(7b) Designing Novel Surfaces to Control the Fate of Attached Microbes

Designing novel surfaces to control the fate of attached microbes

Huan Gu, Ph.D.

Research Assistant Professor

Department of Biomedical and Chemical Engineering and Syracuse Biomaterials Institute, Syracuse, NY 13244, USA

Research Interests: Bacteria can be found virtually everywhere. As one of the living styles, bacteria settle onto biotic or abiotic surfaces and form communities that are called biofilms. Biofilms are the leading cause of chronic infections in humans and persistent biofouling and biocorrosion in the industry, both of which are costing the United States billions of dollars annually. Biofilms also harbor ‘good’ bacteria to assist human activities, for instance, wastewater treatment. A crucial part of biofilm formation is surface property (e.g., surface chemistry, topography, and charge) in which determines bacterial adhesion and the physiology/fate of attached bacterial cells. My research program exploits fundamental knowledge of the physiological response of bacteria to surface property to develop novel surfaces that either minimize the adhesion of ‘bad’ bacteria (e.g., multi-drug resistant pathogens) or optimize beneficial biofilms to serve our purposes better. The outcomes of my research will accelerate the control of biofilm-associated high drug resistance, hospital-acquired infections, as well as persistent biofouling and biocorrosion.

Research Experience: With a multidisciplinary background in biofilm engineering, materials and surface engineering, and biotechnology, I have investigated how to control biofilm formation and associated drug resistance by modifying surface property, and how biofilms are involved in hospital-acquired infections. During my graduate program, I established a well-defined surface system using chemical surface modification for the mechanistic understanding of biofilm formation and associated antibiotic resistance. The obtained results together with the effects of surface topography on bacterial adhesion were used to engineer ‘smart’ antifouling surfaces via topographic surface modification. My postdoctoral training builds upon my prior experience to control biofilm-associated hospital-acquired infections. I have gained expertise in characterizing the evolution of bacterial antibiotic resistance during hospital-acquired infections as bacteria adapt to environmental stressors (including humidity, surface topography, and immune response). Now I am focusing on developing technologies targeting the control of biofilm and associated drug resistance using magnetic force-driven engineered Escherichia coliand dynamic surface topography. The E. coli cells were engineered to respond to magnetic force differently according to their level of metabolic activity or resistance. These magnetic force-driven novel technologies, when further advanced, will have broad applications for designing innovative medical and environmental antifouling strategies or for probing and drawing out medical or environmental contaminants. Please refer to my curriculum vitae (CV) for the additional details on my research experience and relevant publications.

Teaching Interests: My goals as a teacher are to create a student-centered learning environment and develop new teaching methods to promote active and self-directed learners who will not only master the principles of chemical engineering but also be able to employ their knowledge and skills independently to solve complex problems and gain greater fluency. In the future, I envision myself teaching in both classroom and laboratory, as well as mentoring students in my research lab. Each of these settings requires a unique type of engagement with students. To address these varying needs, I have developed different teaching methods that seek to advance students’ learning experience and achieve my goals as a teacher. With my training in Chemical Engineering, I am looking forward to teaching core courses in this discipline including Transport, Thermodynamics, Reaction Engineering, and Separation Processes. I am also interested in developing new courses related to nano- or micro- techniques for cell manipulation, microbes and human life, and methods for exploring cell microenvironments.

Future Directions: In my faculty position, I plan to strengthen and grow my work into a problem-driven multidisciplinary research program, with the goal of facilitating students to identify emerging problems and design new solutions from an interdisciplinary approach. Nowadays, nosocomial (hospital-acquired) infections, especially those caused by multidrug-resistant pathogens, are posing great threats to the immunocompromised individuals and public health in general due to their contributions to antibiotic resistance. Thus, the mission of my future research team will be to design more efficient antimicrobial surfaces and antibiotics for the control of nosocomial infections, based on the fundamental understanding of bacterial physiologic response to the physical and chemical stressors in both built and host environments. My previous research on the physiology and genetics of bacterial pathogens in the hospital and host environments has broadened our knowledge on how physical and chemical stressors influence the level of antibiotic tolerance. Building upon this foundation, my future translational research program will first target the design of novel molecules that will have a better accumulation in both sessile and planktonic pathogens by engineering their physiochemical property. To facilitate the development of new molecules specifically targeting the subpopulation of pathogens with high tolerance to antibiotics (also called persisters), I propose to engineer bacteria to ‘sense’ magnetic field. By spatially and temporally controlling gene expression using programmed magnetism regulation, I want to establish a platform that can achieve a cheaper, faster, and more robust isolation of cell groups with different levels of antibiotic tolerance for the high-throughput screening of molecules relevant to drug discovery. Finally, I aim to revolutionize the dynamic surface topography that I have established during my past research into next generation antifouling surfaces by employing magnetic force as an engine to drive the movement of polymeric surface topographies filled with iron nanoparticles. The magnetic field, with the combination of generated electric current and conductive material, can be used to design a remote technology for the detection and elimination of biofilms in both built and host environments.

I am confident that my doctoral and postdoctoral training has prepared me for establishing a successful independent research program that will make major contributions to the understanding and control of biofilms, especially, in the hospital environment. Given the interdisciplinary nature of biofilm research and close medical relevance, there are exciting opportunities to collaborate with other fields, such as biostatistics, computational modeling, microbiology, architecture science/engineering, ecology and evolution, and immunology to pursue large multidisciplinary grants. Results from these studies also have the potential to inform industry stakeholders in the development of innovative antifouling products. Beyond research studies, the biofilm-related problems are also suitable for integrating into engineering courses and for outreach with local K-12 students and teachers to promote STEM education and talent development.