A microfluidic lung-on-a-chip based on biomimetic hydrogel membrane

Lung-on-chips have showed great promise as a tool to recapitulate the respiratory system for investigation of lung diseases in the past decade. However, the commonly applied artificial elastic membrane (e.g., polydimethylsiloxane, PDMS) in the chip failed to mimic the alveolar basal membrane in the composition and mechanical properties. Here we replaced the PDMS film by a thin, biocompatible, soft, and stretchable membrane based on F127-DA hydrogel that well approached to the composition and stiffness of extracellular matrix in human alveoli for construction of lung-on-a-chip. This chip well reconstructed the mechanical microenvironments in alveoli so that the epithelial/endothelial functions were highly expressed with a well established alveolar-capillary barrier. In opposite to the unexpectedly accelerated fibrotic process on the PDMS-based lung-on-a-chip, HPAEpiCs on hydrogel-based chip only presented fibrosis under nonphysiologically high strain, well reflecting the features of pulmonary fibrosis in vivo. This physiologically relevant lung-on-a-chip would be an ideal model in investigation of lung diseases and for development of antifibrosis drugs.