Mechanochemical Nanozyme Microbots Overcome Biofilm Barriers for Antibiotic-Free Therapy of Chronic Infections.

A major challenge in biofilm-associated infection therapy is overcoming biofilm barriers while eradicating embedded bacteria without inducing antibiotic resistance. Here, we report an antibiotic-free microbotic platform that synergistically integrates magnetomechanical biofilm disruption with localized nanozyme-mediated bactericidal activity, enabling efficient and biocompatible biofilm eradication in vivo. Under a rotating magnetic field, nanozyme microbots transition from individual spinning to reconfigurable vortex swarming, generating strong local fluid shear forces that mechanically disrupt the extracellular polymeric substance matrix and drive deep penetration into biofilms. Within the disrupted biofilm, the Fe3O4 nanozyme cores catalyze endogenous H2O2 to produce bactericidal hydroxyl radicals, resulting in effective elimination of both Gram-positive and Gram-negative bacteria. In murine biofilm infection models, the nanozyme microbots significantly reduce the bacterial burden, accelerate wound closure, suppress inflammation, and promote angiogenesis. This work establishes a mechanochemical microbotic strategy that combines programmable swarm dynamics with nanozyme catalysis, providing a promising antibiotic-independent approach to treating chronic biofilm-associated infections.