This NSF award by the Environmental Health and Safety of Nanotechnology program supports work by Professors Robert Hurt and Agnes Kane to characterize the biological interactions of graphene-based nanomaterials. Most research in nanomaterial safety focuses on a select group of high-volume materials for which significant human and environmental exposures are possible. Recently a new nanomaterial must be added to this list: graphene, the single-atom-thick sheet of graphite, which has attracted intense scientific and commercial interest since its discovery in 2004. Graphene and related materials with small numbers of layers (few-layer graphene) and chemical modified surfaces (graphene oxide), are now being manufactured at increasing volumes to meet research and development needs for a wide range of applications in electronics, structural materials, chemical sensors, inks and papers.
In this project a multidisciplinary team of engineers and toxicologists will investigate the interactions of graphene-family nanomaterials with biological molecules and with cells. A panel of commercial and developmental graphene-family materials has been assembled with variations in layer number (1 ? 30), lateral dimension (500 nm ? 25 um), and surface chemistry (pristine vs. graphene oxide) and will be thoroughly characterized for their relevant material properties as a first task. A second task will use high-throughput media profiling techniques to determine if graphene-family nanomaterials with very high surface areas will deplete vitamins and amino acids, or will interfere with dye-based measurement techniques used in toxicity testing. In a third task, the panel of graphene-family materials will be incubated with macrophages, a type of immune system cell that forms the first line of defense against microorganisms and foreign particulates inhaled into the lungs. These experiments will provide information on cell uptake, cell structure, oxidant production, cell viability, and production of inflammatory signaling agents as a function of mass does and surface area dose and using well-established, commercial, non-graphene, carbons as reference materials.
Broader Impacts -- This project will aid in risk assessment for graphene materials by providing data at doses relevant to occupational exposures. The results will also provide an early screening of the potential of these materials to pose risks to diverse biological systems, both human and environmental. Comparisons across the graphene material family suggest rationale grouping of graphene-based nanomaterials into regulatory or risk categories and can suggest safe design strategies. Additional broader impacts will arise through the investigators? continued commitment to public engagement on the regulatory and societal issues surrounding nanosafety. Broader impacts on human resources for U.S. science will be made through the support of young female and Hispanic researchers in the project and the investigators? participation in summer enrichment programs with Rhode Island high-school science teachers.