Micro/nanomotors for biofilm inhibition: insights into propulsion modes, biofilm interactions, design strategies and translational challenges

Bacterial biofilms present a major challenge to traditional antimicrobial therapies because of their dense extracellular polymeric substance (EPS) matrix, metabolic heterogeneity, and intrinsic resistance mechanisms, which severely limit drug penetration and efficacy. Recent progress in micro/nanomotors (MNMs) has opened new opportunities for the successful delivery of therapeutics to the complex biofilm microenvironment by penetration and disruption. Here, the recent progress in MNM systems designed to tackle biofilm-associated problems, with particular emphasis on propulsion strategies that enable effective operation within the viscous and heterogeneous biofilm microenvironment, is summarised. Importantly, this review highlights the relationship between the physicochemical properties of the MNMs and the biofilm microenvironment factors influencing them. Also, the recent in vivo studies of MNMs, offering valuable perspectives on the translational potential of these systems for prospective clinical applications, are presented in detail. Finally, the current challenges and future directions for the rational design of MNMs to manage biofilm infections are outlined.