An Immune Microenvironment-Integrated Intestinal-on-a-Chip Model for Investigating Immunopathogenesis in Inflammatory Bowel Disease.

Owing to the multifactorial nature of inflammatory bowel disease (IBD) pathogenesis, conventional two-dimensional (2D) models inadequately recapitulate the complex in vivo microenvironment. This study sought to develop an immune-microenvironment-integrated intestinal-on-a-chip model to overcome these limitations. A microfluidic chip was engineered to co-culture intestinal epithelial (Caco-2) cells and macrophages, facilitating the simulation of IBD pathological conditions for mechanistic investigations. Following inflammatory stimulation, M0 macrophages polarized into the M1 phenotype, concomitant with the upregulation of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β). This induction disrupted the expression of tight junction proteins (e.g., zonula occludens-1 [ZO-1]) in Caco-2 cells, thereby compromising epithelial barrier integrity. Infliximab was used as a model drug to inhibit TNF-α and modulate macrophage polarization within the chip, effectively rescuing impaired epithelial barrier integrity. This study establishes a reliable intestinal-on-a-chip model that recapitulates macrophage-epithelial interactions in IBD, providing a robust platform for elucidating the mechanisms underlying intestinal barrier dysfunction and developing targeted therapeutic strategies.