The large-scale use of plastics has resulted in an accumulation of plastic waste in marine ecosystems, where weathering processes can result in the formation of plastic particles that are small enough to enter the food chain. These small plastic particles are commonly referred to as microplastics or nanoplastics, depending on their exact size. Plastic particles can act as carriers of certain carcinogens, bringing potential risk to the food chain and ultimately to humans. However, the interactions between carcinogens and plastic nanoparticles remain insufficiently understood. This project will address key questions related to the nanoplastics-mediated uptake of carcinogens. The absorption and release of carcinogens from nanoplastics will be investigated in an intestinal model. In synergy with the laboratory work, this project will provide training opportunities in nanotechnology and nanotoxicology. Furthermore, educational web modules on nanoplastics will be developed geared towards a general audience with diverse educational backgrounds.
Polycyclic aromatic hydrocarbons are carcinogens that are generated through incomplete combustion processes of organic materials. Human activity has become a major source for polycyclic aromatic hydrocarbons and has resulted in a ubiquitous distribution of these molecules in the environment, including marine ecosystems. Polycyclic aromatic hydrocarbons have a high affinity for plastic nanoparticles due to their hydrophobic character. As plastic nanoparticles, are also accumulated in marine ecosystems, they represent a potential carrier for these carcinogens, which have a poor solubility in water. The sorption and release of polycyclic aromatic hydrocarbons to/from plastic particles depends on a variety of factors, including the chemical nature of the plastics, the size and morphology of the particles, and the pH and chemical composition of the surrounding media. This project will systematically characterize the effect of nanoplastics composition and weathering on the release of polycyclic aromatic hydrocarbons. The experiments will be performed with nanoparticles of different plastics with typical dimensions of 100 nm under well-defined conditions in a simulated gastrointestinal tract model, based on human colon carcinoma cells. Subsequently, the transepithelial transport obtained for free and nanoplastics-associated polycyclic aromatic hydrocarbons will be measured, and the effect of nanoplastics on the intestinal membrane integrity will be determined. By correlating membrane integrity with transmembrane polycyclic aromatic hydrocarbons transport, it will be possible to quantify the effect of nanoparticle-induced membrane damage on polycyclic aromatic hydrocarbons transport. Surface Enhanced Raman Spectroscopy will be applied to detect nanoplastics-induced molecular changes in the cell metabolism that do not lead to an acute change in membrane integrity but can still cause chronic damage. In synergy with the laboratory work, this project will enable substantial educational and training activities. The project will provide training opportunities in nanotechnology and nanotoxicology for at least one PhD student. Furthermore, micro- and nanoplastics have attracted significant public attention, and there is substantial interest in nanoplastics and their interactions with living systems, including humans. This project will develop educational web modules that collate existing information about this theme and disseminate the findings of this research project. These web modules will be geared towards a general audience with diverse educational backgrounds.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
