2.11 Permeability monitoring of alveolar-capillary barrier on
the chip
The permeability of the alveolar-capillary barrier on the chip was
assessed by measuring the diffusion rate of FITC-dextran (40 kDa,
purchased from Thermo, USA) from the upper vascular layer to the lower
alveolar compartment. Following smoke exposure, media with FITC-dextran
were added to the upper channels. Samples from the lower chambers were
collected at set intervals (0 and 60 min), and their fluorescence
intensities were measured with a plate reader. This rate was computed to
ascertain barrier permeability. Real-time observation of fluorescence in
the lower layer was also performed to assess permeability through the
chip’s transparent sections.