Microfluidic Pulmonary System for Experimental Investigation of Cellular Injury due to Fluid Mechanical Stresses during Airway Reopening.

Airway closure and reopening are characteristic of a variety of pulmonary diseases. Unique microscale air-liquid two-phase fluid motions during airway reopening generate large mechanical stresses, which may be deleterious to airway epithelial cells in the small airway system. Here we describe micro-engineered biomimetic in vitro airway systems and injury of pulmonary epithelial cells due to fluid mechanical stresses imposed by airway reopening. Using compartmentalized microchannel networks fabricated by soft lithography, we demonstrated long-term microfluidic culture of pulmonary epithelial cells. Airway reopening was reproduced in the microchannels by using air-liquid two-phase microfluidic systems that use air bubbles to form liquid plugs. We found that plug propagation and rupture during airway reopening cause cellular injury by exerting high levels of fluid mechanical stresses on pulmonary epithelial cells. [ABSTRACT FROM AUTHOR]