小肠是一个复杂的器官,具有特征性的结构和药物和营养吸收的主要部位。组织在称为绒毛的手指状突起中的三维(3D)形貌显着增加了表面积,给予更有效的吸收过程。肠粘膜,这个过程发生的地方,是多层和多细胞型组织屏障。体外肠道模型通常用于研究肠道中的不同生理和病理过程,包括复合吸收。尽管如此,标准模型通常是二维(2D)的,只代表上皮屏障,缺乏3D架构提供的线索和体内存在的基质成分,往往导致不准确的结果。在这项工作中,我们使用包含上皮和基质区室的肠粘膜生物打印3D模型研究了肠道3D结构对药物转运的影响.将人肠成纤维细胞包埋在先前优化的水凝胶生物墨水中,将肠细胞和杯状细胞接种在顶部以模拟肠粘膜。嵌入的成纤维细胞在水凝胶中茁壮成长,重塑周围的细胞外基质。上皮细胞完全覆盖水凝胶支架并形成具有接近体内的屏障性质的均匀细胞层。特别是,与由相同的水凝胶和细胞组成的扁平对应物相比,绒毛样模型显示出总体上增加的渗透性。此外,与扁平模型相比,绒毛样支架中P-糖蛋白(P-gp)转运蛋白的外排活性显着降低,其他药物转运蛋白的基因表达是,总的来说,与绒毛样模型更相关。全球范围内,这项研究证实了3D结构的存在促进了上皮屏障的更多生理分化,提供更准确的药物吸光度测量数据。
The small intestine is a complex organ with a characteristic architecture and a major site for drug and nutrient absorption. The three-dimensional (3D) topography organized in finger-like protrusions called villi increases surface area remarkably, granting a more efficient absorption process. The intestinal mucosa, where this process occurs, is a multilayered and multicell-type tissue barrier. In vitro intestinal models are routinely used to study different physiological and pathological processes in the gut, including compound absorption. Still, standard models are typically two-dimensional (2D) and represent only the epithelial barrier, lacking the cues offered by the 3D architecture and the stromal components present in vivo, often leading to inaccurate results. In this work, we studied the impact of the 3D architecture of the gut on drug transport using a bioprinted 3D model of the intestinal mucosa containing both the epithelial and the stromal compartments. Human intestinal fibroblasts were embedded in a previously optimized hydrogel bioink, and enterocytes and goblet cells were seeded on top to mimic the intestinal mucosa. The embedded fibroblasts thrived inside the hydrogel, remodeling the surrounding extracellular matrix. The epithelial cells fully covered the hydrogel scaffolds and formed a uniform cell layer with barrier properties close to in vivo. In particular, the villus-like model revealed overall increased permeability compared to a flat counterpart composed by the same hydrogel and cells. In addition, the efflux activity of the P-glycoprotein (P-gp) transporter was significantly reduced in the villus-like scaffold compared to a flat model, and the genetic expression of other drugs transporters was, in general, more relevant in the villus-like model. Globally, this study corroborates that the presence of the 3D architecture promotes a more physiological differentiation of the epithelial barrier, providing more accurate data on drug absorbance measurements.