Title : Interaction of gold nanoparticles with lung surfactant: A coarse-grained molecular dynamics study
The rapid development of nanotechnology increases the huge aspects of Nanoparticles (NPs) in biomedical applications particularly gold nanoparticles (AuNPs) with the potential health risk associated in instigation of lungs diseases. Being nanoscale size, the NPs easily enter our organism through lungs, where the NPs primarily interact with a thin barrier usually called lung surfactant (LS). The stability of lungs through normal breathing entirely controlled by the intrinsic LS functions, therefore it is crucial to understand the functions of the LS exposed to AuNPs at molecular level. The overall aim of the study is to explore the dual-role of AuNPs in lungs area and elucidate the nano-bio interactions molecularly. It is indispensable to study the model LS layer (first biological barrier inside lungs) at air-liquid interface exposed to AuNPs, so that the lung diseases caused by the NPs can be revealed with the role of NPs’ concentrations, sizes, shapes and surface properties. In this investigation, coarse-grained (CG) molecular dynamics simulations are performed to a series of LS monolayer models with AuNPs at the interface during breathing cycles. It is observed that the bare AuNPs and its’ concentration structurally deform the monolayer, change the biophysical properties of LS and create pores in the monolayer, which all interfere with the normal lung functions including surface tensions at the interface. It is also found that AuNPs significantly disrupt the monolayer packing during monolayer in inhalation state than exhalation state. In case of coated AuNPs in model LS, the surfactant monolayer associated hydrophobic peptide aggregates in the monolayer during the simulations. Overall, these findings could help to design nanomedicines to improve drug delivery capacity in lungs as well as in identifying the possible consequences of airborne NPs inhalation at molecular level.