E-cigarette aerosol exposure of pulmonary surfactant impairs its surface tension reducing function

Abstract

Introduction E-cigarette (EC) and vaping use continue to remain popular amongst teenage and young adult populations, despite several reports of vaping associated lung injury. One of the first compounds that EC aerosols comes into contact within the lungs during a deep inhalation is pulmonary surfactant. Impairment of surfactant’s critical surface tension reducing activity can contribute to lung dysfunction. Currently, information on how EC aerosols impacts pulmonary surfactant remains limited. We hypothesized that exposure to EC aerosol impairs the surface tension reducing ability of surfactant. Methods Bovine Lipid Extract Surfactant (BLES) was used as a model surfactant in a direct exposure syringe system. BLES (2ml) was placed in a syringe (30ml) attached to an EC. The generated aerosol was drawn into the syringe and then expelled, repeated 30 times. Biophysical analysis after exposure was completed using a constrained drop surfactometer (CDS). Results Minimum surface tensions increased significantly after exposure to the EC aerosol across 20 compression/expansion cycles. Mixing of non-aerosolized e-liquid did not result in significant changes. Variation in device used, addition of nicotine, or temperature of the aerosol had no additional effect. Two e-liquid flavours, menthol and red wedding, had further detrimental effects, resulting in significantly higher surface tension than the vehicle exposed BLES. Menthol exposed BLES has the highest minimum surface tensions across all 20 compression/expansion cycles. Alteration of surfactant properties through interaction with the produced aerosol was observed with a basic e-liquid vehicle, however additional compounds produced by added flavourings appeared to be able to increase inhibition. Conclusion EC aerosols alter surfactant function through increases in minimum surface tension. This impairment may contribute to lung dysfunction and susceptibility to further injury.

E-cigarettes and asthma in adolescents

“…This study is notable for these effects within 5–7 days of e-cigarettes use initiation with e-cigarettes devices that did not contain nicotine or flavourings. Another recent study suggested that flavourings led to reduced alveolar surface tension [41]. Cahill et al .…”

“…This study is notable for these effects within 5-7 days of e-cigarettes use initiation with e-cigarettes devices that did not contain nicotine or flavourings. Another recent study suggested that flavourings led to reduced alveolar surface tension [41]. Cahill et al [42] described the effects of in-utero exposures to mint flavoured JUUL aerosol and found increased inflammation in allergic asthma induced progeny, with increased pro-inflammatory cytokines interleukin-5, 10 and 13 in the pups of exposed mothers.…”

Pulmonary Surfactant: A Mighty Thin Film

“…Most importantly, the CL-ADSA enables droplet oscillation to follow well-defined sinusoidal waveforms, thereby allowing for the study of interfacial dilational rheology, which provides novel implications about the viscoelastic properties and chemical composition of the interfacial monolayer . The CDS has evolved into a versatile experimental platform capable of various surfactant and lipid related studies, such as interfacial rheology, , surface thermodynamics,, ,, lipid–protein interactions, , toxicology of nanomaterials, ,− health impact of e-cigarette aerosols, , synthesis of biomaterials, and biophysical studies of tear films − and xylem surfactants. , …”

Investigating the Effect of Medium Chain Triglycerides on the Elasticity of Pulmonary Surfactant

“…The introduction of foreign molecules into the active PS film can be detrimental to the respiration process by increasing the amount of work needed to breath . Interactions between toxins and PS have been investigated in understanding the onset of e-cigarette/vaping use-associated lung injury (EVALI). − The growing popularity of inhaled aerosol devices in the market has led to an outbreak of EVALI, with the Centers for Disease Control and Prevention (CDC) reporting 2602 cases and 57 deaths within the United States as of the beginning of 2020 . When surveyed, most of the affected reported use of tetrahydrocannabinol (THC) containing products, which were either THC-only containing products or mixtures of THC and nicotine. , The lack of sufficient quality control and large variety of e-liquid formulations makes it difficult in understanding from where this EVALI outbreak originates.…”