Integrated microfluidic three-organ chip for real-time toxicity analysis of fluorotelomer alcohols in the gut–vascular–nerve axis

systems due to their inability to recapitulate multi-organ interactions. To address this limitation, we developed and engineered a tri-organ gut-vascular-nerve axis chip that reconstructs the bidirectional gut-brain communication through an integrated endothelial barrier. Unlike dispersed 2D cultures on D-polylysine plates, our 3D platform supports cross-linked neurite outgrowth, self-assembled microvascular tubules, and a tightly sealed intestinal epithelia, coupled with integrated solid-phase extraction-mass spectrometry for real-time tracking of PFAS dynamics. We demonstrate that intestinal epithelial cells metabolize fluorotelomer alcohols into bioactive fluorotelomer carboxylic acids, which may transit vascular channels to neural compartments, inducing neuronal dysfunction and driving axis-wide alterations in metabolic activity, oxidative stress responses, and inflammatory signaling. This physiologically relevant model provides novel mechanistic insights into PFAS neurotoxicity and establishes a robust organ-on-chip paradigm for environmental toxicology.