image: (A) Schematic of a Jablonski diagram. (B) Fabrication and fluorescent pictures of MNMs with NIR-797 dyes. (C) Preparation and fluorescent pictures of QD-based MNMs. (D) Preparation and fluorescent pictures of bioautofluorescent MNMs.
Credit: Lei Wang, School of Chemistry and Chemical Engineering, Harbin Institute of Technology.
Recent research led to impactful achievements in advanced imaging strategies using intelligent micro/nanomotors (MNMs), which offer transformative solutions to traditional bioimaging paradigms by enabling enhanced detection sensitivity and real-time tracking of subcellular events and microenvironmental changes. Nevertheless, full realization of deep-tissue imaging and high resolution remains challenging to achieve, often limited by inherent constraints such as poor penetration depth and signal degradation. Based on research experience in this field, the study first summarizes the signal-enhancing mechanisms of MNMs in single-modal imaging, explores multimodal applications through MNMs-probe design, and discusses artificial intelligence-driven intelligent MNMs for precision imaging. "This integrated approach will make bioimaging technologies more effective, overcoming limitations in spatiotemporal resolution and providing a theoretical framework and research roadmap for MNMs-mediated bioimaging technologies," said authors. Thus, they proposed imaging strategies that integrate MNMs as dynamic contrast agents, featuring autonomous propulsion and multifunctional features to enhance ultrasound, fluorescence, photoacoustic, and magnetic resonance imaging.
MNMs can be designed by using multiple materials and fabrication processes, ranging from organic dyes to quantum dots, and leveraging driving modes such as magnetic, light, or chemical energy. These methods bring significant benefits in design and application, making it easy to introduce active targeting within complex biological environments, enhancing signal amplification, and reducing background noise. "MNMs act as multifunctional platforms for integrating diverse imaging modalities, enabling multimodal diagnostics and bridging diagnostic imaging with targeted therapy," said authors. The study showed that MNMs-based imaging systems are developed at reduced effort and time, using advanced strategies like spectral engineering and swarm intelligence. The controllers, while adaptive, keep imaging signals stable, even in the presence of biological barriers. The imaging systems demonstrated dexterity and capability to track targets with different depths, resolutions, and functionalities.
"The autonomous motion and precise control guarantee actuator’s penetration and consequently enhanced imaging depth when navigating within organisms. The imaging strategies achieved an impressive sensitivity level, being able to detect objects of different shapes and sizes at subcellular levels. Nevertheless, it struggles with deeper tissue penetration due to motion-related challenges, showing concentrated signal loss in high-viscosity media while control precision is constrained. In addition, depending on the imaging modality, there exists interference from background noise or off-target deposition. Since MNMs are highly complex, with most variables of interest being coupled between themselves, future work will be dedicated to an in-depth analysis of motion behavior and control mechanisms together with further optimization of biocompatibility and degradability," said authors. Totally, this MNMs-enhanced imaging is accessible and can be implemented at a reduced cost, avoiding time-consuming trial-and-error processes, and inspiring innovation in biomedical diagnostics.
Authors of the paper include Dang Zhang, Liang Lin, Chao Deng, Mohamed Syazwan Osman, Paul E.D. Soto Rodriguez, Fei Han, Mingyu Li, and Lei Wang.
The authors appreciate the funding from NSFC (Nos. 52473109 and 61705070), the Foundation of Wenzhou Basic Scientific Research Project (Y20240005), the Huzhou Science and Technology Plan Project (Grant No. 2024GZ52), and the China–Bulgaria Mobility project from the Ministry of Science and Technology of China (L.W.). P.E.D.S.R. acknowledges the financial support from the Spanish Ministry of Economy and the Canary Islands program Viera y Clavijo Senior (Ref. 2023/00001156), the University of La Laguna “Noveles investigadores (Exp. 2024/2760)”, and Project (ProID2024010032) financed by “Agencia Canaria de Investigación Innovación y Sociedad de la Información (ACIISI)” and by “Fondo Europeo de Desarrollo Regional” in the framework of the Canarian FEDER Program 2021-2027. M.S.O. acknowledges the financial support from Fundamental Research Grant Scheme (Grant No. FRGS/1/2022/STG05/UITM/02/10).
The paper, “Advanced Imaging Strategies Based on Intelligent Micro/Nanomotors” was published in the journal Cyborg and Bionic Systems on Sep 10, 2025, at DOI: 10.34133/cbsystems.0384.
Journal
Cyborg and Bionic Systems