A tape-based intestinal chip co-culture model for assessing anti-inflammatory activity of chitosan oligosaccharides

Intestinal inflammation is a central pathological process in gastrointestinal diseases, yet conventional in vitro models poorly reproduce epithelial-immune interactions, and accessible platforms for rapid anti-inflammatory screening remain lacking. Here, a low-cost, high-throughput tape-based intestinal chip co-culturing Caco-2 epithelial cells and RAW264.7 macrophages under dynamic flow was applied to approximate the epithelial-macrophage interface of the intestinal wall and to evaluate the anti-inflammatory activity of chitosan oligosaccharides (COS). Three COS fractions (COS1, COS2, COS3; 3.6, 2.7, and 0.8 kDa) prepared from Antarctic krill shell exhibited molecular weight-dependent transepithelial permeability, with COS3 showing the highest permeability. All COS fractions significantly suppressed LPS-induced NF-κB p65 nuclear translocation, macrophage morphological activation, and the production of NO, IL-1β, TNF-α, and IL-6, with the low-molecular-weight COS3 showing the strongest effects under equal-mass dosing. Targeted metabolomics identified four candidate marker metabolites (proline, asparagine, GTP, and α-ketoglutaric acid) that were elevated by LPS and partially restored by COS treatment, providing a metabolic signature for rapid evaluation of anti-inflammatory efficacy. These findings establish the integrated tape-based chip-metabolomics strategy as an accessible platform for screening anti-inflammatory bioactive compounds and highlight the potential of low-molecular-weight COS as anti-inflammatory agents.