Micro- and nanorobots excel in navigating the intricate and often inaccessible areas of the human body, offering immense potential for applications such as disease diagnosis, precision drug delivery, detoxification, and minimally invasive surgery. Despite their promise, practical deployment faces hurdles, including achieving stable propulsion in complex in vivo biological environments, real-time imaging and localization through deep tissue, and precise remote control for targeted therapy and ensuring high therapeutic efficacy. To overcome these obstacles, we introduce a hydrogel-based, imaging-guided, bioresorbable acoustic microrobot (BAM) designed to navigate the human body with high stability. Constructed using two-photon polymerization, a BAM comprises magnetic nanoparticles and therapeutic agents integrated into its hydrogel matrix for precision control and drug delivery. The microrobot features an optimized surface chemistry with a hydrophobic inner layer to substantially enhance microbubble retention in biofluids with multiday functionality and a hydrophilic outer layer to minimize aggregation and promote timely degradation. The dual-opening bubble-trapping cavity design enables a BAM to maintain consistent and efficient acoustic propulsion across a range of biological fluids. Under focused ultrasound stimulation, the entrapped microbubbles oscillate and enhance the contrast for real-time ultrasound imaging, facilitating precise tracking and control of BAM movement through wireless magnetic navigation. Moreover, the hydrolysis-driven biodegradability of BAMs ensures its safe dissolution after treatment, posing no risk of long-term residual harm. Thorough in vitro and in vivo experimental evidence demonstrates the promising capabilities of BAMs in biomedical applications. This approach shows promise for advancing minimally invasive medical interventions and targeted therapeutic delivery.

中文翻译：

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成像引导的生物可吸收声学水凝胶微型机器人


微型和纳米机器人擅长在人体复杂且通常无法进入的区域导航，为疾病诊断、精准给药、排毒和微创手术等应用提供了巨大的潜力。尽管前景广阔，但实际部署面临障碍，包括在复杂的体内生物环境中实现稳定推进、通过深部组织进行实时成像和定位，以及精确远程控制靶向治疗和确保高治疗效果。为了克服这些障碍，我们推出了一种基于水凝胶、成像引导、生物可吸收声学微型机器人 （BAM），旨在以高度稳定性导航人体。BAM 采用双光子聚合构建，由磁性纳米颗粒和治疗剂组成，集成到其水凝胶基质中，用于精确控制和药物递送。该微型机器人具有优化的表面化学成分，具有疏水内层，可显着增强生物流体中的微气泡保留，具有多日功能，亲水外层可最大限度地减少聚集并促进及时降解。双开口气泡捕获腔设计使 BAM 能够在一系列生物流体中保持一致和高效的声学推进。在聚焦超声刺激下，被捕获的微泡振荡并增强实时超声成像的对比度，从而通过无线磁导航促进对 BAM 运动的精确跟踪和控制。此外，BAMs 的水解驱动生物降解性确保其在处理后安全溶解，不会造成长期残留危害的风险。 全面的体外和体内实验证据表明 BAM 在生物医学应用中具有广阔的潜力。这种方法有望推进微创医疗干预和靶向治疗。