Ph.D. Research Proposal Exam: Ryan Huiszoon
Monday, June 18, 2018
1146 AV Williams Building
Title: Flexible Sensor Platform for Detection, Treatment, and Inhibition of Bacterial Biofilms in Cylindrical Environments
Candidate: Ryan Huiszoon
MEMS Sensors and Actuators Lab
Fischell Department of Bioengineering
Institute for Systems Research
Professor Reza Ghodssi (Chair)
Professor William Bentley
Professor Jim Culver
Professor Giuliano Scarcelli
Date/Time: Monday morning June 18, 2018 / 9:00 a.m. - 11 a.m.
Location: ISR Conference Room 1146 , AVW Building
Biofilms are sessile communities of bacteria living on a surface, encased in a protective matrix consisting primarily of polysaccharides and extracellular DNA. These aggregates present a significant challenge due to their increased tolerance to antibiotic therapy and resistance to removal via disinfectants compared to their planktonic counterparts. Biofilms form readily on medical device and implant surfaces, where they serve as a source of recurring infections even after the initial systemic infection has been cleared. Furthermore, biofilm colonization of hospital water systems can lead to infection outbreaks among vulnerable patients. While numerous device-based approaches for biofilm detection and treatment have been explored, a barrier to their implementation is the complexity of the environments where biofilms form. In particular, on-chip microelectrodes have been used to monitor biofilm growth via impedance. However, these rigid and planar platforms do not lend themselves to facile integration with the complex 3D geometry of the areas vulnerable to biofilm colonization. In this work, I propose to develop a flexible platform for in situ detection and treatment of bacterial biofilm in cylindrical environments. The first aim will consist of fabricating IDE electrodes on a flexible substrate, to allow the platform to conform to a cylindrical surface while maintaining functionality. In addition, the real-time detection of biofilm via impedance sensing using this platform will be evaluated, and wireless readout and control will be implemented. Preliminary work towards this aim includes successful fabrication via conventional microfabrication processes and a demonstration of impedimetric detection, where a sharp decrease in impedance corresponds to biofilm growth. Along with detection, this platform is also capable of biofilm treatment using the bioelectric effect. The bioelectric effect consists of a low-intensity electric field combined with a low dose of an antimicrobial to yield a synergistic reduction in biofilm compared to either element alone. The second aim will seek to characterize this effect in a cylindrical setting by examining the resulting viability, surface coverage, biomass, and mechanical properties of the treated biofilms. Furthermore, the impact of the curvature on device performance will be explored, varying from completely planar to a low-diameter catheter. The third and final aim will examine device performance in two disparate cylindrical settings which are susceptible to biofilm formation: a urinary catheter and a hospital water fixture. The predominant organisms, fluid compositions, and flow patterns are different in each of these applications. The impact on detection and treatment by varying each of these parameters will be determined, to demonstrate functionality in relevant environments. Successful completion of the proposed research will yield a platform for in situ biofilm detection and treatment which can be readily implemented in cylindrical settings. In addition, the approach will lay the foundation for developing additional devices for biofilm management in a diverse array of environments.