Dual-functional Laser-Guided Magnetic Nanorobot Collectives Against Gravity for On-demand Thermo-chemotherapy of Peritoneal Metastasis.

Combining hyperthermic intraperitoneal chemotherapy (HIPEC) with cytoreductive surgery is the main treatment modality for peritoneal metastatic (PM) carcinoma despite the off-target effects of chemotherapy drugs and ineluctable side effects of total abdominal heating. We herein report a laser-integrated magnetic actuation system that actively delivers doxorubicin (DOX)-grafted magnetic nanorobot collectives to the tumor site in model mice for local hyperthermia and chemotherapy. With intraluminal movements controlled by a torque-force hybrid magnetic field (TFMF), these magnetic nanorobots gathered at a fixed point coinciding with the position of the localization laser, moving upward against gravity over a long distance and targeting tumor sites under ultrasound imaging guidance. Because aggregation enhanced the photothermal effect, controlled local DOX release was achieved under near-infrared (NIR) laser irradiation. We demonstrated the targeted on-demand photothermal therapy (PTT) of multiple PM carcinomas while minimizing off-target tissue damage. Additionally, a localization/treatment dual-functional laser-integrated magnetic actuation system was developed and validated in vivo, offering a potentially clinically feasible drug delivery strategy for targeting PM and other intraluminal tumors. This article is protected by copyright. All rights reserved.