Molecular Remodeling Behavior Of Interactions Between Synthetic Nanomaterials And Alveolar Interface

With the development of modern industry,the application of nanomaterials in various fields,the release of nanomaterials into environment impact human health,but its toxicity mechanisms are still unclear.Inhaled nanoparticles(NPs)deposit in the alveoli,where they first interact with the pulmonary surfactant(PS)to cause dysfunction of the alveoli and change the physicochemical properties of NPs by forming corona,in further to influence their biological behaviour.In this project,we investigate molecular remodeling behavior of interactions between inhaled NPs and the alveoli by molecular dynamics simulation.The main research contents are summarized as follows:(1)Extracting PS molecules on suspended graphene nanosheets(GNs)PS molecules can spontaneously be extracted from the layer and form inverse micelles via cooperative move and redistribution on the GNs surface when GNs is suspended and slowly transmembrane.We demonstrated that PS layer tension,GNs size,GNs oxidation ratio and GNs curvature can significantly affect the extraction process.The PS absorbed on the surface of the nanosheets,changing the physicochemical properties of the GNs,and the adsorbent molecular structure can be considered to be the PS coroa that influence GNs biology properties.(2)The interactions between different shape NPs and PSThere are a variety of NPs,which have different shape,size and properities,the properties of their interfacial interaction with PS become different after inhalation into alveoli,the resulting NPs inhalation toxicity varies.We designed various sizes and shaps for hydrophilic and hydrophobic NPs to interact with PS.It was found that hydrophilic NPs with all dimensions smaller than 5 nm can rapidly penetrate through the PS layer,being barely affected by NP shape,while shape matters in both translocation and PS perturbation for larger NPs;the larger hydrophobic NPs could absorb PS and form corona.The hydrophobic NPs of the sharp shape causes the disturbance of the surrounding PS,which causes the rupture of the PS layer.Our results suggest that all studies of inhalation toxicity should consider shape significantly matters.(3)The atmosphere recombination of carbon nanotubes(CNTs)and polycyclic aromatic hydrocarbons(PAHs),and interaction between complex and PS.PAHs are typical components of organic volatiles and have been shown to cause high biotoxicity when inhaled.However,in complex atmospheric environments,nanomaterials(especially carbon nanomaterials)adsorb certain amount PAHs,which are inhaled into lungs in the form of nanocomposites,causing multiple complex toxicity.In this context,we designed a composite system of PAHs and CNTs,we studied the interaction between the complex and PS The research indicate that: CNTs can adsorb PAHs to form single or multi-layer structures;CNTs can stabilize the adsorption of PAHs on their surface and are not easily dissolved by PS,their adsorption strength is affected by PAHs adsorption sites.Our results indicate that the atmosphere recombination of CNTs and PAHs,and interaction between complex and PS should be considered in the study of inhalation toxicity of synthetic NPs.In this thesis,the interaction mechanism between nanomaterials with different size,shape,hydrophobicity,suspension and adsorption of PAHs in the atmosphere and PS was systematically studied,which provided a new understanding in explaining the mechanism of inhalation toxicity of nanomaterials.