Exposure on a chip to better design aerosolised drug delivery deep into the lungs

目前尚不清楚脆弱的肺泡上皮-毛细血管内皮屏障的结构和功能以及它在并列的组织层之间的相互作用如何赋予我们必要的完整性和选择性的通透性来保护我们。我们假设，呼吸屏障的完整性和功能关键依赖于并列的肺泡上皮和肺泡内皮之间的有效沟通。如果这种沟通因外部因素(如吸入毒素)或内源性因素(如血流/压力剪切变化)而受到损害，就会失去屏障的完整性并增加通透性。我们在分子水平上的理解可以通过体外机制研究来加强；但由于缺乏相关的体外模型与先进的定量成像技术相结合来测量实时分子相互作用，这一点受到了阻碍。我们建议的主要目的是开发一种独特而灵活的人肺泡气-血界面的动态微流体3D组织模型，耦合到一个先进的成像平台，能够在纳米级实时(4D)分辨活细胞事件，同时监测促炎症条件和生理应激条件下跨皮/跨内皮屏障的功能完整性和通透性(这些将通过对AOC中的3D复杂细胞模型造成损伤来实现)。为此，我们将把微流控AOC集成到高分辨率活细胞成像平台(AOC-HRIP)中，以研究呼吸系统的病理生理情景。我们的AOC-HRIP模型将i)处理生理3D分层和相互连接的人类呼吸屏障模型；ii)监测功能屏障的完整性和渗透性；iii)在不同的暴露和呼吸制度下以正确的长度和时间尺度实时跟踪所涉及的分子机制。

It is not known how the structure and function of the fragile alveolar epithelial-capillary endothelial barrier and its crosstalk between the juxtaposed tissue layers confers the essential integrity and selective permeability to protect us. We hypothesise that respiratory barrier integrity and function critically depends on effective communication between the juxtaposed alveolar epithelium and alveolar endothelium. If this communication is compromised due to external (e.g., inhaled toxins) or endogenous (e.g., changes in blood flow/pressure-shear) factors, there will be loss of barrier integrity and increased permeability. Our understanding at the molecular level could be enhanced using mechanistic in vitro studies; but this is hampered by the lack of relevant in vitro models in combination with advanced quantitative imaging techniques to measure real-time molecular interactions. The main aim of our proposal is to develop a unique and flexible dynamic microfluidic 3D tissue model of the human alveolar gas-blood interface coupled into an advanced imaging platform, capable of resolving live-cell events in real-time (4D) at the nanoscale and, simultaneously, to monitor the functional integrity and permeability of the transepithelial/transendothelial barrier under proinflammatory conditions and physiological stress (these will be carried out by generating an injury to the 3D complex cellular model in the AOC). For this purpose, we will integrate a microfluidic AOC into a high-resolution live-cell imaging platform (AOC-HRIP) to study respiratory pathophysiological scenarios. Our AOC-HRIP model will i) handle physiologically 3D stratified and interconnected human respiratory barrier models; ii) monitor functional barrier integrity and permeability; and iii) will follow the molecular mechanisms involved in real-time at the correct length and time scales at different exposure and breathing regimes.