CAREER: Transport and transport effects of magnetic nanoparticles in bacterial biofilms

About This Grant

Biofilms are collections of bacteria that adhere to surfaces. They pose serious challenges in manufacturing, food safety, and medical practice. This CAREER project will explore how magnetic nanoparticles could weaken biofilms and prevent their growth. The team will use magnetic fields to push magnetic nanoparticles into a biofilm, make the nanoparticles rotate, or make them heat up inside the biofilm. The team will analyze how each of these actions affect the biofilm’s health by measuring how many bacteria survive the nanoparticle treatment. Anticipating that properties of the biofilm may affect results, the team will conduct experiments for a set of biofilms that vary in viscosity and chemical composition. The results will help clarify how forces and heat generated by the magnetic nanoparticles weaken biofilms. The methods explored in this project could prove useful to treat infectious diseases, to prevent foodborne outbreaks, or to minimize damage in pipes. The results will also help identify antimicrobial mechanisms of other nanoparticles. The team will integrate a hands-on training pipeline to introduce students to the challenges that biofilms pose across industries. This CAREER project will help understand the nanoscale interactions between magnetic nanoparticles and bacterial biofilms. The research team will experimentally study the effects of magnetic nanoparticles on biofilms under different regimes of magnetic actuation: static magnetic field gradients leading to magnetic nanoparticle penetration through the biofilm, low frequency rotating magnetic fields leading to localized shear forces acting within the biofilm matrix, and high frequency alternating magnetic fields leading to localized heating, a process known as magnetic hyperthermia. Each of these magnetic actuation regimes presents a different mode of action that must be understood. To understand these modes of action, the research team will analyze a diverse set of biofilms for their composition and physicochemical properties and relate these properties to bacterial viability and biofilm morphology after treatment. The team will elucidate what biofilm physical properties affect the magnetic nanoparticle biocidal action, and what aspects of magnetic nanoparticle treatment must be tuned to biofilm properties to achieve maximal biofilm removal. An experiential training pipeline to introduce engineers to the challenges of biofilms across industries will be developed, through the integration of education activities for students from high school to graduate level. Overall, this project addresses a knowledge and education gap in engineering novel antimicrobials. Biofilms are ubiquitous on Earth and cause problems across diverse industries due to their resistance to physical or chemical challenges. The magnetic nanoparticle-enabled antimicrobial methods can be translated to treatments against antibiotic-resistant bacteria in healthcare, to prevent spoilage in the food industry, or to avoid fouling in difficult-to-reach pipelines. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.