Real-time near-infrared II fluorescence navigation of magnetic nanorobots for image-guided therapy

Sep 28, 2026

Uploaded by nayy☆

Real-time navigation of magnetic nanorobots with high spatiotemporal resolution and molecular contrast in deep tissues remains difficult. The work develops near-infrared II (NIR-II; 1000–3000 nm) magnetic nanorobots balancing fluorescence brightness near 1600 nm with magnetic strength for precise locomotion in live mice under real-time imaging guidance. A two-plex NIR-II scheme enables molecular-specific localization of nanorobots and target sites, supports stability in simulated gastric conditions for over 2 weeks, and improves targeted delivery and therapy for inflammatory bowel disease.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Introduction

Challenges in real-time in vivo navigation of micro/nanorobots

Imaging modalities for tracking nanorobots in vivo

Rationale for NIR-II fluorescence guidance and study approach

APPLIED SCIENCES AND ENGINEERING Real-time near-infrared II fluorescence navigation of magnetic nanorobots for image-guided therapy Zideng Dai1†, Zhisheng Wu1,2†, Wayne Jason Li3†, Sixin Xu1, Danyang Xu1, Puxian Xiong1, Zhexi Liu1,2, Chuang Zhang4, Liangqiong Qu5, Lianqing Liu4*, Feifei Wang1,2* Real-time navigation of nanorobots with high spatiotemporal resolution and molecular contrast in deep tissues via noninvasive manners has been challenging. Here, we developed near-infrared II (NIR-II; 1000 to 3000 nanometers) magnetic nanorobots that balance fluorescence brightness at ~1600 nanometers with magnetic strength, facilitating precise gathering or locomotion of the nanorobots in the peritoneal cavity, hindlimb, liver, spleen, and lower gastrointestinal tract of live mice under real-time NIR-II imaging guidance with high resolution and sensitivity. Two-plex NIR-II imaging enabled precise locomotion by simultaneously providing real-time information on both the location of nanorobots and the position of target sites with molecular specificity. NIR-II magnetic nanorobots remained stable in gastric juice simulated solution (pH = 2) for more than 2 weeks. The magnetic locomotion of nanorobots loaded with 5-aminosalicylic acid under NIR-II visual feedback enables targeted delivery to the lower gastrointestinal tract and effectively enhances therapeutic efficacy in mice with inflammatory bowel disease. This platform opens an avenue in precision medicine. copyright © 2026 the Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. no claim to original U.S. Government Works. Distributed under a creative commons Attribution noncommercial license 4.0 (cc BY-nc) . INTRODUCTION Micro/nanorobots (MNRs) have the potential to be precisely navigated to targeted locations in live tissues that are difficult to assess by other methods, driving widespread exploration for applications in targeted drug delivery (1), disease diagnosis and treatment (2), and minimally invasive surgery (3). They can achieve autonomous locomotion by deriving energy from internal or external sources through various actuation mechanisms (4–6), including chemical/biochemical (7, 8), physical field (9, 10), and biological actuation ( 11) . Realtime visual feedback with a high resolution, molecular sensitivity, and deep tissue penetration capabilities is crucial for achieving accurate locomotion and high delivery efficiency and ensuring the biomedical safety of MNRsin complex in vivo environments (12, 13) . To date, magnetic resonance imaging (MRI) (14), computed tomography (CT) (15), positron emission tomography (PET) (16), ultrasound imaging (17, 18), photoacoustic imaging (19), laser speckle contrast imaging (LSCI) (4), and visible fluorescence imaging (20, 21) have been attempted to observe MNRs in vivo. MRI, CT, and PET enable deep tissue penetration; however, they are challenging for monitoring MNRs in real time over the long term due to limited temporal resolution (MRI) or a high risk of radiation-induced damage (CT and PET). Ultrasound and photoacoustic imaging are safe, but distinguishing MNRs from background tissue signals remains challenging (9, 19, 22, 23). LSCI primarily reflects surgeryexposed blood vessels in superficial tissues, providing strong imaging signals in vessels, which limits its ability to assess MNRs in deep organs noninvasively (24) and reduces sensitivity to MNR detection (4). Fluorescence imaging offers molecular sensitivity and high 1Jc SteM lab of nanoscience and nanomedicine, Department of electrical and electronic engineering, School of Biomedical engineering, the University of hong Kong, hong Kong SAR, china. 2Materials innovation institute for life Sciences and energy (MileS), the University of hong Kong-SiRi, Shenzhen, china. 3Department of Mechanical engineering, the University of hong Kong, hong Kong SAR, china. 4State Key laboratory of Robotics, Shenyang institute of Au

FAQs

Why is real-time navigation of magnetic nanorobots in deep tissues challenging?

Monitoring nanorobots in vivo requires high spatiotemporal resolution and molecular contrast, while many imaging methods struggle with real-time long-term monitoring, penetration, or background signal discrimination.

What imaging strategy enables precise locomotion of the nanorobots?

Near-infrared II (NIR-II) two-plex imaging provides real-time information on both the nanorobot location and the target-site position with molecular specificity.

How does the NIR-II magnetic nanorobot platform improve therapy in inflammatory bowel disease models?

NIR-II magnetic locomotion with visual feedback supports targeted delivery to the lower gastrointestinal tract, enhancing therapeutic efficacy in mice with inflammatory bowel disease.

Sep 28, 2026

Uploaded by nayy☆