Journal of Aerosol Medicine and Pulmonary Drug Delivery

Yara‐Maria Proust, Andreas Stucki, Nicole Schneider‐Daum, Claus‐Michael Lehr, Tobias Krebs, Olivier Guenat, Janick Stucki & Nina Hobi


The pulmonary alveolar barrier is one of the largest surfaces of the human body and constantly exposed to aerosols. Yet, the available in vitro systems do poorly represent the complex microenvironment of the alveoli. Here, we present a first proof of concept study of a breathing alveolus‐on‐chip exposure model. For that, freshly isolated human alveolar epithelial cells (hAEpC) were seeded on‐chip and cultured in submerged conditions until they reached confluency and tightness. After hAEpCs reached a transepithelial electrical resistance (TEER) above 1’000 Ωcm2, apical medium was removed and cyclic mechanical stretch (8% linear strain at 12 breathing cycles per minute) was applied. Stretched and non‐stretched cells were cultured on the air‐liquid interface for 7 days and subsequently exposed to a moderate amount of zinc oxide nanoparticles using the VITROCELL® Cloud system equipped with a specially designed chip adaptor. Exposure to aerosolized phosphate buffered saline solution served as control. 24 hours post‐exposure, cells were stained with a live/dead dye and supernatants were collected for a comprehensive lactate dehydrogenase activity testing and cytokine measurements. First results are indicating that stretched cells are more susceptible to nanoparticle exposure. Future on‐chip exposure experiments, examining different aerosols and exposure protocols, will reveal the utility of the breathing alveolus on‐chip as a novel in vitro inhalation tool.