Biomolecular Mechanisms of Interaction between 2D Chalcogenide Materials and Environmentally-Relevant Biosystems

二维材料由原子薄层组成，具有确定的晶体结构和较大的横向尺寸。这个项目的重点是二维过渡金属二卤化物。这些材料是在过去的十年里出现的，因为它们独特的光电性质，适合在现代计算、生物传感和通信以及物联网中广泛应用。尽管这些二维材料在负担得起的技术上有希望，但人们对它们在与环境相关的生物系统界面上的行为知之甚少。该项目将研究二维纳米材料与哺乳动物细胞相互作用的行为，重点放在三个不同的方面：细胞摄取的机制；纳米材料在哺乳动物细胞中的潜在结构转变；以及细胞环境中的反应性，特别是了解任何潜在的炎症效应。这一项目的成果将通过同行评议的出版物和会议发言广泛传播。在使用纳米材料时，环境管理是至关重要的，该项目将通过提供数据来指导新材料的监管，从而使社会受益。佛罗里达国际大学是一所西班牙裔服务机构，学生群体非常多样化，该项目将吸引来自少数族裔群体的学生进入科学和工程领域。本科生和研究生将学习材料科学和工程、生物和环境科学，走向科学和工程教育的融合。该项目的总体目标是揭示具有潜在应用于与环境相关的生物系统的二维过渡金属二卤化物之间的基本相互作用模式。将重点放在原始形式的材料(非功能化)上，将有助于评估在材料加工和搬运过程中预期的主要暴露类型。选择了适用于未来技术的具有代表性的过渡金属二卤化物材料：电子应用的主要成分二硫化钼和潜在的光声治疗试剂二硫化钛。将通过研究材料与人皮肤成纤维细胞的相互作用以及与A549肺癌细胞的吸入来模拟皮肤暴露。此外，对于这些材料，所有已知的合成方法都赋予了不同的尺寸和表面性质，这是合成路线所固有的，包括配体、缺陷和吸附物种。二维过渡金属二卤化物也表现出多型性，这种多型性可能会在细胞环境中发生变化。研究人员假设过渡金属二卤化物的性质与某些现象密切相关：i)。物理相互作用，涉及细胞摄取的机制；ii)。体外相变，指细胞中的物质相变；以及iii)。化学作用，可能发生在材料与细胞环境的交界处。选定的两种材料二硫化钼和二硫化钛将通过所有已知的二维过渡金属二卤化物合成方法合成，并以原始形式分别与肺癌细胞和皮肤细胞相互作用。该项目有以下目标：建立二维过渡金属二盐化合物纳米片的合成方法与其原始形式的细胞摄取之间的关系；通过原位拉曼光谱阐明二维过渡金属二盐化合物多型在细胞环境中的结构变化；以及建立二维过渡金属二盐化合物性质与活细胞中潜在炎症效应之间的关系。该项目将有助于全面了解二维过渡金属二卤化物在选定细胞中的进入机制，细胞环境对多型性的潜在影响，以及暴露的细胞作为纳米片表面化学的功能的潜在炎症反应。佛罗里达国际大学是一所西班牙裔服务机构，学生群体非常多样化，该项目将吸引来自少数族裔群体的学生进入科学和工程领域。本科生和研究生将致力于学习材料科学和工程、生物和环境科学，以实现科学和工程教育的融合。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Two-dimensional materials consist of atomically thin layers with defined crystal structure and large lateral dimensions. This project focuses on two-dimensional transition metal dichalcogenides. These materials emerged in the past decade due to their unique optoelectronic properties, which are suitable for a wide range of applications in modern computing, biosensing, and communications, and the Internet of Things. Although these 2-dimensional materials have promise in affordable technologies, very little is known concerning their behavior at the interface with environmentally-relevant biological systems. This project will investigate the behavior of two-dimensional nanomaterials interacting with mammalian cells, focusing on three distinct aspects: the mechanism of cellular uptake; the potential structural transformations of the nanomaterial in the mammalian cells; and the reactivity in the cellular environment, especially to understand any potential inflammatory effects. The results of this project will be widely disseminated through peer-reviewed publications and conference presentations. Environmental stewardship is critical when using nanomaterials and the project will benefit society by providing data to guide regulation of new materials. Florida International University is a Hispanic Serving Institution with a very diverse student population and this project will engage students from underrepresented minority groups in science and engineering. Undergraduate and graduate students will be engaged in learning materials science and engineering, biology and environmental science, toward a convergent science and engineering education.The overarching goal of this project is to uncover fundamental modes of interaction between two-dimensional transition metal dichalcogenides that have potential applications for environmentally-relevant biological systems. Focusing on materials in their pristine form (non-functionalized) will facilitate assessment of the primary type of exposure expected during processing and handling of materials. Representative transition metal dichalcogenide materials applicable for future technologies were selected: molybdenum disulfide, a major component of electronic applications, and titanium disulfide, a potential photoacoustic therapeutic reagent. Skin exposure will be simulated by studying the materials interaction with Human Skin Fibroblast cells, and inhalation with A549 lung cancer cells. In addition, for these materials all of the known synthetic methods confer variable size and surface properties, intrinsic to the synthetic route, including ligands, defects, and adsorbed species. 2-dimensional transition metal dichalcogenides also exhibit polytypism which might be altered in the cellular environment. The investigator hypothesizes that the properties of the transition metal dichalcogenides are strongly correlated with certain phenomena: i). Physical interactions, involving the mechanism of cellular uptake; ii). In vitro phase transformations, referring to material phase changes in the cell; and iii). Chemical interactions, that could occur at the interface of the material with the cellular environment. The two selected materials, molybdenum disulfide and titanium disulfide, will be synthesized through all known 2-dimensional transition metal dichalcogenide synthetic methods and used in their pristine form to interact with lung cancer cells and skin cells, respectively. The project has the following objectives: establish the correlation between the synthetic method of the 2-dimensional transition metal dichalcogenide nanosheets and their cellular uptake in pristine form; elucidate the structural transformations of 2-dimensional transition metal dichalcogenide polytypes within the cellular environment by in situ Raman spectroscopy; and establish the correlation between 2-dimensional transition metal dichalcogenide properties and potential inflammatory effects in living cells. This project will contribute to a general understanding of the 2-dimensional transition metal dichalcogenide entry mechanism in the selected cells, the potential impacts of cellular environment on polytypes, and the potential inflammatory responses of exposed cells, as a function of nanosheet surface chemistry. Florida International University is a Hispanic Serving Institution with a very diverse student population and this project will engage students from underrepresented minority groups in science and engineering. Undergraduate and graduate students will be engaged in learning materials science and engineering, biology and environmental science, toward a convergent science and engineering education.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.