Non-technical: This NSF/FDA Scholar-in-Residence award by the Biomaterials program in the Division of Materials Research to the University of Arkansas is to develop a microdialysis sampling system to assess the localized chemistry associated with biofilm/polymer interfaces. Biofilms are complex chemical matrices produced by communities of bacteria. In a biofilm, free-floating bacteria begin to form a community of bacteria and start synthesizing specialized chemical matrices in support of this bacterial community. The bacteria in the biofilm are far more antibiotic-resistant than the free-floating ones, and the biofilm formation adds enormous costs to healthcare and various industries. There is considerable interest in the improvement of scientific methods for early biofilm detection and its eradication. Bacteria communicate with each other through the biofilm via a process called quorum sensing. In quorum sensing, chemicals unique to the bacterial species are released, and 'talk' to each others present in the surrounding medium. This project will use the microdialysis sampling approach to collect the quorum sensing chemicals from the bacterial/material interface. The broader impact of the project is in the early detection of the biofilm formation on medical devices, and possible development of treatments to control the biofilm formation. The proposed approaches also could allow the implementation of various treatments to see how these affect the bacterial community, chemical communication and the biofilm structure.
The primary goal for this NSF/FDA Scholar-in-Residence award is to create a dual culture system with microdialysis sampling that incorporates medically-relevant bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis) and macrophages (RAW 267.4). Microdialysis sampling provides a unique platform to quantify localized chemistry in situ at the bacterial colonization/material interface. Aim 1 of the project seeks to develop the microdialysis sampling/biofilm interface. In Aim 2, localized pH changes and quorum sensing signals will be quantified in real-time during the biofilm colonization process onto the dialysis polymeric membrane. Aim 3 seeks to develop a biofilm/macrophage co-culture system to address needed challenges in understanding initial host response to bacterial biofilms. Building on the strength of the investigator with macrophage biology and associated cytokine signaling measurements using microdialysis, Aim 3 will develop a system to determine system parameters and signaling output that affect the combination of macrophage cells and bacteria. The successful outcomes of this proposed work include: 1) A rapid and interchangeable method to assess how different prophylactic treatments affect biofilm formation and quorum sensing. 2) A method to assess the temporal chemical dynamics associated with biofilm formation thus allowing important basic science studies to affect various checkpoints in the biofilm process. 3) An easy-to-use, robust and laboratory transferrable basic science method for monitoring various aqueous chemical aspects of interfacial biofilm chemistry. 4) A novel co-culture system to begin to assess the dynamic role of the localized immunological response, particularly macrophages, toward fighting and/or eliminating the initial formation of a bacterial colony and thus associated biofilm and infection. 5) Potential for in vitro to in vivo translation.