Crohn's Disease and Ulcerative Colitis, the main types of Inflammatory Bowel Disease (IBD), are life-threatening gastrointestinal disorders with no definitive cure. The establishment of biorelevant in vitro models that closely recapitulate the IBD microenvironment is of utmost importance to validate newly developed IBD therapies. To address the existing flaws in the current representation of the IBD microenvironment, we propose a novel three-dimensional (3D) in vitro model comprising a multi-layered gastrointestinal tissue with functional immune responses under inflammatory conditions. The multi-layered architecture consists of a lamina propria-like hydrogel with human intestinal fibroblasts (HIF), supporting an epithelial layer composed of Caco-2 and HT29-MTX cells, along with an endothelial layer surrogating the absorptive capillary network. A collagen-alginate composite matrix was optimized for the lamina propria-like hydrogel, preserving HIF metabolic activity and morphology over time. To achieve immune competence, pre-differentiated THP-1-derived macrophages were incorporated into the epithelial barrier. Inflammation was induced through the optimization of an inflammatory cocktail consisting of E. coli O111:B4 lipopolysaccharide combined with a specialized cytokine array (tumor necrosis factor-α, interferon-γ, and interleukin-1β). This inflammation-inducing stimulus led to a significant upregulation of pro-inflammatory cytokines commonly associated with IBD onset, including CCL20, IL-6, CXCL9 and CXCL10. Altogether, this 3D in vitro model has the potential to accelerate the drug development pipeline by providing reliable permeability and efficacy outputs for emerging therapies, reducing unnecessary animal experiments. Moreover, it offers a valuable in vitro platform for studying IBD pathophysiology and cell interplay dynamics.

中文翻译：

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炎症性肠病 3D 多层体外模型的建立


克罗恩病和溃疡性结肠炎是炎症性肠病 （IBD） 的主要类型，是危及生命的胃肠道疾病，没有明确的治愈方法。建立紧密概括 IBD 微环境的生物相关体外模型对于验证新开发的 IBD 疗法至关重要。为了解决当前 IBD 微环境表示中的现有缺陷，我们提出了一种新的三维 （3D） 体外模型，该模型由多层胃肠道组织组成，在炎症条件下具有功能性免疫反应。多层结构由具有人肠成纤维细胞 （HIF） 的固有层状水凝胶组成，支撑由 Caco-2 和 HT29-MTX 细胞组成的上皮层，以及替代吸收毛细血管网络的内皮层。胶原-海藻酸盐复合基质针对固有层样水凝胶进行了优化，随着时间的推移保持 HIF 代谢活性和形态。为了获得免疫能力，将预分化的 THP-1 衍生的巨噬细胞掺入上皮屏障中。通过优化由大肠杆菌 O111：B4 脂多糖结合特殊细胞因子阵列 （肿瘤坏死因子-α、干扰素-γ 和白细胞介素-1β） 组成的炎症鸡尾酒来诱导炎症。这种炎症诱导刺激导致通常与 IBD 发作相关的促炎细胞因子显着上调，包括 CCL20、IL-6、CXCL9 和 CXCL10。总而言之，这种 3D 体外模型有可能通过为新兴疗法提供可靠的渗透性和疗效输出来加速药物开发管道，从而减少不必要的动物实验。 此外，它为研究 IBD 病理生理学和细胞相互作用动力学提供了一个有价值的体外平台。