Nano-Environmental Studies of Biofilms

Nanotechnology is a rapidly growing technology. However, the release of nanoparticles into natural systems, is now recognized as an emerging environmental and health concern. Nanoparticles are extremely small (1-100 nanometers), even when compared to bacteria (approx. 1000 nm). Since nanoparticles can be engineered in highly-specific manners, their physic /chemical properties are often unique, when compared with those of dissolved molecules or small particlulates. Thus, the dispersion of nanoparticles through natural environments, and their bioavailability and biotransformation, remains largely uncertain. Bacterial biofilms, however, are now recognized as a natural ‘sorptive sponge’ for the binding and concentration of nanoparticles from surrounding waters. Therefore, the biofilm serves as an important ‘environmental window’ for understanding movements, transformations, and effects of nanoparticles released into natural systems. For example, efficient capture of nanoparticles by biofilms will influence their subsequent incorporation into food webs (and ultimately to humans).

The goals of our initial studies, funded by the National Science Foundation, are to examine specific: (1) biofilm/nanoparticle interactions under controlled laboratory conditions, and under natural conditions; and (2) in collaboration with the laboratory of Dr. Brian Benicewicz (USC), to determine if nanoparticles be used to: deliver antibiotics more-efficiently to biofilm bacteria, and to manipulate the process of chemical communication (e.g. quorum sensing) between bacteria within biofilms. This project involves the chemical synthesis of nanoparticles have highly-specific physical/chemical attributes. We are specifically examining how specific surface functional groups on nanoparticles influence their sorption and movement into biofilms, and influence the overall stability of biofilms.

Figure 1. Nanoparticles, being extremely small, travel readily through water systems. The sticky ‘EPS’ matrix of the biofilm is an efficient ‘sorptive sponge’ for chelation of nanoparticles. Functional groups on the nanoparticle surface likely influence binding to the biofilm.