Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Lab Chip. 2012 Dec 7;12(23):4976-85. doi: 10.1039/c2lc40338b.
Densely arrayed skeletal myotubes are activated individually and as a group using precise optical stimulation with high spatiotemporal resolution. Skeletal muscle myoblasts are genetically encoded to express a light-activated cation channel, Channelrhodopsin-2, which allows for spatiotemporal coordination of a multitude of skeletal myotubes that contract in response to pulsed blue light. Furthermore, ensembles of mature, functional 3D muscle microtissues have been formed from the optogenetically encoded myoblasts using a high-throughput device. The device, called "skeletal muscle on a chip", not only provides the myoblasts with controlled stress and constraints necessary for muscle alignment, fusion and maturation, but also facilitates the measurement of forces and characterization of the muscle tissue. We measured the specific static and dynamic stresses generated by the microtissues and characterized the morphology and alignment of the myotubes within the constructs. The device allows testing of the effect of a wide range of parameters (cell source, matrix composition, microtissue geometry, auxotonic load, growth factors and exercise) on the maturation, structure and function of the engineered muscle tissues in a combinatorial manner. Our studies integrate tools from optogenetics and microelectromechanical systems (MEMS) technology with skeletal muscle tissue engineering to open up opportunities to generate soft robots actuated by a multitude of spatiotemporally coordinated 3D skeletal muscle microtissues.
使用具有高精度时空分辨率的精确光刺激，可以单独和集体激活密集排列的骨骼肌纤维。骨骼成肌细胞被遗传编码以表达光激活阳离子通道，即 Channelrhodopsin-2，这使得对脉冲蓝光有反应的大量骨骼肌纤维能够进行时空协调。此外，使用高通量装置从光遗传编码的成肌细胞中形成了成熟的、功能齐全的 3D 肌肉微组织。该装置称为“芯片上的骨骼肌”，不仅为成肌细胞提供了肌肉对齐、融合和成熟所需的受控应变和约束，还方便了力的测量和肌肉组织的特性分析。我们测量了微组织产生的特定静态和动态应力，并对构建体中的肌纤维的形态和排列进行了特征描述。该装置允许以组合方式测试广泛的参数（细胞来源、基质组成、微组织几何形状、辅助负载、生长因子和运动）对工程化肌肉组织的成熟度、结构和功能的影响。我们的研究将光遗传学和微机电系统（MEMS）技术的工具与骨骼肌组织工程相结合，为制造由大量时空协调的 3D 骨骼肌微组织驱动的软体机器人开辟了机会。
