Systematic Analysis of Composition, Interfacial Performance and Effects of Pulmonary Surfactant Preparations on Cellular Uptake and Cytotoxicity of Aerosolized Nanomaterials.

The interplay of particles with pulmonary surfactant, a lipid-protein material pivotal for lung function, is hypothesized as a key factor that has not been routinely considered in the current in vitro models when determining the fate of inhaled nanomaterials. To explain its influence on cellular uptake and protective effects, nanoparticles are studied on two models of alveolar cells, in the absence or presence of pulmonary surfactant. Composition and interfacial performance of native human and porcine surfactants, a commercially available bovine surfactant (Alveofact), and an artificial lung lining fluid are characterized using shotgun lipidomics and biophysical approaches (i.e., Langmuir surface balances and captive bubble surfactometry). Plain and aminofunctionalized silica nanoparticles and a novel antimycobacterial nanoformulated benzothiazinone (BTZ043) are selected as examples of neutral, positively charged and therapeutically relevant nanoparticles, respectively. They are deposited onto monocultures of human alveolar epithelial and phagocytic cell lines in the presence or absence of the surfactant preparations, modeling the alveolar milieu. Only surfactant preparations with high interfacial activity and distinctive composition mitigated the toxicity of aerosolized particles, along with a tendency of aerosolized particles to aggregate. Key requirements of surfactant preparations needed when studying interactions of nanomaterials with the pulmonary air-blood barrier in vitro are identified.