This proposal deals with in vitro and in vivo fate studies of engineered nanomaterials (NMs). ZnO, Au and PLGA NPs and Graphene will be produced with controlled shape, size and surface properties. The intracellular localization, dynamics and state of aggregation of the NMs will be first studied in vitro by a combination of biophysical techniques. Ion Beam Microscopy will be applied to determine intracellular dose of ZnO and Au NPs. Toxicological studies will be performed and related to the intracelular dose. The stability of the bio corona and conformational state of proteins in the corona will be studied intracelularly. NMs will be further radiolabelled for in vivo imaging and strategies for dual radiolabelling will be developed. Positron Emission Tomography and Single Photon Emission Computed Tomography will be applied to study the biodistribution and fate of radiolabelled NMs in small rodents following different administration routes. By dual radio labelling the in vivo stability of NMs will be investigated.
The synthesis of various nanomaterials (NM) will be carried out, including metal and metal oxide nanoparticles, polymeric PLGA based nanoparticles, as well as graphene and graphene oxide nanomaterials. The materials will be surface-functionalized in different ways, and the introduction of dual radiolabels in the core and in the corona will be explored to be able to track the location of the NM during in vitro and in vivo studies by collaborators. Characterization of the NMs involves zeta potential measurements, DLS, NTA, ATR-FTIR, TEM, and micro scanning transmission ion microscopy. The specific interactions between the nanoparticles and their corona will also be explored by molecular simulation, which allows to track the effects of surface chemistry on ligand packing, binding strength, and agglomeration of the nanomaterials. Further tests by steered molecular dynamics simulation aim at understanding the translocation process through cell membranes and probing the stability of the nanoparticle corona. Specific interactions with selected peptides and proteins will be explored in models to rationalize accumulation in specific organs and tissues as experimental information becomes available. A combination of all-atom and coarse-grain simulations will be employed to explore length scales from nanometers to micrometers.
The knowledge generated in this project will be essential to understand the behavior of nanomaterials at cellular and organism levels with the ultimate goal to minimize toxicity. This objective is of paramount importance for future developments in cosmetics, medical and pharmaceutical products, as well as for new structural materials enhanced by nanoscale materials to which humans are exposed. The synthesis, modeling, and testing of various systems also helps uncover ways in which nanomaterials may be designed to minimize toxicity. Nanomaterial stability studies will also tackle issues such as the stability of the coating around the core, the stability of the core itself as well as the degree of aggregation of the nanomaterials. In the project we propose a complex and unprecedented combination of labelling strategies, which will allow the PI to address these issues through highly sensitive, non-invasive imaging techniques such as PET or SPECT. The stability of surface coating can explain why the same nanomaterial core can have different toxicity when functionalized with different coating or even when the same coating is linked to the nanomaterial surface in different ways. Coating and nanomaterial stability in relation with their distribution can explain specific toxicological responses as well as provide understanding on the time frame of the toxicological response. The nanomaterial stability can become a novel toxicological end point and be fundamental in risk assessment. Ultimately, the results will contribute to a quantitative evaluation of risks associated with the materials investigated. The proposed effort will also include the training of PhD students and outreach activities for High School students through Engineering Career Days and hands-on research experiences in university laboratories
