Behavior Of Carbon Nanomaterials And Polycyclic Aromatic Hydrocarbons On Pulmonary Surfactant Membrane

Carbon nanomaterials(CNs)is an important component of air pollutants,and also an important carrier of toxic and harmful components such as polycyclic aromatic hydrocarbons(PAHs).Because of its adverse environmental and health effects,it has been a global focus on environmental issues.The inhaled fine particles will first interact with the pulmonary surfactant(PS)in the alveoli Because of the special interface chemical characteristics of PS(such as reducing the surface tension and solubilization),the contact of PS can have an important impact on the aggregation form of particles,the apparent dissolution of pollutants,the transmembrane ability of pollutants,and then affect the bioavailability of pollutants,which has a serious impact on lung health.In this paper,the porcine PS(which was found to be very similar to the structure and function of PS in human lung)was used as the model of PS,and the typical CNs and PAHs were selected as the representative of the air composite pollutants to study the stability of CNs on the PS membrane,and their stability changes and settling capacity were investigated.The dynamic light scattering instrument was used to analyze particle size distribution.The microstructure of PS membrane in the presence of particles was observed by Brewster angle microscope to prove the change of particle stability.Zeta potential and surface functional groups were analyzed to explore the mechanism of action.Graphene oxide was selected as the representative of CNs in the atmosphere,and the adsorption of graphene oxide on PAHs and the active components of PS was studied.The influence of PS and its active components on the adsorption behavior of PAHs on graphene oxide was also investigated.The solubilization of PS and its active components on PAHs was studied,and the effect of agglomeration on PAHs was investigated This is in line with the role of the pollution system,and the reason of agglomeration is analyzed by FTIR.In order to simulate the permeability of PAHs,the porcine surfactant was used as membrane material and the appropriate concentration was selected.The apparent permeability,effective permeability and residual coefficient were used as bioavailability indexes to investigate the physicochemical properties that affect the permeability.The specific research results are as follows:(1)Compared with normal saline,PS reduced the suspended concentration of three CNs.With the addition of DPPC,the main component of PS,the suspensionconcentration of CNs decreased and the particle size increased,while the presence of BSA promoted the dispersion of the three CNs,the particle size decreased and the suspension concentration increased.Compared with PS or DPPC,BSA significantly increased the absolute surface potential of CNs,and was related to the surface oxygen content of carbon nanoparticles and PS or its components.(2)PS and its components have solubilization effect on PAHs,graphene oxide has certain adsorption effect on PAHs and PS,and there is competitive adsorption between PAHs and PS.after entering the lung,PS and its components occupy the adsorption site of PAHs and load on the surface of graphene oxide;PAHs desorb on the surface of graphene oxide under solubilization effect of PS and its components,with enhanced toxicity.At the same time,PAHs and PS can promote the aggregation of graphene oxide,and the particle size increases more than three times;the increase of C=C bond and the force of chemical bond conversion affect the stability of graphene oxide.(3)A parallel artificial membrane permeability assay(PAMPA)was established to evaluate the permeability of PAHs on PS membrane.The apparent permeability,effective permeability and residual coefficient of PAHs were used as bioavailability indexes.The results show that the n-octanol-water partition coefficient can not directly predict the permeability,and there is no significant relationship between permeability and polarity.Dispersion,induction and coupling/polarization promote permeation,hydrogen bond has a strong inhibition on permeation,while n-n electron interaction has a small inhibition on permeation.This work provides a theoretical basis for the lung risk assessment of inhaled particles and PAHs,and is of great significance for the assessment of the stability,bioavailability and human health risk of PAHs and particles entering the lung.A new parallel artificial osmotic membrane is established to rapidly assess the permeability of PAHs passive cross pulmonary surfactant membrane,so as to further understand PAHs The bioavailability of hydrocarbons provides a prediction method.