Micro/nanorobotic swarms consisting of numerous tiny building blocks show great potential in biomedical applications because of their collective active delivery ability, enhanced imaging contrast, and environment-adaptive capability. However, in vivo real-time imaging and tracking of micro/nanorobotic swarms remain a challenge, considering the limited imaging size and spatial-temporal resolution of current imaging modalities. Here, we propose a strategy that enables real-time tracking and navigation of a microswarm in stagnant and flowing blood environments by using laser speckle contrast imaging (LSCI), featuring full-field imaging, high temporal-spatial resolution, and noninvasiveness. The change in dynamic convection induced by the microswarm can be quantitatively investigated by analyzing the perfusion unit (PU) distribution, offering an alternative approach to investigate the swarm behavior and its interaction with various blood environments. Both the microswarm and surrounding environment were monitored and imaged by LSCI in real time, and the images were further analyzed for simultaneous swarm tracking and navigation in the complex vascular system. Moreover, our strategy realized real-time tracking and delivery of a microswarm in vivo, showing promising potential for LSCI-guided active delivery of microswarm in the vascular system.

中文翻译：

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激光散斑对比成像下的微群跟踪和导航，用于定向递送

由众多微小构件组成的微/纳米机器人群因其集体主动传递能力、增强的成像对比度和环境适应能力而在生物医学应用中显示出巨大的潜力。然而，考虑到当前成像方式的成像尺寸和时空分辨率有限，微/纳米机器人群的体内实时成像和跟踪仍然是一个挑战。在这里，我们提出了一种利用激光散斑对比成像（LSCI）对静止和流动血液环境中的微群进行实时跟踪和导航的策略，具有全场成像、高时空分辨率和非侵入性。通过分析灌注单元（PU）分布可以定量研究微群引起的动态对流变化，为研究微群行为及其与各种血液环境的相互作用提供了另一种方法。LSCI 对微群和周围环境进行实时监测和成像，并进一步分析图像，以便在复杂的血管系统中同时进行群跟踪和导航。此外，我们的策略实现了体内微群的实时跟踪和传递，显示出 LSCI 引导的微群在血管系统中主动传递的巨大潜力。