(225e) Self-Locomotive Antimicrobial Microparticles for Enhanced Biofilm Removal

Biofilms are communities of bacterial cells that can cause a variety of healthcare problems. In particular, over 80% of microbial infections in human body is associated with bacterial biofilms, according to a survey from the US National Institutes of Health (NIH). However, traditional antibiotics treatments are not effective enough to remove the wound biofilm because the extracellular polymeric substances (EPS) can impede the diffusion of antibiotics into the biofilm. In this work, we developed a self-locomotive antimicrobial microparticle that can effectively remove biofilms through continuous bubble generation in an antiseptic H₂O₂ solution. We hypothesized that the microparticles' continuous bubble generation would deform the EPS matrix and ultimately abrade biofilms due to the repeated bubble expansion and burst. To examine this hypothesis, we firstly improved our previously developed diatom mircrobubbler by increasing the loading mass of manganese oxide (MnO₂) via polydopamine (PDA) coating. Then, we assessed and compared their self-locomotive capability by examining the propulsion speed and kinetic reaction in the H₂O₂ solution. Using Pseudomonas aeruginosa (P. aeruginosa) biofilm formed in microgrooves of a silicon substrate, we examined the extent that MnO₂ nanocatalyst mass per diatom modulates the abrasion of biofilms. In the end, we evaluated the biofilm removal efficacy by treating P. aeruginosa biofilms with minimal biofilm eradication concentration (MBEC) assay.