Collaborative Research: Rational Design and Mechanistic Understanding of Carbon-Based Hybrid Nanostructures for Potent Microbicidal Function

非技术摘要：细菌病原体的感染，特别是那些对抗生素具有抗药性的病原体感染，是对该国公共健康的主要威胁，每年有数百万人受到感染，并有相当数量的人死亡。因此，迫切需要其他方法来防止这种感染的传播。基于纳米材料的方法有望成为对抗多药耐药(MDR)细菌的抗菌剂。这一合作项目将开发和建立新发现的光活性纳米材料，特别是碳点(CDot)和衍生的“混合点”(与其他成分一起)，作为杀死耐多药细菌的独特有效的生物材料平台。CDot是一种核壳结构，每个CDot都有一个纳米级的碳颗粒作为核心，有机分子作为其表面(壳)的涂层。当CDot暴露在对人类友好的可见光/自然光或环境光下时，它们会产生对细菌病原体高度致命的类似自由基的物种，使其成为抗菌应用的优秀生物纳米材料。本项目将利用一些新的策略设计CDot和杂交点，以改善和优化抗菌性能，预计将对控制MDR病原体产生广泛的积极影响，并对学生在重要生物材料领域的培训产生积极影响。技术摘要：本合作项目旨在进一步开发和建立碳点(CDot)及其衍生的杂化纳米结构，作为一种独特的生物材料平台，用于可见光/自然或环境光激活的强大的抗菌功能。CDot可以被认为是一种特殊的核壳杂化纳米结构，每种结构都有一个小的碳纳米颗粒核心和一层用于颗粒表面钝化的附着有机材料的薄壳。它们在可见光光谱中具有很强的吸收能力，它们的光激发态特性和过程类似于半导体量子点中的典型特性，但具有独特的优势。用有机部分修饰斑点表面的多功能性和灵活性使CDot的操作能够增强它们的光学性质以及它们与目标细菌细胞的相互作用。项目团队将利用这些独特的特性来设计和制备CDot及其衍生的杂化纳米结构，以获得所需的特性，其基本原理包括：1)更有效地获取整个可见光谱中的光子，2)负责抗菌活动的高效光激发态过程，以及3)更有针对性和更强的与细菌细胞的相互作用，从而建立CDot/杂交点作为有效和高效的广谱杀灭多重耐药病原体的试剂。这些努力将与对这些生物纳米材料的机理理解的调查相结合。该项目还将在社会效益和技术发展、机构研究的加强、本科生的教育和参与研究以及外展活动等方面产生更广泛的影响。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。

NON-TECHNICAL SUMMARY:Infections by bacterial pathogens, especially those that are resistant to antibiotics, represent a major threat to the public health in this country, with millions of people suffering from the infections and a significant number of deaths each year. Thus, there are urgent demands for alternative approaches to prevent the spread of such infections. Nanomaterials-based approaches hold promise to serve as antibacterial agents against multidrug-resistant (MDR) bacteria. This collaborative project will develop and establish the newly discovered photoactive nanomaterials, specifically carbon dots (CDots) and derived “hybrid dots” (with other components), as a uniquely potent biomaterials platform for killing MDR bacteria. CDots are of a core-shell structure, each with a nanoscale carbon particle as the core and organic molecules as the coating on its surface (shell). When exposed to human-friendly visible/natural or ambient light, CDots generate radical-like species that are highly lethal to bacterial pathogens, making them excellent bio-nanomaterials for antibacterial applications. This project will use some new strategies to design CDots and hybrid dots to improve and optimize the antibacterial performance, with expected broad positive impacts to the control of MDR pathogens, and also to the training of students in the important biomaterials field.TECHNICAL SUMMARY:This collaborative project is to further develop and establish carbon dots (CDots) and derived hybrid nanostructures as a unique biomaterials platform for visible/natural or ambient light-activated potent antibacterial function. CDots may be considered as a special kind of “core-shell” hybrid nanostructures, each with a small carbon nanoparticle core and a thin shell of attached organic materials for the particle surface passivation. They are strongly absorptive in the visible spectrum, and their photoexcited state properties and processes resemble those typically found in semiconductor quantum dots, but with unique advantages. The versatility and flexibility of modifying the dot surface with organic moieties enable the manipulation of CDots to enhance their optical properties and their interactions with the targeted bacterial cells. The project team will leverage these distinctive characteristics to design and prepare CDots and derived hybrid nanostructures for the desired properties based on the rationales including 1) the more effective photon harvesting across the entire visible spectrum, 2) highly efficient photoexcited state processes responsible for the antimicrobial activities, and 3) more targeted and stronger interactions with the bacterial cells, thus to establish the CDots/hybrid dots as effective and efficient broad spectrum agents for killing multidrug-resistant pathogens. The efforts will be coupled with investigations for mechanistic understanding of these bio-nanomaterials. The project will also have broader impacts in terms of societal benefits and technology development, institutional research enhancement, education and engagement of undergraduate students in research, and outreach activities.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.