Surface versus Nanocatalyst-Induced Matrix Bubbles Govern Temperature-Dependent Biofilm Removal

Bacterial biofilms protected by viscoelastic extracellular polymeric substances (EPS) are highly resistant to chemical disinfectants and rapidly regenerate after treatment. While bubble-mediated mechanical disruption has emerged as an eco-friendly antifouling strategy, bubbles generated by conventional tools act on biofilm surfaces and fail to disrupt three-dimensional biofilms. Here, we demonstrate that generating bubbles within biofilms, referred to as matrix bubbles, and controlling their dynamics with temperature, enables effective matrix disruption and biofilm removal. Using <i>P. aeruginosa</i> biofilms as a model system, we compared H₂O₂ alone with MnO₂ nanocatalyst-doped biosilica microparticles (MnO₂-biosilica) across a range of temperatures. H₂O₂ alone produced catalase-driven O₂ bubbles localized on the biofilm surface with minimal temperature dependence, resulting in limited biofilm removal. In contrast, MnO₂-biosilica generated temperature-amplified matrix bubbles that formed swarms, penetrated biofilms, disrupted EPS, and suppressed regrowth at elevated temperatures (25 and 40 °C). Kinetic and imaging analyses revealed that this temperature-dependent behavior arises from accelerated MnO₂-catalyzed H₂O₂ decomposition coupled with enhanced bubble expansion and rupture, which deliver strong mechanical perturbation within the biofilm matrix. Importantly, nanocatalyst-induced matrix bubbles effectively removed biofilm from complex surgical instrument geometries and acted synergistically with autoclaving. This study therefore establishes temperature-controlled, nanocatalyst-mediated matrix bubble dynamics as a physical strategy for overcoming biofilm resistance in clinical and industrial settings.