Development of a Biomimetic Human Airway Epithelial Barrier-on-a-chip
and Ex Vivo Human Airway Model: Tools for Evaluating Silica PM 2.5
Particle Exposure
Abstract
Background and objective Exposure to inorganic dust and
particulate matter (PM) disrupts the integrity and function of the
airway epithelial barrier (AEB). Herein, the immune response and
epithelial barrier integrity disruption effect of respirable ex vivo
airway tissue models. Methods Particles at an average size of 1
µm, referred to as ex vivo. Computational fluid dynamics simulations
were performed to assess shear stress profiles under different flow
conditions. WST-1, LDH, SEM, ELISA, IF and qRT-PCR analyses were carried
out to evaluate cell survivability, morphology, barrier integrity and
inflammation. Results In AEB-on-a-chip platform, the exposure
to PM2.5 dusts disrupted AEB integrity via decreasing cell
adhesion-barrier markers such as ZO-1, Vinculin, ACE2 and
CD31, impaired cell viability and increased the expression levels
of proinflammatory markers; IFNs, IL-6, IL-1s, TNF-α, CD68, CD80,
and Inos, mostly under dynamic conditions. Besides, decreased
tissue viability, impaired tissue integrity via decreasing of
Vinculin, ACE2, β-catenin and E-cadherin, and also
proinflammatory response with elevated CD68, IL-1α , IL-6,
IFN-Ɣ, Inos and CD80 markers, were observed after PM2.5
dust exposure in ex vivo tissue. Conclusion The
disruption of the barrier integrity and subacute immune response upon
silica PM2.5 exposures is nicely demonstrated by both AEB-on-a-chip
platform emulating dynamic forces in the body and resident immune cells
containing ex vivo bronchial biopsy slices. Airborne dust
pollutants pose a significant future respiratory hazard for human
airways under climate change conditions and Lung-on-a-Chip Models will
serve as reliable substitutes in this context.