Chondrocyte Viability and Function is Impaired by E-Cigarette Liquid Flavor Additives

Environmental factors, such as inhaled chemical agents, may pose risks to cartilage tissue and embedded chondrocytes. Increasingly used among adolescents and young adults, electronic cigarettes (e-cigarettes) utilize aerosols rich in chemical flavoring agents that contact the respiratory epithelium and may adversely affect underlying airway structures, including chondrocyte-containing cartilage. This study evaluated the effect of common e-cigarette flavorings on chondrocyte viability and function using the ATDC5 cell line as a chondrocyte model.

ATDC5 cells were exposed to increasing concentrations of nicotine-free e-cigarette liquid flavor additives (ELFAs) introduced into the media, followed by assessment of cellular metabolism, cellular membrane integrity, functional activity, inflammatory response, and gene expression profiling.

Significant cytotoxicity was observed in Cinnamon- and Menthol-treated groups, with near-complete loss of cell viability at concentrations ≥4%. These additives also induced dysregulation of chondrocyte matrix metabolism and increased expression of cyclo-oxygenase-2 activity, notably displaying significant upregulation of matrix metalloproteinase-13 (MMP-13) and prostaglandin E₂, respectively.

Our findings show that commonly used ELFAs may alter chondrocyte metabolism, function, gene expression, and inflammatory signaling in a flavor‑ and concentration‑dependent manner, underscoring the need for deeper investigation into how e‑cigarette flavor additives affect cellular and tissue health.