悬挂在两个支柱之间的工程化肌肉组织束产生的被动张力。最后，作为概念验证，我们研究了骨骼肌芯片系统作为筛选平台和体外肌肉损伤模型的适用性。我们研究了心脏毒素对工程化肌肉组织结构的剂量依赖性影响及其对被动张力的后续影响。这个简单而有效的工具可能适用于需要分析骨骼肌结构和功能的研究，包括临床前药物发现和开发。
