Identifying vaping hazards through the evaluation of exposure methods and cell culture models for e-liquid mixtures.

Vaping has become a popular method of engaging in “smokeless” socialization since the introduction of e-cigarettes in the United States tobacco market. In 2007, e-cigarettes were presented as portable vaping devices serving as alternatives to traditional tobacco cigarettes. Due to the evolution of technology and the addition of unique e-liquid formulations (i.e., the liquid used in an e-cigarette or similar device), e-cigarettes have captured the attention of youth. E-cigarette usage in youth is a public health concern considering the number of reported underage usage and rapid onset of lung illnesses contributing to hospitalizations, such as EVALI (e-cigarette or vaping product-use associated lung injury). As a result, steps have been made to identify the chemicals in e liquids that induce toxicity. Due to the complexity of e-cigarettes, there is a continued need to implement interdisciplinary approaches for hazard identification of vaping toxicity, namely the evaluation of exposure methods and in vitro model systems. This dissertation introduces a combination of exposure techniques for hazard identification of e-liquid binary mixtures using lung cell models. This work aims to address three critical areas: (1) utilize previously established mathematical mixture modeling for chemical interaction analysis of binary mixtures, (2) collect the condensates of heated vaping products for cytotoxicity screening, and (3) compare the effects of liquid inoculation versus direct aerosol exposure of vaping binary mixtures to cells. The findings show that certain e-liquid ingredients (such as flavoring chemicals and diluents) can lead to changed cytotoxicity over a dose-response relationship when combined at different ratios. Mathematical mixture modeling shows that when these chemicals are simultaneously exposed, they contribute to toxicological antagonism. The collection of condensates proves to be successful for pooling heated e-liquids, and after exposure to cells, cell viability decreases, and oxidative stress increases. Lastly, qualitative and quantitative results show that different exposure methods induce different epithelial barrier integrities. These studies promote the inclusion of multiple exposure methods and cell culture model systems for continued assessment of vaping-induced toxicity.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2025

Author dc:creator

• Baldovinos, Yanira Margarita, 1998-

Advisor dc:contributor.advisor

• Sayes, Christie M.

• eLiquids.
• Lung cells.
• Chemical interactions.
• Condensate.
• Cytoxicity.
• Barrier integrity.
• Electron microscopy.
• Fluorescence microscopy.

Statement dc:rights

• Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/13769

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/13769