Interactions of engineered nanomaterials with lung alveolar epithelium

描述（由申请人提供）：尽管由于纳米生物医学/技术的科学和应用的扩展，工程纳米材料（ENM）的应用预计将显著增加，但ENM损伤和/或运输到肺泡上皮的机制尚不清楚。吸入环境超细颗粒（其尺寸范围与当前纳米材料的定义重叠）已被证明会导致不利的心血管、肺部和血液系统影响。如果意外吸入任何ENM，它们最可能进入体循环的途径是穿过肺的肺泡上皮。基于我们正在进行的关于肺损伤和几种具有明确物理化学特征的纳米颗粒（例如聚苯乙烯、二氧化硅和金属（氧化物））的贩运的研究，以及最近关于吸入超细空气污染物颗粒和其他纳米材料（特别是富勒烯及其衍生物）对健康影响的报告，我们假设各种形式的ENM(例如，负极富勒烯与正极富勒烯；原生（疏水）与衍生（亲水）富勒烯；不同质量的富勒烯（例如，C60、C70、C80和聚合富勒烯）和肺泡上皮细胞i)可以破坏正常的肺泡上皮细胞稳态，并以ENM特异性的方式诱导细胞特性和肺泡上皮屏障功能的变化，ii)可以为ENM进入体循环提供主要入口（例如，富勒烯可能通过经上皮易位途径易位）。iii)高度依赖于ENM的物理化学性质（例如富勒烯）。利用适当修饰表面特征的富勒烯在体外模型（包括我们已经建立的大鼠肺泡上皮细胞原代培养单层）和大鼠肺中，我们将通过研究以下四个目标来验证这些假设：1)在体外，顶部暴露富勒烯对肺泡上皮主动和被动屏障特性的影响；2)富勒烯在肺泡上皮细胞的内化、命运和作用；3)富勒烯在体外肺泡上皮内的转运；4)富勒烯在大鼠肺内的内化和运输，体内与体外对远端呼吸上皮的损伤和运输的相关性。本文提出的研究结果将有助于深入了解具有特定物理化学性质的富勒烯进入/穿过肺泡上皮的细胞毒性和内化/运输机制。我们的主要目标是获得富勒烯（和其他ENM）与肺泡上皮相互作用的新信息，以帮助理解与肺的相互作用，并帮助改善未来的纳米生物医学应用（例如，肺药物/基因传递）。

DESCRIPTION (provided by applicant): Although utilization of engineered nanomaterials (ENM) due to expansion of the science and application of nanobiomedicine/technology is expected to markedly increase, the mechanisms by which ENM injure and/or are transported into/across lung alveolar epithelium are not well known. Inhalation of ambient ultrafine particulates (whose size range overlaps the current definition of nanomaterials) has been shown to result in adverse cardiovascular, pulmonary and hematologic effects. If any ENM are accidently inhaled, their most likely route of entry into the systemic circulation is across the alveolar epithelium of the lung. Based on our ongoing research on lung injury and trafficking of several (e.g., polystyrene, silica and metal (oxides)) classes of nanoparticles with defined physicochemical characteristics, and recent reports on health effects of inhaled ultrafine air pollutant particulates and other nanomaterials (especially fullerenes and their derivatives), we hypothesize that interactions between various forms of ENM (e.g., negative vs. positive fullerenes; pristine (hydrophobic) vs. derivatized (hydrophilic) fullerenes; fullerenes of different mass (e.g., C60, C70, vs. C80 vs. polymeric fullerenes) and alveolar epithelial cells i) can disrupt normal alveolar epithelial cell homeostasis and induce changes in cellular properties and alveolar epithelial barrier function in an ENM-specific manner, ii) can provide the primary portal of entry for ENM into the systemic circulation (e.g., fullerenes may be translocated via transepithelial translocation pathways), and iii) are highly dependent on physicochemical properties of ENM (e.g., fullerenes). Utilizing fullerenes of appropriately modified surface characteristics in in vitro models (including our well-established primary cultured monolayers of rat alveolar epithelial cells) and rat lungs in vivo, we will test these hypotheses by investigating the following four aims: 1) effects of apically exposing fullerenes on active and passive barrier properties of alveolar epithelium in vitro; 2) internalization, fate and effects of fullerenes in alveolar epithelial cells in vitro; 3) trafficking of fullerenes across alveolar epithelium in vitro; and 4) fullerene internalization and trafficking in rat lungs in vivo, correlating injury to and trafficking across distal respiratory epithelium in vivo vs. in vitro. Findings from the investigations proposed herein will provide insights into cytotoxicity and mechanisms of internalization/trafficking of fullerenes with defined physicochemical properties into/across lung alveolar epithelium. Our major objective is to obtain new information on fullerene (and other ENM) interactions with alveolar epithelium in order to help understand interactions with the lung, and help improve future nanobiomedical applications (e.g., pulmonary drug/gene delivery). PUBLIC HEALTH RELEVANCE: Inhalation of man-made nanomaterials (<100 nm in diameter), including ultrafine ambient pollutant particles and engineered/manufactured nanomaterials (ENM: examples are fullerenes (composed of >60 carbon atoms), carbon nanotubes (CNT), quantum dots and metal /metal oxide nanoparticles), may be associated with various heart-, blood- and lung-related health effects. It appears that these effects may increase morbidity and mortality in susceptible populations. Of these nanomaterials, fullerenes have been manufactured in an astonishingly large quantity for wide applications, yet the mechanisms by which this particular ENM (e.g., fullerenes with positive vs. negative surface charges and/or pristine (lipid-loving) vs. derivatized (water-loving)) injure and/or are translocated into and/or across alveolar epithelium (where gas exchange and ion transport occur in the distal portion of the lung) are not well understood. We will determine interactions with both in vitro and in vivo rat models of the distal air-blood barrier of the lung (i.e., alveolar epithelium) in order to help understand possible injury from inhaled fullerenes with defined surface properties (e.g., charge and hydrophobicity). With this knowledge, improved nanomedical and biological applications (e.g., drug/gene delivery) using fullerenes bearing specific surface properties (that do not cause injury) can be designed for future applications.