Core–Shell Nanofibrous Membranes for Dynamic Intestinal Organ-on-a-Chip Culture

Abstract Organ-on-a-chip (OOC) systems rely on membrane-supported tissue interfaces to replicate organ-level barrier functions in vitro. However, conventional porous membranes often provide limited biological cues for cell adhesion and may require an extracellular matrix coating. Here, we developed core–shell nanofibrous porous membranes via coaxial electrospinning, using polycaprolactone (PCL) as the structural core and gelatin as the bioactive shell. These membranes were integrated as replaceable inserts into a commercial dual-channel intestinal chip. Using identical chip geometry and membrane material, we compared three culture regimens: static culture, gravity-driven oscillatory flow, and continuous low-shear perfusion. The C-PCL/Gel membrane exhibited suitable mechanical stability, hydrophilicity, cytocompatibility, and cell-adhesion performance for epithelial–endothelial coculture. In the intestinal barrier model, continuous low-flow perfusion yielded the most favorable outcomes, including transepithelial electrical resistance (TEER) values exceeding 500 Ω·cm2, reduced tracer permeability, more continuous zonula occludens-1 (ZO-1) junctional staining, denser F-actin networks, and altered mucin 2 (MUC2) distribution. These improvements likely arise from combined effects of continuous medium renewal, enhanced mass transport, waste removal, and low-level hydrodynamic stimulation. This membrane-integrated chip provides a practical platform for studying intestinal barrier formation under different fluidic regimens, offering a biomimetic alternative to conventional membrane interfaces.