(197e) Advancing the Functionality of Dimethylallylamine-Based Nanocultures for Selective Transport and Controlled Microbial Dynamics.

The need for new assessment tools for microbial dynamics has necessitated the miniaturisation of cell-culturing techniques and the design of microsystems that facilitate the interrogation of microorganisms in-well-defined environments. The nanocultures, as described in this work, are a type of such assessment tool: nanolitre-sized microcapsules generated using a flow-focusing microfluidic device to sequester and cultivate microbes in a high-throughput manner. By manipulating the chemistry of their polymeric shell, the nanocultures can be designed to achieve new functionalities, such as a selective permeability facilitating the transport of metabolites, nutrients and other small molecules essential to control cell growth and characterize community dynamics. In this work, transport properties of a newly designed Poly(dimethylsiloxane)-based polymer membrane functionalized with Dimethylallylamine (DMAA) have been examined by investigating the diffusion of selected molecules relevant to controlling cell dynamics, including antimicrobials, fluorescent staining probes and sugars. Furthermore, the Flory-Huggins Interaction Parameter was evaluated as a predictive tool to elucidate the partitioning and transport of selected molecules into the nanocultures. Diffusion of molecules was confirmed experimentally by generating nanocultures containing Escherichia coli cells, whereby cell growth was used as a proxy for determination of successful molecule diffusion. These data will pave the way in our understanding of effectively using the nanocultures to study complex synergistic and antagonistic microbial behaviours in both natural and synthetic communities, with the goal of better simulating natural microenvironments and increasing discoverability of novel molecules such as antimicrobials.