The scientific community has recently determined that the physical and physicochemical properties of nanoparticles (NPs) deemed so desirable in terms of application are often the direct causes for their complex behavior in the environment. Upon entering the environment through air, water and soil, and during the lifecycle of manufacturing, transport, use and disposal, NPs "at large" undergo constant transformations from their interactions with light, natural organic matter (NOM), microorganisms, and plants. The goal of this proposal is therefore to elucidate the mutable behavior and fate of discharged NPs by extrapolating the established concept of protein "corona", i.e., surface modification of NPs by plasma proteins in the bloodstream, to "biocorona" in the environment. The notion of biocorona encompasses NOM, proteins and carbohydrates that are ubiquitous building blocks of nature. This proposed treatment is validated in that a) biological systems are an essential and integral part of ecosystems, and b) it is the transformed rather than the pristine material, that must be evaluated for potential environmental impact.
Intellectual Merit: Technically, the introduction of biocorona exploits the established experimental, theoretical and computational approaches developed for the research areas of protein adsorption and folding while integrating the elements pertaining to nanotechnology and environmental systems. The three specific aims of this proposal are to elucidate a) NP-biocoronas in the natural aqueous environment, b) NP-biocoronas in plants, and c) biotransformation and degradation of NP-biocoronas by aquatic organisms. The parameter space to be mapped includes solvent hardness and pH, NP size and solubility, protein conformation and binding thermodynamics, plant cell translocation, transport and phytotoxicity, ROS production, and photosynthesis. Results from these studies will offer essential information on the stability and transformation of NPs in the natural aqueous environment, facilitate our understanding of the uptake, biodistribution and toxicity of NPs in plant species, and provide key indicators for evaluating aquatic response to NP exposure.
Broader Impacts: Recent literature on the environmental health and safety of nanotechnology (NanoEHS) has expanded exponentially. Much NanoEHS study is now converging from phenomenological observation and mass testing toward amassing a knowledge base of increasing efficiency and prediction power. To keep pace with the vast variety and growing application of nanomaterials and to accommodate the vast complexity of the environment, methodical approaches such as extrapolated concept of biocorona are logical and cost-effective solutions to environmental risk assessment of nanotechnology. In addition to promoting interdisciplinary research and education at Clemson and Wake Forest University in the Carolinas, funding of this proposal will catalyze fusion of the protein folding community with the community of NanoEHS for cutting-edge innovation with potential economical gains. Furthermore, this proposed frontier research will necessarily foster exchanges between the PIs' labs and their collaborators at Delaware State, Denison, Duke, and Rice Universities, and the National Institute of Chemical Physics and Biophysics in Estonia.
