School of Mechatronic Engineering and Automation, Shanghai University, Shanghai, China.
J Mater Chem B. 2023 Jul 5;11(26):6095-6105. doi: 10.1039/d3tb00852e.
Microrobots for targeted drug delivery in blood vessels have attracted increasing interest from researchers. In this work, hydrogel-based capsule microrobots are used to wrap drugs and deliver drugs in blood vessels. In order to prepare capsule microrobots of different sizes, a triaxial microfluidic chip is designed and built, and the formation mechanism of three flow phases including the plug flow phase, bullet flow phase and droplet phase during the preparation of capsule microrobots is studied. The analysis and simulation results show that the size of the capsule microrobots can be controlled by the flow rate ratio of two phases in the microfluidic chip, and when the flow rate of the outer phase is 20 times that of the inner phase in the microfluidic chip, irregular multicore capsule microrobots can be prepared. On this basis, a three degree of freedom magnetic drive system is developed to drive the capsule microrobots to reach the destination along the predetermined trajectory in the low Reynolds number environment, and the magnetic field performance of the magnetic drive system is simulated and analyzed. Finally, in order to verify the feasibility of targeted drug delivery of the capsule microrobots in the blood vessel, the motion process of the capsule microrobots in the vascular microchannel is simulated, and the relationship between the motion performance of the capsule microrobots and the magnetic field is studied. The experimental results show that the capsule microrobots can reach a speed of 800 μm s at a low frequency of 0.4 Hz. At the same time, the capsule microrobots can reach a peak speed of 3077 μm s and can continuously climb over a 1000 μm high obstacle under a rotating magnetic field of 2.4 Hz and 14.4 m. Experiments show that the capsule microrobots have excellent drug delivery potential in similar vascular curved channels driven by this system.
用于血管内靶向药物输送的微机器人引起了研究人员越来越多的兴趣。在这项工作中，水凝胶胶囊微机器人用于包裹药物并在血管内输送药物。为了制备不同尺寸的胶囊微机器人，设计并构建了三轴微流控芯片，并研究了在制备胶囊微机器人过程中包括塞流相、子弹流相和液滴相的三相形成机制。分析和模拟结果表明，胶囊微机器人的尺寸可以通过微流控芯片中两相的流速比来控制，当微流控芯片中外相的流速是内相的 20 倍时，可以制备出不规则多核胶囊微机器人。在此基础上，开发了一种三自由度磁驱动系统，以驱动胶囊微机器人在低雷诺数环境中沿着预定轨迹到达目的地，并对磁驱动系统的磁场性能进行了模拟和分析。最后，为了验证胶囊微机器人在血管内靶向药物输送的可行性，模拟了胶囊微机器人在血管微通道中的运动过程，并研究了胶囊微机器人的运动性能与磁场之间的关系。实验结果表明，胶囊微机器人在 0.4 Hz 的低频下可以达到 800 μm s 的速度。同时，胶囊微机器人在 2.4 Hz 和 14.4 m 的旋转磁场下可以达到 3077 μm s 的峰值速度，并可以连续爬过 1000 μm 高的障碍物。实验表明，在该系统驱动下，胶囊微机器人在类似的血管弯曲通道中具有优异的药物输送潜力。
