Thermodynamics and Chain Dynamics in Spin-labeled Peptide Block Copolymer Assemblies

化学系的大分子、超分子和纳米化学项目获得这一奖项，资助佛罗里达大学化学系的Daniel A.Savin教授和Gail E.Fanucci教授探索自旋标记的含肽嵌段聚合物的自组装，以发现分子结构和相互作用如何导致全球形态变化。鉴于多肽化学家拥有丰富的蛋白质结构、折叠和功能方面的知识，聚合物科学家可以使用这个工具箱，并将同样的原理应用于合成聚合物-多肽杂交系统。从应用的角度来看，基于多肽的杂化材料已经显示出作为pH敏感的药物载体和水凝胶的潜力，在生物相容性方面具有优势。响应性材料也被用来制造分子致动器和可切换表面。Savin和Fanucci小组的培训计划整合了从K-12到博士后研究人员的广泛学科的教学和研究，包括化学、物理、生物化学和聚合物科学。学生将全面了解聚合物和生物材料在合成、表征、形态、光谱、散射和流变学等多个领域的知识。这种多学科的方法不仅从教育的角度来看是必不可少的，而且对于培养出全面发展的毕业生来说也是至关重要的，这些毕业生对学术界和工业界的各种雇主都有吸引力。该团队致力于扩大参与，并强烈鼓励本科生参与研究。外展计划延续了Savin和Fanucci分别在K-5和9-12级别上非常成功的两个计划，并增加了一个旨在指导当地寄养儿童的高中水平的新计划。这项研究的重点是利用特定位置的自旋标记作为探针来表征局部环境，并监测基于多肽的嵌段共聚物组装中自组装和形态转变的变化。制备了含有自由基自旋标记剂TEMPO和氨基乙基哌嗪的大分子引发剂。然后，通过氨基酸的N-羧酸酐开环合成了共聚物。光谱工具，如电子顺磁共振和Overhauser动态核极化核磁共振波谱，用于提供响应性嵌段共聚物组件的端到端分布、水化、可及性和链段动力学的本地询问。这种表征与形态表征相结合，使用光散射和电子显微镜来确定关键参数，如尺寸、形状、聚集数和组装体界面的平均链密度。与这项研究相关的结果可以建立一个新的分析平台，以确定组装中聚合物的局部构象、热力学和动态性质。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。

With this award, the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry is funding Professors Daniel A. Savin and Gail E. Fanucci of the Department of Chemistry at University of Florida to explore the self-assembly of spin-labeled, peptide containing block polymers to discover how molecular level structure and interactions can result in global morphology changes. Given the wealth of knowledge that peptide chemists have regarding protein structure, folding, and function, polymer scientists can use this toolbox and apply the same principles to synthetic polymer-polypeptide hybrid systems. From an application standpoint, peptide-based hybrid materials have shown potential as pH sensitive drug delivery vehicles and hydrogels that have advantages in terms ofbiocompatibility. Responsive materials have also been used to produce molecular actuators and switchable surfaces. The training program in the Savin and Fanucci groups integrates teaching and research in a broad range of disciplines including chemistry, physics, biochemistry and polymer science, from K-12 to postdoctoral researchers. Students gain a comprehensive understanding of polymers andbiomaterials in many areas of synthesis, characterization, morphology, spectroscopy, scattering and rheology. This multidisciplinary approach is essential not only from an educational standpoint, but also to produce well-rounded graduates who are attractive to a variety of employers in both academic and industrial settings. The team is committed to broadening participation and strongly encourages research participation by undergraduates. The outreach program continues two highly successful programs by Savin and Fanucci at the K-5 and 9-12 levels, respectively, and adds a new program aimed at mentoring local foster children at the high school level. This research is focused on utilizing site specific spin-labels as probes to characterize the local environment and monitor changes in the self-assembly and morphological transitions in peptide-based block copolymer assemblies. Macroinitiators are prepared that contain the radical spin label agent TEMPO, and aminoethylpiperazine. Copolymers are then synthesized by ring opening of N-carboxyanhydrides of amino acids. Spectroscopic tools such as electron paramagnetic resonance and Overhauser dynamic nuclear polarization NMR spectroscopy are used to provide local interrogation of end-to-end distributions, hydration, accessibility, and segmental dynamics in responsive block copolymer assemblies. This characterization is coupled with morphology characterization where light scattering and electron microscopy are used to determine critical parameters such as size, shape, aggregation number, and the average chain density at the interface of the assemblies. Results associated with this research could enable the establishment of a new analytical platform to determine local conformational, thermodynamic, and dynamic properties of polymers in assemblies.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.