2026-02-02 カリフォルニア工科大学（Caltech）
The scientists created two different types of bubble bots. Those illustrated at the top of this image are modified with magnetic nanoparticles and directed toward a tumor target with external magnets. The bots illustrated at the bottom have different enzymes bonded to the surface and follow a chemical gradient to locate the tumor target independently.Credit: Gao Lab/Caltech
＜関連情報＞
- https://www.caltech.edu/about/news/bubble-bots-simple-biocompatible-microrobots-autonomously-target-tumors
- https://www.nature.com/articles/s41565-025-02109-6
- https://www.science.org/doi/10.1126/scirobotics.adp3593
酵素マイクロバブルロボット Enzymatic microbubble robots
Songsong Tang,Hong Han,Xiaotian Ma,Payal N. Patel,Chen Gong,Junhang Zhang,Ernesto Criado-Hidalgo,Jounghyun Yoo,Jiahong Li,Gwangmook Kim,Shukun Yin,Di Wu,Mikhail G. Shapiro,Qifa Zhou & Wei Gao
Nature Nanotechnology Published:02 February 2026
DOI:https://doi.org/10.1038/s41565-025-02109-6
Abstract
The development of micro- and nanorobots has amplified the demand for intelligent multifunctional machines in biomedical applications, but most microrobotic systems struggle to achieve the attributes needed for those applications. Here we introduce enzymatic microbubble robots that exhibit steerable motion, enhanced biodegradability, high in vivo imaging contrast, and effective targeting and penetration of disease sites. These microrobots feature natural protein shells modified with urease to decompose bioavailable urea for autonomous propulsion, whereas an internal microbubble serves as an ultrasound imaging contrast agent for deep tissue imaging and navigation. Magnetic nanoparticle integration enables imaging-guided magnetically controlled motion and catalase functionalization facilitates chemotactic movement towards hydrogen peroxide gradients, directing robots to tumour sites. Focused ultrasound triggers robot shell collapse and inertial cavitation of the released microbubbles, creating mechanical forces that enhance therapeutic payload penetration. In vivo studies validate the tumour-targeting and therapeutic efficacy of these robots, demonstrating enhanced antitumour effects. This multifunctional microbubble robotic platform has the potential to transform medical interventions and precision therapies.
イメージング誘導型生体吸収性音響ハイドロゲルマイクロロボット Imaging-guided bioresorbable acoustic hydrogel microrobots
Hong Han, Xiaotian Ma, Weiting Deng, Junhang Zhang, […] , and Wei Gao
Science Robotics Published:11 Dec 2024
DOI:https://doi.org/10.1126/scirobotics.adp3593
Editor’s summary
Microrobots offer several opportunities in medicine for the diagnosis and treatment of various complications. However, there are several challenges related to their efficacy and ability to be detected in real time when deployed within the body. Han et al. have now developed bioresorbable acoustic microrobots that can be propelled acoustically and magnetically to tissues of interest and used for real-time ultrasound imaging and delivery of therapeutics. The gas-filled acoustic microrobots were used in vivo in a murine bladder tumor model and demonstrated the potential to support real-time imaging and delivery of anticancer drugs to the diseased tissue, resulting in the reduction in tumor size. —Amos Matsiko
Abstract
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.
