Human exposures to industrially relevant engineered nanomaterials (ENMs) are increasing in occupational and environmental settings. Inhalation is a major route of entry. Airborne nanoparticles (NPs) reach the deep alveolar region of the lung where they encounter biomolecules of the alveolar lining fluid. The interaction results in the formation of a phospholipid-protein corona on the NP surface. The very first step in this encounter is underappreciated and poorly characterized, but is critical in determining subsequent fate and effects of NPs. The investigators preliminary data show that NPs of different chemical composition develop a characteristic phospholipid-protein corona while interacting with biomolecules of lung lining fluid. They also found the pulmonary responses and lung clearance profiles for these diverse NPs to be dramatically different. With the rapidly expanding field of nanotechnology, hundreds of novel NPs exhibiting diverse physicochemical properties are being generated. It would be practically impossible and prohibitively expensive to evaluate toxicity of all of them individually as every change in NP chemistry, charge, size, or shape constitutes a potentially new material requiring toxicological study. Therefore, there is an urgent unmet need for developing high-throughput screening assays for predicting pulmonary clearance and toxicity of NPs. This comprehensive study will identify and connect phospholipid-protein corona profiles to particokinetic and toxicological endpoints. The investigators propose to examine the independent and collective effects of the six major proteins and six phospholipids of lung lining fluid on the uptake of NPs by cells such as macrophages and their subsequent responses. They will also evaluate the role of the phospholipid-protein corona in modulating translocation of NPs across the air blood barrier. Additionally, the investigators propose molecular dynamic simulation studies for understanding the nature of NP-biomolecular interactions in alveoli. They will test the effects of varying physicochemical properties such as size, shape and surface functionalization on the corona composition. They will create a phospholipid-protein corona profile database library that integrates corona analyses with molecular dynamic simulation data. While the project builds on extant work in the field, it is unique (a search of NIH Reporter and PubMed does not reveal any similar efforts that use comprehensive corona profiling to predict nanotoxicity) and addresses an important need. This transformative study takes advantage of phospholipid-protein corona profiling to create a high-throughput predictive nanotoxicity model that identifies critical factors controlling NP toxicity. The proposed research will enable systematic risk assessment and classification of nanomaterials based on their corona profiles in addition to other parameters used to group nanomaterials such as their size, physicochemical features, biopersistence and acute toxicity. Further, the study will enable in prevention of the adverse effects of nanomaterials and their use in nanotechnology.
Understanding the composition of the phospholipid-protein corona and its predictive power in regard to nanoparticle-mediated cellular responses and translocation of nanoparticles across the air-blood barrier is the major tenet of this application.