In the human body, highly organized tissues rely on the compartmentalization effect of basement membranes (BMs) that separate different types of cells. We recently reported an artificial basement membrane (A-BM) composed of type-IV collagen and laminin (Col-IV/LM), which are the main components of natural BMs, for cell compartmentalization in three-dimensional (3D) tissues. However, such compartmentalized structures can be maintained only for 3 days, probably due to the degradation issues. In this study, a robust A-BM was fabricated by in situ cross-linking the Col-IV/LM layer-by-layer (LbL) nanofilms in 3D tissues by transglutaminase. The effects of molecular size and configuration on the permeability of obtained A-BMs were comprehensively studied using polystyrene nanoparticles (PS NPs) and dextran with various hydrodynamic diameters, as well as albumin. The findings agreed well with the known size-selective behavior of the glomerular basement membrane. Cross-linked Col-IV/LM nanofilms demonstrate improved stability and a more powerful barrier effect to maintain cell compartmentalization for organized 3D tissues. This in vitro A-BM exhibit great potentials for the design of more complex compartmentalized 3D tissues, for understanding the unique cell–cell cross talk through BMs, and for providing a more reliable 3D tissue model for new drug screening and other in vitro physiological studies.

中文翻译：

---

3D组织中人工基底膜的原位交联及其与尺寸有关的分子渗透性

在人体中，高度组织化的组织依赖于分隔不同类型细胞的基底膜（BMs）的分隔作用。我们最近报道了由IV型胶原蛋白和层粘连蛋白（Col-IV / LM）组成的人工基底膜（A-BM），它们是天然BMs的主要成分，用于在三维（3D）组织中进行细胞分隔。但是，可能由于降解问题，这种分隔的结构只能维护3天。在这项研究中，通过转谷氨酰胺酶在3D组织中原位交联Col-IV / LM逐层（LbL）纳米膜，制造出了坚固的A-BM。使用聚苯乙烯纳米颗粒（PS NPs）和具有不同流体动力学直径的葡聚糖，全面研究了分子大小和构型对所得A-BMs渗透性的影响，以及白蛋白。这些发现与肾小球基底膜的已知大小选择行为非常吻合。交联的Col-IV / LM纳米膜表现出更高的稳定性和更强大的阻隔作用，可维持组织化3D组织的细胞区室化。这种体外A-BM在设计更复杂的分隔3D组织，理解通过BM的独特细胞间串扰以及为新药筛选和其他体外生理学研究提供更可靠的3D组织模型方面显示出巨大潜力。 。