Therapeutic-scale CAR-NK microrobots with programmable swarm navigation for targeted solid tumor therapy.

CAR-NK cells loaded with magnetic nanoparticles become biohybrid microrobots that can be magnetically navigated to tumors at therapeutic doses in mice and nonhuman primates in vivo. Programmable magnetic fields switch their swarms between vortex mode for long-distance targeted transport and ribbon mode for broad dispersion over the target site. In metastatic leptomeningeal carcinomatosis, intrathecal injection followed by magnetic guidance through the spinal canal delivered the microrobots to the brain's cerebrospinal fluid space, with real-time angiographic imaging confirming navigation in a nonhuman primate model.