Andrew and Peggy Cherng Department of Medical Engineering, California Institute of Technology, Pasadena, CA, USA.
Chem Soc Rev. 2020 Nov 21;49(22):8088-8112. doi: 10.1039/d0cs00309c. Epub 2020 Jun 29.
Medical micro/nanorobots have received tremendous attention over the past decades owing to their potential to be navigated into hard-to-reach tissues for a number of biomedical applications ranging from targeted drug/gene delivery, bio-isolation, detoxification, to nanosurgery. Despite the great promise, the majority of the past demonstrations are primarily under benchtop or in vitro conditions. Many developed micro/nanoscale propulsion mechanisms are based on the assumption of a homogeneous, Newtonian environment, while realistic biological environments are substantially more complex. Moving toward practical medical use, the field of micro/nanorobotics must overcome several major challenges including propulsion through complex media (such as blood, mucus, and vitreous) as well as deep tissue imaging and control in vivo. In this review article, we summarize the recent research efforts on investigating how various complexities in biological environments impact the propulsion of micro/nanoswimmers. We also highlight the emerging technological approaches to enhance the locomotion of micro/nanorobots in complex environments. The recent demonstrations of in vivo imaging, control and therapeutic medical applications of such micro/nanorobots are introduced. We envision that continuing materials and technological innovations through interdisciplinary collaborative efforts can bring us steps closer to the fantasy of "swallowing a surgeon".
医学微/纳机器人在过去几十年中受到了极大的关注，因为它们有可能被引导到难以到达的组织中，用于多种生物医学应用，从靶向药物/基因传递、生物隔离、解毒到纳米手术。尽管前景广阔，但过去的大多数演示主要是在台架或体外条件下进行的。许多已开发的微/纳尺度推进机制基于对均匀、牛顿环境的假设，而现实生物环境要复杂得多。为了推向实际的医疗应用，微/纳机器人领域必须克服几个主要挑战，包括在复杂介质（如血液、粘液和玻璃体）中推进，以及在体内进行深层组织成像和控制。在这篇综述文章中，我们总结了最近研究如何研究生物环境中的各种复杂性如何影响微/纳米游泳者的推进的研究工作。我们还强调了新兴的技术方法，以增强微/纳米机器人在复杂环境中的运动能力。介绍了这些微/纳米机器人在体内成像、控制和治疗医学应用方面的最新演示。我们设想，通过跨学科合作的持续材料和技术创新，可以使我们更接近“吞下一名外科医生”的幻想。
