An Insert-Compatible Magnetic Actuation Platform for Dynamic Air–Liquid Interface Culture of Human Alveolar Epithelial Cells

Abstract Static air–liquid interface (ALI) culture reproduces apical air exposure but not breathing-associated deformation. We developed an insert-compatible magnetic actuator that cyclically deforms a porous polydimethylsiloxane (PDMS)-supported human alveolar epithelial culture while the culture plate remains lidded and free of pneumatic tubing or mechanical linkages entering the culture chamber. A polyamide-coated NdFeB magnet resting on collagen I was driven by an electromagnet beneath the plate. Short-term screening showed that coating prevented the marked MTT/LDH toxicity of an uncoated magnet. The selected 12 V, 0.2 Hz condition, operated with auxiliary convective cooling, maintained culture medium near 37°C and produced approximately 2.5 mm central displacement; geometry-based analysis estimated an annular mean strain of 7–16%. Human pulmonary alveolar epithelial cells (HPAEpiCs) were matured at ALI for 7 days and then cultured for 72 h under dynamic, static-ALI, or submerged conditions. Dynamic ALI showed higher apparent transepithelial electrical resistance than static ALI at 72 h (1780 ± 140 vs. 1634 ± 120 Ω·cm²; n = 9; p = 0.0304). At the matched 72 h endpoint, dynamic ALI also expressed the AT1-associated marker AQP5 4.3-fold higher than static ALI (p < 0.001), and whole-mount immunofluorescence confirmed retention of concurrent AT1- and AT2-associated features. The platform provides a compact route to add breathing-like mechanical input to an insert-based alveolar ALI workflow while preserving conventional barrier and molecular readouts.