Chemically-Driven Particle Penetration into Bacterial Biofilms

Bacterial biofilms are detrimental to human health. Their defining feature is a three-dimensional extracellular polymer matrix that presents a mechanical barrier to the transport of chemicals, such as antimicrobials, making them robust and difficult to remove. Targeting the disruption of the extracellular polymer matrix for increasing the susceptibility of the biofilm to antimicrobials is a promising but relatively unexplored approach to biofilm control and management. In this regard, the development of micro- and nanoparticles has offered new ideas for the management and eradication of bacterial biofilms. Hence, controlling and enhancing the transport of micro- and nanoparticle carriers in a biofilm's extracellular polymer matrix may have significant implications for how to approach the management and eradication of biofilms. In this work, we investigate externally imposed chemical gradients as a mechanism of transport of polystyrene particles into bacterial biofilms. We show how it is possible to transport particles into a biofilm matrix through imposed chemical gradients and discuss the dynamics and complexity in motion that arise due to the presence of the biofilm matrix. Our results demonstrate the importance of chemical species in disrupting the biofilm matrix and regulating particle transport in macromolecularly crowded environments. The results suggest potential applications in the transport and delivery of particles in physiologically relevant and macromolecularly crowded environments.