Projects

Nano-scale Plastic Aquatic Toxicology

Aquatic ecosystems are polluted with plastic waste on a global scale. As plastics degrade in the environment, they inevitably pass through the size range in which they would be considered microplastics (< 5mm) and nanoplastics (1-1000 nm). The goal of this research is to provide foundational information about what physicochemical properties (e.g., composition, size, shape) and environmental components (e.g. salinity, pH, organic matter) are determinative of risk. This project entails 1) a thorough characterization of the physicochemical composition, size, and shape of common plastics that have been milled to the micro- and nano-scale, 2) studies to determine the biological consequences of micro- and nanoplastics exposure in freshwater and estuarine model organisms using rapid toxicity testing strategies, and 3) studies todetermine how real world transformations of micro- and nanoplastics may alter plastics fate or the fate of plastic additives and co-contaminants. All of the data from these studies will be used to inform a multi-stressor risk assessment model.

Zebrafish EZ Metric Assay

Since virtually every element on the periodic table is fair game for exploration in nanotechnology, the sheer diversity of nanomaterials makes it impractical to utilize our current testing paradigms to evaluate every new nanomaterial.  We use the embryonic zebrafish as an in vivo model to easily and rapidly advance our understanding of the biological consequences of nanomaterial exposure. This model system offers the power of whole-animal investigations (e.g. intact organism, functional homeostatic feedback mechanisms and intercellular signaling) in a convenient cost- and time-efficient manner.

Nano-Crystalline Cellulose (NCC)

The overall objective of the NCC project is to determine the relative influence that size, shape and surface chemistry of nanoparticles has on their uptake and biological effects  as well as to understand the mechanism of toxicity. NCC is an innovative platform for testing data-derived nanoparticle structure-activity relationships (nanoSARs). NCC is thought to be predominantly non-toxic, thus key features that confer toxicity to some nanomaterials can be elucidated though deliberate permutations of the physical structure of NCC. With over 100 years of cellulosic chemistry to rely on, engineers in wood science engineering here at OSU have partnered with our lab to establish new methods of NCC synthesis and characterization to formally test the validity and limitations of data-derived nanoSARs.

Nanocosm Assay

Rapid testing strategies are necessary to identify the specific features of nanomaterial that result in toxicity in order to mitigate risks from exposure and define structure-property relationships that can be used to predict nanomaterial fate and hazard in lieu of empirical data.  Mesocosms and microcosms are now widely accepted as useful tools for investigating the ecotoxicity of a substance since they take into account relevant aspects from a simulated ecosystem such as bioavailability, indirect effects, biological compensation and recovery, as well as community level effects and the potential for trophic transfer and biomagnification.  Traditional micro/mesocosm studies are time-intensive and require a large amount of material for testing. Our goal is to overcome these critical limitations in ‘nanocosms’ whioch are small-scale simulated ecosystems with reliable reference conditions and sufficient cost-effective replicates.

Oxidative Potential Assay

This project aims to develop a rapid and cost effective testing strategy to examine nanoparticles for their oxidative potential. Reactive Oxygen Species (ROS) are often the root of chemical reaction cascades that lead to free radicals and oxidative stress. Some nano-scale particles show strong chemical reactivity and can act as reaction catalysts. In biological systems, these same properties can also lead to a destructive process called oxidative stress. Oxidative stress is biological damage caused by highly reactive molecules like free radicals. Oxidative stress plays a part in many diseases such as: atherosclerosis, Alzheimer’s disease, cancer, Parkinson’s disease, stroke, and even aging. The information from this assay will further be used to interpret the physiochemical properties of nanomaterials that are responsible for causing oxidative stress in biological systems.

Hyperspectral Imaging

Our lab uses a Cytoviva Hyperspectral Imaging System to detect nanomaterials and agglomerates in biological samples. The system creates an image of the sample containing spectral information through the visible range, which is then compared to the reference spectra of a known sample in order to determine if nanoparticles are present in the target sample. The HIS system can be used to qualitatively assess the distribution of nanomaterials in complex biological matrixes such as animal tissues or algae.

NanoScanner Design and Development

Our lab is currently working on the prototype of a novel charactarization tool for nanoparticles. The NanoScanner analyzes nanoparticles based on how they interact with simulated biological systems and chemical environments. This is a high-throughput benchtop system that utilizes microchannel arrays and microcapillary tubes. The Nanoscanner is being designed such that a a sample of nanoparticles can be injected into a water-based carrier stream feeding a microchannel array, where an electric field gradient is imposed to separate the particles based on hydrodynamic radius. Next the nanoparticles enter the isoelectric separation plate, where they are separated based on charge. Lastly, they flow through microcapillary tubes, where the interaction with simulated biological systems is determined. Each tube has three different regions: lipophilic moieties, hydrophylic moieties and receptor specific moieties. Engineering students in the lab are currently working on identifying and optimizing separation media, identifying stable surface chemistry for microchannels and developing process controls.

Nanomaterial-Biological Interactions Knowledgebase

The Nanomaterial-Biological Interactions knowledgebase (NBI) is a collaborative web-based database designed to integrate relevant data from ongoing academic, government, and industrial research on nanotechnology. The NBI serves as an open-source repository for data on nanomaterial characteristics and their biological interactions. Users can access unbiased information from the database to help identify the relative importance of characterization parameters on nanomaterial-biological interactions.To access the database go to nbi.oregonstate.edu.

Nano Environmental Health and Safety (EHS) Certification

Our lab is working with ASTM International on the development of a nanotechnology environmental health and safety certification program to provide EHS managers, from expert to novice, a fundamental understanding of the core principles of toxicology and nanotechnology. Components of the certification program include the evolution of policy and regulations, societal impacts, the role of non-government organizations, risk assessments for nanomaterials, risk management practices and to promote green Nanoscience.

Effects of Pesticide Nanotechnology on Vulnerable Organisms

Nanotechnology-based pesticides are based on existing active ingredients, and possess internal functional features less than 100 nm that are purposely engineered to have different properties in the environment than the active ingredient. Nanoformulation of pesticides may not increase the toxicity of the active ingredient per se, but are likely to alter their environmental fate. The overarching goal of the project is to reduce the uncertainty associated with NBP formulations in terrestrial and aquatic environments and communities through simultaneous studies of NBP toxicity in honey bees, zebrafish and other aquatic organisms.