Developing a Functional Microbial Nanoculture System to Assess the Growth Dynamics of S. Aureus and P. Aeruginosa

A countless number of microorganisms comprise our microbiome. Understanding the interactions among these microbes, however, is precluded by their inability to be cultured for observation in a lab with current technology. We are developing a microfluidic-based technology to study microbial dynamics in controlled environments. Microfluidic encapsulation within a semipermeable polymer shell, referred to as the nanocultures, enables observation of interactions between microorganisms and allows pressure and nutrient control over culture environment. Previously, we created a microfluidic encapsulation system and determined favorable compositions of the biocompatible Poly(dimethylsiloxane) (PDMS). Here, we present the study of Pseudomonas aeruginosa and Staphylococcus aureus, two prevalent bacterial species in patients having cystic fibrosis, grown and observed within a nanoculture. The mechanical properties of this membrane, PDMS functionalized by N,N-Dimethylacrylamide (DMA), were studied to determine the transport properties. Tensile strength testing was performed to determine the elasticity of the cured membranes with varying concentrations of DMA. Osmotic annealing experiments yielded insight into the curing dependency on heat pretreatment and pressure gradient response. Finally, P. aeruginosa and S. aureus were grown and observed in a stable microenvironment for 24 hours. These advancements in the observation of two pathogenic bacteria present numerous opportunities for future work.