Magnetic Field-Driven Strategies for Biofilm Disruption: From Iron Oxide Nanoparticles to Adaptive Swarms of Magnetic Microrobots

Biofilms, structured communities of microbial cells embedded in extracellular polymeric substances, are notorious for their resilience against conventional antimicrobial treatments. They contribute significantly to chronic infections and industrial biofouling, necessitating innovative strategies for their eradication. Magnetic iron oxide nanoparticles have emerged as a promising tool in combating biofilms due to their biocompatibility and unique physicochemical properties, which enable magnetic delivery of antibacterial agents, magnetic hyperthermia, magneto-mechanical actuation including mechanical biofilm disruption, and reversible dynamic magnetic assembly into hierarchical structures. This review describes developing stages of magnetic nanoscale weapons against biofilms ranging from individual iron oxide nanoparticles to complex hierarchical nanoparticle assemblies in the form of magnetic robots and their swarms. A vast array of possible antibiofilm and antibacterial functionalities originating from iron ions, individual iron oxide nanoparticles, spherical nanoparticle assemblies, magnetic robots, and swarms of robots are presented. Magnetic nanotools offer significant improvements and advantages over conventional methods for biofilm eradication, yet their successful future applications depend on addressing and overcoming critical material, biological, and engineering challenges.