Abstract

Conventional drug delivery routes, such as oral and injectable administration, often suffer from poor targeting, systemic sideeffects, and limited control over drug release. Magnetically guided microrobots have emerged as a promising solution by enablingminimally invasive navigation, precise localization, and controllable cargo delivery in complex biological environments. Recentadvances in microfabrication, biomaterials, and magnetic actuation have led to diverse microrobot designs, including helicalswimmers and biohybrid systems incorporating red blood cells, bacteria, algae, or exosomes. These microrobots can transportdrugs, cells, or theranostic agents, with release triggered by magnetic, chemical, optical, or acoustic stimuli. In parallel, progressin imaging and tracking technologies, such as ultrasound, photoacoustic imaging, X-ray, and MRI, has enabled real-time guidanceand monitoring in vivo. Despite encouraging proof-of-concept studies, several challenges hinder clinical translation. These includelimited biocompatibility, reduced locomotion efficiency under physiological flow, insufficient release precision, and regulatoryconstraints. Future development requires safer and more robust materials, multimodal imaging strategies for accurate navigation,and scalable fabrication methods that meet medical standards. With continued integration of engineering and biomedical research,magnetically guided microrobots hold strong potential for targeted therapy, regenerative medicine, and minimally invasivetreatment, representing a significant advance in precision drug delivery.

Figure 1 Conceptual illustration of magnetically guided microrobots for targeted drug delivery. Conventional administration routes (oral andinjectable) often result in systemic circulation with limited targeting efficiency and off-target effects. Precise therapeutic delivery remains challengingin hard-to-reach pathological regions. Magnetically guided microrobots offer a next-generation solution by enabling minimally invasive navigation,spatiotemporally controlled drug or cell release, and real-time tracking, thereby addressing critical limitations of conventional therapies. MNPs: magneticnanoparticles.Created with BioGDP.com

Figure 2 Examples of Bioinspired Microrobots. (A) Schematic of the ABF microrobots system.Created with BioGDP.com. The ABFs rotateand propel by special rotating magnetic fields. (B) Magnetic nanoparticles (MNPs) aligned into magnetosome-like chain structures within microgelshells under a static magnetic field, while the BMM exhibited rapid and precisely positioned motion by rotating magnetic fields. (C) Actuation principleof the ciliary microrobot. Net displacement results from non-axially symmetric cilia beating by stepping magnetic fields. (D) Schematic of the bioinspiredfish microrobot with segmented Au/Ni/Silver architecture. Propulsion via tail undulation driven by planar oscillating magnetic fields.

https://doi.org/10.1002/adhm.202505942