Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801;Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801;Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
Proc Natl Acad Sci U S A. 2014 Jul 15;111(28):10125-30. doi: 10.1073/pnas.1401577111. Epub 2014 Jun 30.
Combining biological components, such as cells and tissues, with soft robotics can enable the fabrication of biological machines with the ability to sense, process signals, and produce force. An intuitive demonstration of a biological machine is one that can produce motion in response to controllable external signaling. Whereas cardiac cell-driven biological actuators have been demonstrated, the requirements of these machines to respond to stimuli and exhibit controlled movement merit the use of skeletal muscle, the primary generator of actuation in animals, as a contractile power source. Here, we report the development of 3D printed hydrogel "bio-bots" with an asymmetric physical design and powered by the actuation of an engineered mammalian skeletal muscle strip to result in net locomotion of the bio-bot. Geometric design and material properties of the hydrogel bio-bots were optimized using stereolithographic 3D printing, and the effect of collagen I and fibrin extracellular matrix proteins and insulin-like growth factor 1 on the force production of engineered skeletal muscle was characterized. Electrical stimulation triggered contraction of cells in the muscle strip and net locomotion of the bio-bot with a maximum velocity of ∼ 156 μm s(-1), which is over 1.5 body lengths per min. Modeling and simulation were used to understand both the effect of different design parameters on the bio-bot and the mechanism of motion. This demonstration advances the goal of realizing forward-engineered integrated cellular machines and systems, which can have a myriad array of applications in drug screening, programmable tissue engineering, drug delivery, and biomimetic machine design.
将生物成分（如细胞和组织）与软机器人相结合，可以制造出能够感知、处理信号和产生力的生物机器。生物机器的直观演示是能够对外界可控信号做出响应并产生运动的机器。虽然已经展示了由心肌细胞驱动的生物执行器，但这些机器对刺激做出响应并表现出受控运动的要求使得需要使用骨骼肌作为可收缩的动力源，骨骼肌是动物产生运动的主要来源。在这里，我们报告了 3D 打印水凝胶“生物机器人”的开发，这些生物机器人具有不对称的物理设计，并由工程化的哺乳动物骨骼肌条的驱动来实现生物机器人的净运动。使用立体光刻 3D 打印优化了水凝胶生物机器人的几何设计和材料特性，并表征了胶原蛋白 I 和纤维蛋白细胞外基质蛋白以及胰岛素样生长因子 1 对工程化骨骼肌产生力的影响。电刺激引发肌肉条中细胞的收缩和生物机器人的净运动，最大速度约为 156 μm s(-1)，每分钟超过 1.5 个体长。建模和模拟用于理解不同设计参数对生物机器人的影响和运动机制。这一演示推进了实现正向设计的集成细胞机器和系统的目标，这些机器和系统在药物筛选、可编程组织工程、药物输送和仿生机器设计等方面具有广泛的应用前景。
