Collaborative Research: Interactions of Airborne Engineered Nanoparticles with Lung Surfactant Films

Rapid developments in nanotechnology have led to the production and use of various types of engineered nanoparticles. It is inevitable that airborne nanoparticles may be released to the environment and may cause potential consequences for human health, in particular, in the respiratory tract including the lung (alveolar region) once inhaled. The lung surfactant, which covers the alveoli as a thin liquid film, represents the first line of defense against such airborne nanoparticles at the air-liquid interface. This collaborative project, involving a synergistic combination of experimental and computational studies, seeks to study the effects of physicochemical and structural properties of engineered nanoparticles on interfacial flow behaviors and stability of surfactant films. This research activity also is aimed at obtaining a better fundamental understanding of the molecular interactions arising between surfactant films and potentially hazardous engineered nanoparticles in realistically imitated physiological conditions. Fundamental knowledge gained through this project is, therefore, expected to provide new insights into the subsequent retention, translocation, and clearance of inhaled nanoparticles and the sequential processes associated with engineered nanoparticle toxicity overall. The project results will also advance the basic knowledge of the fate of biological nanoparticles, such as coronavirus virions, in the lungs that may have practical implications in medicine. Educational and mentoring aspects of this project include training graduate students in advanced surface science tools and computational techniques, mentoring underrepresented undergraduate students in research, and developing teaching modules and subjects relevant to nanoparticle interactions in biological systems.

As the production and use of engineered nanoparticles increases day by day, it is inevitable that these nanoparticles will be released to the environment. Therefore, the occurrence and fate of engineered nanoparticles in the environment, and the potential consequences on human health have been increasingly recognized as issues of critical importance. In particular, airborne nanoparticles can result in a much greater likelihood and extent of exposure to the environment and thus living beings. This collaborative project will focus on improving our fundamental understanding of the molecular interactions between engineered nanoparticles and lung surfactant films at multiple-length scales. The project will evaluate the distribution and fate of inhaled airborne nanoparticles in the respiratory tract. This research project is structured around two specific objectives. First, this project aims to determine the effects of physicochemical and structural properties of inhaled engineered nanoparticles on the viscoelastic responses and interfacial stability of lung surfactant films. Second, the project will generate fundamental data concerning the molecular mechanisms of interfacial interactions in lung surfactant monolayers and multilayers in the absence and presence of engineered nanoparticles at multiple length scales in physiological environments. To achieve these goals, a synergistic combination between experimental and computational approaches will be employed. Experimental advances include a specially modified Langmuir trough, a quartz crystal microbalance with dissipation coupled with a custom-made particle generator unit, and a highly sophisticated surface forces apparatus. The computational component is based on a new coarse-grained computational framework for investigations of nanoscale interfacial processes at air-liquid interfaces, including dissipative particle dynamics models to predict the composition dependent surface tension, elasticity, viscosity, and stability of lung surfactant monolayer and bilayers with doped engineered nanoparticles. These collaborative experimental and computational studies of nanoscale interfacial phenomena are expected to provide qualitative and quantitative information on the viscoelastic properties of lung surfactant films and the attendant response to shear stresses upon breathing affected by adhered/piercing engineered nanoparticles. In addition, the principal investigators will generate systematic information on molecular interactions of engineered nanoparticles with the lung surfactant system, especially in terms of adhesion and fusion behaviors that are related to the structural integrity of lung surfactant films. The findings gained through this project will improve mechanistic understanding of the adhesion and translocation of nanoparticulate matter (e.g., coronavirus virions) across other general cell membranes. Educational components of this project involve training graduate students and mentoring undergraduate students from underrepresented groups in engineering through various programs offered at Rutgers University and the University of California, Riverside.

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.