CAREER: Nanoparticle-Bacterial Membrane Interactions and their Role in Nanotoxicology

职业：纳米颗粒-细菌膜相互作用及其在纳米毒理学中的作用

• 批准号: 1055652
• 负责人: Geoffrey Bothun
• 金额: $ 40万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-15 至 2018-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1055652&HistoricalAwards=false
• 关键词: CAREER; Nanoparticle; Bacterial; Membrane; Interactions

Cellular responses ultimately determine the toxicological impacts of nanoparticles released intentionally or unintentionally into the environment. Physical nanoparticle-cell membrane interactions are emerging as an important factor in determining cell uptake and cytotoxicity as membranes are the point-of-contact for nanoparticle-cell interactions and membranes integrity is vital to cell function. However, these interactions are poorly understood and have not been examined in or connected to biomimetic membranes that exhibit heterogeneity or asymmetry. The research objective of this CAREER proposal is to elucidate nanoparticle-membrane interactions in model bacterial membranes as a function of nanoparticle size and surface chemistry, and salt concentration. AIM 1 will employ cryogenic microscopy and microcalorimetry examine how local nanoparticle-membrane interactions can yield global changes in membrane structure and function. AIM 2 will employ microscopy and spectroscopy techniques to specifically examine the role of nanoparticle aggregation at membrane/water interfaces and its effects on inducing membrane invagination (i.e. engulfing nanoparticles) and poration. Finally, AIM 3 will employ the aforementioned experimental techniques to examine polysaccharide (dextran)-coated vesicles as model cell wall/membrane barriers to link underlying nanoparticle-membrane interactions with a realistic composite membrane. The CAREER plan of the PI integrates research with the educational and outreach objective of engaging underrepresented students and local communities, enhancing career preparedness in emerging technologies, specifically at the nanotechnology/environmental/biological interface, and advancing curriculum. Building on the PI?s previous experiences, a new high school program Think Small/Dream Big! will be developed for science classes in urban schools in the greater Providence, RI area. This program will leverage the remote operating capabilities of the recently awarded NSF MRI-funded transmission electron microscope and provide students ?virtual? exposure to analyzing nanomaterials using state-of-the-art instrumentation. This proposal will also enhance a new freshman general education course at URI aimed at educating students about the social, economic, and environmental impacts of nanotechnology, as well as the need to effectively communicate emerging technologies to broad audiences. Professional development activities, including research and specialized workshops, will supplement curriculum development and provide enhanced ?soft? and technical skills needed for research careers and graduate studies. Taken together, the research and education plans will support the independent career path of the PI as a successful scholar and educator. Intellectual Merit. Research is driven by the hypotheses that (1) an ?optimal? combination of size and surface chemistry exists to facilitate nanoparticle-membrane binding and membrane restructuring, which is balanced by the net adhesive strength and energetic penalty for distorting a membrane; (2) nanoparticle aggregation at membrane/water interfaces leads to size-dependent membrane pore formation and nanoparticle invagination; and that (3) polysaccharide-coatings mimicking cell walls will reduce, but not eliminate nanoparticle-induced membrane restructuring. Quantitative information, which is currently lacking, relating to the degree of nanoparticle binding, how this affects membrane structure, phase behavior, and permeability will be gained for environmentally-relevant bacterial membranes. This work is transformative because nanoparticle-membrane interactions and the role of the cell wall have not been examined for bacterial membrane. Broader Impacts. A quantitative understanding of nanoparticle-membrane interactions will provide new insight into cytotoxicity mechanisms, and could help develop general guidelines for predicting nanoparticle-cell association and designing biocompatible nanomaterials. Beyond cytotoxicity, this understanding could be used to create or modify nanoparticle-based therapeutics, design hybrid organicinorganic colloids, and identify new biosensing or drug delivery strategies. Dissemination will be achieved through publications, presentations, and integration into courses and outreach activities. The crux of this proposal is that the research concepts can be used as educational and outreach material to inspire underrepresented students to achieve STEM careers, engage and inform community organizations

细胞反应最终确定故意或无意间释放到环境的纳米颗粒的毒理学影响。物理纳米颗粒细胞膜相互作用是确定细胞摄取和细胞毒性的重要因素，因为膜是纳米粒子 - 细胞相互作用的接触点，而膜完整性对细胞功能至关重要。然而，这些相互作用的理解很少，尚未在表现出异质性或不对称性的仿生膜中进行检查或连接。该职业建议的研究目标是阐明模型细菌膜中的纳米颗粒 - 膜相互作用，这是纳米颗粒大小和表面化学和盐浓度的函数。 AIM 1将采用低温显微镜和微量钙化法检查局部纳米颗粒 - 膜相互作用如何产生膜结构和功能的全球变化。 AIM 2将采用显微镜和光谱技术来专门检查纳米颗粒聚集在膜/水接口上的作用及其对诱导膜内侵蚀（即吞噬纳米颗粒）和孔隙的影响。最后，AIM 3将采用上述实验技术来检查多糖（Dextran）涂层囊泡作为模型细胞壁/膜屏障，以将纳米颗粒 - 膜膜相互作用与现实复合膜相互作用。 PI的职业计划将研究与教育和外展的目标相结合，该目标是吸引代表性不足的学生和当地社区，增强新兴技术的职业准备，特别是在纳米技术/环境/生物学界面，并推进课程。在Pi的先前经验的基础上，一个新的高中计划认为小/梦想！将为RI大普罗维登斯市的城市学校的科学课程开发。该计划将利用最近授予的NSF MRI资助的传输电子显微镜的远程操作能力，并为学生提供虚拟？使用最先进的仪器暴露于分析纳米材料。该建议还将在URI上加强新的新生通识教育课程，旨在向学生介绍纳米技术的社会，经济和环境影响，以及有必要有效地将新兴技术传达给广泛的受众。包括研究和专业研讨会在内的专业发展活动将补充课程开发并提供增强？研究职业和研究生学习所需的技术技能。综上所述，研究和教育计划将支持PI作为成功的学者和教育者的独立职业道路。智力优点。研究是由（1）最佳的假设驱动的？存在大小和表面化学的结合，以促进纳米颗粒 - 膜结合和膜重组，这通过净粘合强度和扭曲膜的净粘合强度和能量惩罚平衡； （2）膜/水接口处的纳米颗粒聚集会导致尺寸依赖性膜孔的形成和纳米颗粒的内陷； （3）模仿细胞壁的多糖涂料将减少，但不能消除纳米颗粒诱导的膜重组。目前缺乏与纳米颗粒结合程度有关的定量信息，这将如何影响与环境相关的细菌膜的膜结构，相行为和渗透率。这项工作具有变革性，因为尚未检查细菌膜的纳米颗粒 - 膜相互作用和细胞壁的作用。更广泛的影响。对纳米颗粒 - 膜相互作用的定量理解将为细胞毒性机制提供新的见解，并可以帮助制定预测纳米颗粒细胞关联并设计生物相容性纳米材料的一般指南。除了细胞毒性之外，这种理解可用于创建或修改基于纳米颗粒的治疗疗法，设计混合有机有机胶体，并确定新的生物传感或药物输送策略。传播将通过出版物，演讲以及将课程和外展活动的融合融合来实现。该提案的症结在于，研究概念可以用作教育和外展材料，以激发代表性不足的学生来实现STEM职业，参与和告知社区组织