Repetitive Exposure to Nicotine-Free Vaping Impairs Airway Defences and Delays Recovery

Area of Science:

• Pulmonary Medicine
• Toxicology
• Cell Biology

Background:

• E-cigarette use (vaping) is rising, particularly among adolescents.
• Limited data exists on e-cigarette aerosol effects on lung health and airway defense mechanisms.
• This study investigates the impact of repeated nicotine-free e-cigarette aerosol exposure on airway protective functions.

Purpose of the Study:

• To examine how repetitive exposure to nicotine-free e-cigarette aerosols disrupts airway protective functions.
• To assess the recovery capacity of airway defense mechanisms after such exposures.

Main Methods:

• Primary nasal airway cells from healthy individuals were repeatedly exposed to e-cigarette aerosols.
• Cilia function was analyzed using high-speed video microscopy.
• Epithelial barrier integrity was assessed via trans-epithelial electrical resistance and immunofluorescence.
• Cytokine secretion was measured using multiplex screening.

Main Results:

• Significant impairment of cilia function and epithelial barrier integrity occurred after 24+ vaping exposures.
• Cilia beating frequency decreased by up to 53.0% and barrier integrity by 77.4% after 60 sessions (p < 0.01).
• Nicotine-free aerosols disrupted key proteins (Occludin-1, ZO-1) and increased inflammatory cytokine secretion; recovery took 48-72 hours.

Conclusions:

• Progressive, repetitive vaping impairs in vitro airway protective functions.
• Short-term recovery of cilia and epithelial integrity is possible but delayed.
• The recovery delay could heighten susceptibility to respiratory infections.