Nanoparticle properties and alveolar epithelial barrier/transport functions

项目摘要 吸入超细（纳米）颗粒与不良心血管、肺和 血液学影响、颗粒在血管和终末器官中的定位以及发病率增加， 易感人群的死亡率。由于这些颗粒是被吸入的，它们最有可能进入大气层的途径是： 体循环穿过肺的肺泡上皮。虽然由于纳米颗粒的使用， 纳米技术的科学和应用的扩展预计将显着增加， 纳米颗粒损伤和/或转运进入/穿过肺泡上皮的机制尚不清楚， 知道的基于我们对几类纳米颗粒的肺损伤/摄取/运输的初步数据， （由聚苯乙烯、二氧化硅和金属（氧化物）组成），具有明确的物理化学特性， 关于吸入超细空气污染物颗粒物对健康影响的报告，我们假设 纳米颗粒和肺泡上皮细胞i）可以破坏正常的肺泡上皮细胞稳态， 细胞特性和肺泡上皮屏障功能的变化，ii）提供进入的主要门户， 纳米颗粒通过经上皮易位途径进入体循环，和iii）高度 这取决于纳米颗粒的物理化学性质。利用特定的聚苯乙烯、二氧化硅和金属 在体外模型中（包括我们建立的大鼠或小鼠的原代培养单层细胞）， 人肺泡上皮细胞）和大鼠肺的体内实验，我们将通过研究 以下四个主要目的：1）纳米颗粒对肺泡的主动和被动屏障性能的影响 上皮; 2）肺泡上皮细胞中纳米颗粒的内化、命运和影响; 3） 纳米颗粒在体外穿过肺泡上皮;和4）大鼠肺中的纳米颗粒内化和运输 在体内，与体内和体外的远端呼吸道上皮的损伤/摄取/运输相关。在 此外，我们将利用简化模型的人工脂质双层重建的渗透性过滤器和巨大的 单层囊泡以确定被动机制的作用（例如，扩散）和/或脂质的破坏 纳米颗粒进入/离开肺泡上皮细胞的双层。拟议的调查结果 本文将提供对细胞毒性和纳米颗粒的内化/运输机制的见解， 定义进入/穿过肺泡上皮的理化性质。我们的主要目标是 关于纳米颗粒与肺泡上皮相互作用的新信息，以帮助了解对 肺吸入制造的纳米颗粒和环境空气污染物超细颗粒，点 指导管理所产生的有害影响，并导致改进设计的定义 用于更安全和更有效的生物医学应用的纳米颗粒（例如，肺部药物/基因递送）。

PROJECT SUMMARY Inhalation of ultrafine (nano)particles has been associated with adverse cardiovascular, pulmonary and hematologic effects, localization of particles in blood vessels and end organs, and increased morbidity and mortality in susceptible populations. Since the particles are inhaled, their most likely route of entry into the systemic circulation is across the alveolar epithelium of the lung. Although utilization of nanoparticles due to expansion of the science and application of nanotechnology is expected to markedly increase, the mechanisms by which nanoparticles injure and/or are transported into/across alveolar epithelium are not well known. Based on our preliminary data on lung injury/uptake/trafficking of several classes of nanoparticles (composed of polystyrene, silica and metal (oxides)) with defined physicochemical characteristics and recent reports on health effects of inhaled ultrafine air pollutant particulates, we hypothesize that interactions between nanoparticles and alveolar epithelial cells i) can disrupt normal alveolar epithelial cell homeostasis and induce changes in cellular properties and alveolar epithelial barrier function, ii) provide the primary portal of entry for nanoparticles into the systemic circulation via transepithelial translocation pathways, and iii) are highly dependent on physicochemical properties of the nanoparticles. Utilizing defined polystyrene, silica and metal (oxide) nanoparticles in in vitro models (including our well-established primary cultured monolayers of rat or human alveolar epithelial cells) and rat lungs in vivo, we will test these hypotheses by investigating the following four major aims: 1) nanoparticle effects on active and passive barrier properties of alveolar epithelium; 2) internalization, fate and effects of nanoparticles in alveolar epithelial cells; 3) trafficking of nanoparticles across alveolar epithelium in vitro; and 4) nanoparticle internalization and trafficking in rat lungs in vivo, correlating injury to/uptake into/trafficking across distal respiratory epithelium in vivo vs in vitro. In addition, we will utilize simplified models of artificial lipid bilayers reconstituted on permeable filters and giant unilamellar vesicles to determine the role(s) of passive mechanisms (e.g., diffusion) and/or disruption of lipid bilayers in nanoparticle entry into/exit from alveolar epithelial cells. Findings from the investigations proposed herein will provide insights into cytotoxicity and mechanisms of internalization/trafficking of nanoparticles with defined physicochemical properties into/across the lung alveolar epithelium. Our major objective is to obtain new information on nanoparticle interactions with alveolar epithelium in order to help understand effects on the lung of inhaled manufactured nanoparticles and environmental air pollutant ultrafine particulates, point directions for management of resultant deleterious effects, and lead to improved design of defined nanoparticles for safer and more efficient biomedical applications (e.g., pulmonary drug/gene delivery).