Electronic cigarettes: do they present health hazards?

描述(由申请人提供)：*方括号[--]表示研究培训计划中已更改的部分*电子烟(EC)是尼古丁传递装置，通常宣传为戒烟。最近进入消费市场的EC设备正迅速在全球范围内流行起来。EC部件包括：一个装有尼古丁液体的口罩、一个用于加热的雾化器和一个电池。弹药筒的液体各不相同，通常含有一定浓度的尼古丁、保湿剂，如丙二醇和各种调味品。EC社区的一个明显趋势是，通过将重新填充的液体滴入空盒中来重新填充尼古丁溶液。尽管EC越来越受欢迎，但很少进行科学研究来评估EC气雾剂对使用者或旁观者的可能健康影响，目前尚不清楚EC是否构成健康问题。EC中使用的调味品通常是食品添加剂和香水，它们不是用来加热和吸入的，对人类健康有未知的后果。我的长期目标是描述EC使用对人类健康的影响。这项建议特别关注EC再灌装液体气雾剂的细胞毒性。我将首先(目标1)使用人胚胎干细胞(HESC)和人肺成纤维细胞(Hpf)来评估不同来源EC再充液气雾剂的细胞毒性。 制造商。细胞毒性的筛选将使用四甲基偶氮唑盐细胞活力试验和代谢试验。这第一步将确定可能对人类健康产生不利影响的EC产品。其次(目标2)，我将使用气相色谱和质谱仪来鉴定EC气雾剂中的有毒化学物质。然后，将购买每一种确定的化学品，并使用带有hESC和HPF的四甲基偶氮唑蓝试验进行分析。识别这些产品中的有毒物质将使制造商能够去除它们，并让用户意识到潜在的危险产品。然后，我将为EC重新填充流体气雾剂和已识别的 化学制品。[最后，我将验证EC气雾剂和已识别的化学物质诱导活性氧物种(ROS)，从而导致DNA损伤和细胞凋亡的假设。为了测试这一点(目标3)，将使用和不使用维生素E(一种ROS抑制剂)对细胞毒性最强的气雾剂和化学品进行筛选，以使用延时数据和荧光ROS检测器评估ROS的诱导。为了确定ROS增加是否会导致DNA损伤，将使用碱性彗星试验和免疫细胞化学来评估DNA断裂。对于导致氧化应激并具有遗传毒性的气雾剂和化学品，将结合细胞凋亡指标分析hESC和HPF的时间推移数据。Western blotting和Annexin V分析将用于验证凋亡途径蛋白的激活。]这将是第一次大规模的评估 EC再灌装液体气雾剂的细胞毒性。这项拟议的研究将收集有价值的数据，以深入了解这些产品中哪些是不安全的，哪些剂量会产生细胞毒性和基因毒性效应，哪些特定的化学物质是有毒的，最后，哪些产品可能会 对用户的健康造成不利影响。

DESCRIPTION (provided by applicant): *Square brackets [--] indicate parts of the Research Training Plan that have been changed* Electronic cigarettes (EC) are nicotine delivery devices, often advertised for smoking cessation. Recently released into the consumer marketplace, EC devices are quickly becoming popular worldwide. EC parts include: a mouthpiece housing a cartridge of nicotine-containing fluid, an atomizer used for heating, and a battery. The cartridge fluids vary, typically containing some concentration of nicotine, a humectant, such as propylene glycol, and various flavorings. One visible trend in the EC community is to refill the nicotine solution by dripping refill fluid into an empty cartridge. In spite of EC growing popularity, few scientific studies have been conducted to assess possible health effects of EC aerosol on users or bystanders, and it remains unclear if EC pose a health concern. Flavorings used in EC are often food additives and perfumes, which are not intended to be heated and inhaled and which have unknown consequences on human health. My long-term objective is to characterize the effects of EC use on human health. This proposal specifically focuses on the cytotoxicity of EC refill fluid aerosol. I will first (Aim #1) use human embryonic stem cells (hESC) and human pulmonary fibroblasts (hPF) to evaluate the cytotoxicity of EC refill fluid aerosols from different manufacturers. Screening for cytotoxicity will be done using the MTT cell viability assay and a metabolizing assay. This first step will identify EC products that may produce adverse health effects in humans. Secondly (Aim #2), I will use gas chromatography and mass spectrometry to identify toxic chemicals in EC aerosols. Each chemical identified will then be purchased and analyzed using the MTT assay with hESC and hPF. Identification of toxicants in these products would allow manufacturers to remove them and make users aware of potentially dangerous products. I will then create a hierarchy of potency for EC refill fluid aerosols and the identified chemicals. [Finally, I will test the hypothesis that EC aerosols and the identified chemicals induce reactive oxygen species (ROS), which lead to DNA damage and apoptosis. To test this (Aim #3), the most cytotoxic aerosols and chemicals will be screened with and without vitamin E (a ROS inhibitor) to assess induction of ROS using time-lapse data and fluorescent ROS detectors. To determine if increased ROS leads to DNA damage, the alkaline comet assay and immunocytochemistry will be used to assess breaks in DNA. For aerosols and chemicals that induce oxidative stress and are genotoxic, time-lapse data will be analyzed for hESC and hPF in conjunction with apoptotic indicators. Western blotting and the Annexin V assays will be used to verify activation of the apoptotic pathway proteins.] This will be the first large-scale assessment of cytotoxicity in EC refill fluid aerosols. The proposed study will collect valuable data that wil provide insight into which of these products are unsafe, the doses that produce cytotoxic and genotoxic effects, the specific chemicals that are toxic, and finally, which products are likely to adversely affect the health of users.