{
  "abstract": "Background The massive increase in vaping worldwide is primarily due to the perceived safety of vapes as a nicotine alternative to cigarettes. However, the long-term health effects of vaping remain unknown. The E-cigarette or Vaping Use-Associated Lung Injury (EVALI) outbreak of 2019 showed the dangers of using vaping products without proper research into the chemicals contained in them. Aldehydes give vapes their unique flavours, and they all react with propylene glycol during vaporization to form acetals. Acetals are more hydrophobic than aldehydes, so will hypothetically compromise the first line of defense against inhaled hazardous substances (i.e. lung surfactant), via interaction with the lipid monolayer.Aim Characterize the effects of Ethyl Vanillin (EV) and Ethyl Vanillin Propylene Glycol Acetal (EVPGA) on the surface tension, compressibility and hysteresis of lung surfactant.Methods A constrained sessile drop surfactometer and drop-shape analysis were used to measure the surface tension of water drops that had been surface-lined with Dipalmitoylphosphatidylcholine (DPPC), a synthetic lipid-mixture of lung surfactant (SLS), or clinically used surfactants (Alveofact), during multiple compression-expansion cycles at physiological breathing rates. EV and EVPGA were then spread at the surfactant-lined drop’s air-liquid interface. The compression-expansion cycle was repeated, and the minimum surface tension was compared before and after the vaping chemicals were applied. Compressibility and hysteresis before and after adding the vaping chemicals were calculated and compared, using data collected from the compression-expansion cycles.Results EVPGA reduced the compressibility of DPPC by 54.12% (P=0.0354) and Alveofact by 37.71% (P=0.0116) in the first 5 cycles. EV raised the minimum surface tension of Alveofact by 55.67% during the first 5 cycles (P=0.0130) and 86.87% (P=0.0036) in the last five and decreased the compressibility by 45.84% (P<0.0001) in the last 5 cycles. EV and EVPGA had no significant changes on SLS or hysteresis.Conclusion In our study, EV and EVPGA significantly reduced the effectiveness of the lung surfactant by compromising its biophysical properties of surface tension and compressibility. This necessitates further research into many other different acetals and their flavouring parent aldehydes to gain a holistic understanding of the dangers of chronic vape use to prevent future deaths.",
  "authors": [
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "KLS Lutchman Singh"
    },
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "ZZ Zhou"
    },
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "JBS Bernardino de la Serna"
    }
  ],
  "title": "M1 How vaping chemicals compromise lung surfactant",
  "uid": "b906bd5f-a125-582e-a94c-25f948baa15c"
}