0508207 Wiesner Understanding the bio-reactivity of fullerenes, which are C60 nano materials, is important because of the many applications for which these nanomaterials are being considered. Fullerenes are known to have a high electron affinity and high reactivity with nucleophiles. They may serve as photosensitizers to produce reactive oxygen species such as hydroxyl radicals, superoxide radical anions, and peroxyl species, all of which are highly bio-reactive species. The potential biological effects of fullerenes that could result from these characteristics are not well understood. They may cause a wide variety of toxic effects to various organisms, but they also have the potential to be developed into engineering strategies to control biofouling or disinfect water. This project is studying the chemistry of reactive oxygen production by fullerene-based nanomaterials in the context of assessing the associated effects of fullerenes on bacteria and viruses. Specifically, the investigators are evaluating three hypotheses: (1) that fullerenes can act photocatalytically or through dark reactions to produce reactive oxygen species that inhibit or inactivate microbial growth; (2) that the reactive oxygen species formed from fullerenes hinder heterotrophic and photosynthetic activities and cause population shifts reflecting differential responses and protective mechanisms used by different species; and (3) that oxidative stress of cell membranes through peroxidation and epoxidation of phospholipids is an important mechanism responsible for cell death.
