Interactions of Carbon Nanotubes and Carbon Nanohorns with a Model Membrane Layer and Lung Surfactant In Vitro

Abstract

A broader use of carbon nanomaterials increases the risk of their inhalation as aerosol dispersed in the air. Inhaled nanometer-sized particles are known to penetrate to the pulmonary region where they interact with the lung surfactant as the first barrier they meet and eventually penetrate to the surface of the cellular layer. This study presents the results of experimental studies of physicochemical interactions between several types of carbon nanomaterials (nanotubes and nanohorns of various size and surface properties) and lipid layers in two qualitatively different experimental systems: Langmuir trough and pulsated drop tensiometer, both providing complementary possibilities to study interfacial properties of the lipid-rich layer. Quantified alterations in mechanical properties if lipid films (equilibrium compressibility, dynamic surface elasticity, and viscosity) indicate that nanocarbons with different wettability may induce concentration-dependent frustration of the lung surfactant and biological membranes in vivo. The observed effects are discussed not only in relation to health effects from nanoparticle inhalation but also to potential medical applications of engineered carbon nanomaterials.