Hollow Magnetic Nanocarrier-Based\nMicrorobot Swarms\nfor NIR-Responsive Targeted Drug Delivery and Synergistic Therapy

Nanocarriers are frequently used for drug delivery due\nto their\nlarge surface area, biocompatibility, and photothermal effects. However,\nthey face the problem of premature drug leakage during drug transport.\nTo address this challenge, we developed near-infrared light (NIR)-responsive\nhollow magnetic nanocarriers (HMC) by incorporating a chitosan-based\nmolecular valve onto hollow magnetic nanocarriers (CHMC) to enable\nNIR-triggered drug release. Despite this advancement, this material\nstill encounters the challenge of inadequate targeting. Recognizing\nthe efficacy of magnetically driven micro/nanorobot swarms in remote\nwireless control, targeted motion, and efficient transport, we merged\nCHMC with magnetically controlled micro/nanorobot swarms. We evaluated\ntheir performance under programmable magnetic fields, which can be\nprecisely controlled in biological fluid and directed toward targeting\ncells. Additionally, they demonstrated the ability to execute a responsive\ndrug release under NIR irradiation. Ultimately, we confirmed their\ncapacity for targeted delivery, responsive drug release, and photothermal\ntherapy for liver cancer treatment in vivo. This approach heralds\nnew possibilities for responsive drug therapy facilitated by micro/nanorobot\nswarms, offering promising advancements in medical treatment.