Biomimetic human lung alveolar interstitium chip with extended longevity

Determining the mechanistic causes of lung diseases, developing new treatments thereof, and assessing toxicity whether from chemical exposures or engineered nanomaterials would benefit significantly from a preclinical human lung alveolar interstitium model of physiological relevance. The existing preclinical models have limitations because they fail to replicate the key anatomical and physiological characteristics of human alveoli. Thus, a human lung alveolar interstitium chip was developed to imitate key alveolar microenvironmental factors including: an electrospun nanofibrous membrane as the analogue of the basement membrane for co-culture of epithelial cells with fibroblasts embedded in 3D collagenous gels; physiologically relevant interstitial matrix stiffness; interstitial fluid flow; and 3D breathing-like mechanical stretch. The biomimetic chip substantially improved epithelial barrier function compared to transwell models. Moreover, the chip having a gel made of a collagen I-fibrin blend as the interstitial matrix sustained the interstitium integrity and further enhanced the epithelial barrier resulting in a longevity that extended beyond eight weeks. The assessment of multiwalled carbon nanotube toxicity on the chip was in line with the animal study.