Engineering a 3D Lung Co-culture Platform to Model Epithelial-Fibroblast Interactions in Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease (ILD) characterized by progressive fibrosis, irreversible loss of lung elasticity, and chronic respiratory failure, with a mean survival of 3-5 years. The disease is believed to result from repeated alveolar epithelial injury that sustains transforming growth factor-beta (TGF-{beta}) signaling, driving fibroblast-to-myofibroblast differentiation and excessive collagen deposition. Although current IPF models--including animal studies, 2D cultures, and basic 3D systems--have enhanced understanding of disease mechanisms, they inadequately replicate epithelial-fibroblast interactions, extracellular matrix (ECM) remodeling, and epithelial barrier dysfunction. To address this limitation, we engineered a 3D lung co-culture model that simulates the physiological epithelial-fibroblast crosstalk and ECM remodeling characteristic of IPF. Our model embeds fibroblasts within a collagen-hyaluronic acid matrix overlaid with an epithelial monolayer cultured at an air-liquid interface. Basolateral TGF-{beta} exposure generated a profibrotic microenvironment that weakened epithelial barrier integrity and drove myofibroblast differentiation marked by elevated -SMA and vimentin. Elevated pro-inflammatory cytokine secretion and increased collagen disorganization further demonstrated active fibrogenesis. Together, these features show that our model captures key early events in IPF pathogenesis and offers a versatile platform for next-generation lung-on-a-chip studies in fibrotic disease.