Impact of E-Cigarette Exposure on Wound Healing After Surgical Vocal Fold Injury in Mice.

Abstract

Surgical manipulation of the vocal folds carries a risk of mucosal injury. We used an established unilateral mouse vocal fold injury model to determine whether electronic cigarette (E-cig) exposure after injury induces remodeling and inflammatory responses in the vocal fold mucosa that differ from injury alone. Adult mice underwent unilateral vocal fold injury using a wire brush under microscopy and were assigned to an Injury or Injury + E-cig group. The Injury + E-cig group received daily E-cig aerosol exposure after injury. Mice were sacrificed at 3, 14, and 28 days. A room air-exposed group served as Control. We quantified epithelial (EP) thickness and lamina propria (LP) area, measured expression of genes related to EP junctions, extracellular matrix (ECM) remodeling, and inflammation, and performed immunostaining to corroborate gene expression findings. Injury + E-cig mice exhibited blunted post-injury weight gain versus Controls. EP thickness and EP junction gene expression recovered similarly in Injury and Injury + E-cig groups. In contrast, early LP expansion and acute increases in TNF-α, F4/80, and Col3α1 were attenuated with E-cig exposure, indicating selective disruption of acute macrophage-associated inflammatory and ECM responses. This is the first study to examine the effects of E-cig exposure on vocal fold wound healing. Clinically, these findings raise concern about postoperative E-cig use after vocal fold surgery. Although often viewed as safer than smoking, E-cig use may alter early wound healing responses that are essential for restoring vocal fold structure and function. N/A.