电子烟是电池供电的设备，可通过加热“电子液体”来提供尼古丁。电子烟的使用（通常称为Vaping）已广受欢迎，尤其是在年轻一代中，随着有关传统香烟的不利健康影响的更多信息，更多的信息。现在，吸烟者正在转向电子烟作为更安全的选择。然而，尽管进行了越来越多的研究，但电子烟蒸气的潜在健康影响在很大程度上尚不清楚。

The potential health effects of e-cigarette vapor are largely unknown.

Due to their small size, the particles in e-cigarette vapor can reach deep into the lungs and a number of studies have focused on how e-cigarettes affect the cells of the pulmonary airways or the deep lungs. The majority of such studies have reported that e-cigarette vapor is less toxic compared to cigarette smoke; however, toxicity from e-cigarette vapor has been reported, depending on the dose and the flavoring of the e-liquid. While the studies on the effects of e-cigarette vapor on cell viability are undoubtedly important, an important aspect of e-cigarette toxicity, its potential effects on lung surfactant, has received far less attention.

A New Type of Study

肺表面活性剂是脂质和蛋白质的混合物，该蛋白质是肺肺泡区域。该表面活性剂层的主要功能是减少肺泡液的表面张力，从而减少呼吸的工作并防止肺泡塌陷。表面活性剂对于肺功能至关重要。没有表面活性剂出生的早产儿就患有婴儿呼吸窘迫，需要用外源表面活性剂治疗。肺表面活性剂与所有吸入颗粒（包括来自电子烟蒸气的颗粒）接触。我们的研究旨在了解电子烟蒸气是否影响表面活性剂减少表面张力的能力。

This study used calf lung surfactant extract (Infasurf^®, ONY Inc.), clinically used for the treatment of preterm infants, as the surfactant model. Infasurf^®was placed in a Langmuir-Wilhelmy setup, which allows for compressing the surfactant, mimicking lung mechanics, while measuring its surface tension. This setup was used to measure changes in surfactant after exposure to air, e-cigarette with three different e-liquid flavors (tobacco, berry, and mint), and conventional cigarettes. The use of different e-cigarette flavors was important as changing the e-liquid flavoring has been shown to change the chemicals in e-cigarette vapor.

E-Cigarette Vapor and Critical Lung Function

Results of the study found that e-cigarette vapor, regardless of its flavoring, does not affect the ability of surfactant to reduce surface tension. In contrast, conventional cigarettes significantly inhibited the ability of surfactant to reduce surface tension upon compression. We found that adverse effects of cigarette smoke on surfactant were induced by tar, which is the product of burning, and other major components of cigarette smoke (nicotine, acetaldehyde, and isoprene) did not cause surfactant disruption. This observation explains why e-cigarette vapor does not inhibit surfactant function, since e-cigarette involves vaporization, but not burning.

Compression of surfactant results in the formation of a microstructure, which is the result of changes in surfactant molecular organization. A hill and valley structure starts to appear insurfactant upon compression and get larger as surfactant is further compressed. It was found that e-cigarette vapor affects this microstructure, resulting in wider, and more frequent hills (Figure 1）。虽然我们仍然未知这种表面活性剂结构的重要性，但该观察结果表明，暴露于电子烟后确实会发生表面活性剂的略有变化，并且如果使用较高剂量的电子烟蒸气，则可能导致表面张力的变化。

电子烟比常规吸烟的破坏性较小

电子烟蒸气不会改变表面活性剂减少表面张力的能力，而是会影响其微观结构。尽管与常规香烟相比，电子烟对表面活性剂的破坏性明显较小，但暴露于电子烟蒸气后观察到的表面活性剂功能的变化不应被视为缺乏肺毒性。尚不清楚电子烟是否会影响细胞或其分泌的表面活性剂的产生。需要对电子烟蒸气对表面活性剂产生，分泌和功能的影响进行全面研究，以更好地了解电子烟的肺毒性。