NER: Triggering Nanovesicle Functions

美国国家科学基金会-主动纳米结构和纳米系统（ANN）（NSF 05-610）纳米尺度探索性研究（NER）摘要提案编号：CTS-0608827主要研究者：Kaplan，David所属机构： 塔夫茨大学提案标题：NER：触发纳米囊泡功能智力优点近年来，生物聚合物两亲物（emulsans复合脂杂多糖）的一个新家族已经被表征，其中可以通过生物合成的生理和遗传操纵来实现对结构特征（聚合物链长度、频率和脂肪生成侧链的化学）的详细控制。此外，这些结构变化直接影响聚合物的溶液行为，包括乳化和表面张力性质。 在最近的研究中，我们已经将这些系统扩展到：（a）模拟这些复杂聚合物携带其他分子（蛋白质）的“有效载荷”的天然能力，以及（B）形成微米和纳米囊泡。NER的目标是对这些新型纳米囊泡载体系统的结构和功能的控制有一个基本的了解，并结合触发功能来调节所携带的有效载荷的释放曲线。为了实现这一目标，我们计划：（1）了解聚合物两亲物结构与纳米囊泡形态和稳定性之间的关系，以及（2）通过酶有效载荷增强具有驱动功能的纳米囊泡，以控制作为有效载荷的肽和蛋白质从纳米囊泡的释放动力学。聚合物两亲物将形成纳米泡，其中基于结构变体的具体特征、加工中使用的共油和用于形成结构的物理过程来控制结构和形态。 将进行详细的结构和形态表征。随后，将释放活化酶（具有温度或pH敏感性以活化/失活的脂肪酶）与选择性模型有效载荷化合物（牛血清白蛋白、枯草杆菌蛋白酶）一起沿着掺入纳米囊泡中。纳米囊泡的脂肪酶酶致动将基于emulsan的产脂脂肪酸侧链的去除，从而消除与有效载荷的相互作用，导致释放。酶致动器的活性将由外部因素（pH、温度）“触发”。这一努力的结果将是一个基本的理解生物聚合物的两亲结构和功能之间的关系，有关的被动和主动释放动力学的分子。这一见解将是至关重要的系统的未来设计，利用释放功能，如活化表面涂层，农业和药理学内容的控制释放，自修复聚合物复合材料和许多相关的应用。更广泛的影响该项目将提供肥沃的土壤跨学科的学生在研究生和本科生在一年的NER计划的经验。重点关注工程和生物学之间的交叉点，在药物输送的控制释放，具有可激活功能的表面涂层和许多相关主题领域具有强烈的影响。一个教学模块将开发基于NER计划用于内部课程（本科和研究生水平）在塔夫茨，由学生输入和准备，以及通过工程教育外展中心的外部传播计划作为K- 12教育更广泛的传播工作的一部分。从技术上讲，拟议的研究在环境，医学和通用材料科学和工程系统领域具有广泛的影响。例如，这些系统的适用性是潜在的广泛的，由于广泛的控制结构，因此功能的这个家庭的生物聚合物。此外，用于合成生物聚合物的绿色化学和完成释放功能后系统的降解性提供了完整的生物/环境相容性循环。由于生物聚合物也是生物相容的，因此也可以考虑在体内使用的其他选择。

National Science Foundation - Active Nanostructure and Nanosystems (ANN) (NSF 05-610)Nanoscale Exploratory Research (NER)ABSTRACTProposal Number: CTS-0608827 Principal Investigator: Kaplan, DavidAffiliation: Tufts University Proposal Title: NER: Triggering Nanocesicle Functions Intellectual Merit A novel family of biopolymeric amphiphiles (emulsans complex lipoheteropolysaccharides) has been characterized in recent years in which detailed control of structural features (polymer chain length, frequency and chemistry of the lipogenic side chains) can be attained via physiological and genetic manipulation of the biosynthesis. Furthermore, these changes in structure directly impact solution behavior of the polymers, including emulsification and surface tension properties. In recent studies, we have extended these systems to: (a) mimic the native ability of these complex polymers to carry a 'payload' of other molecules (proteins), and (b) form micro and nano-vesicles. The goal of the NER is to develop a fundamental understanding of the control of structure and function of these novel nanovesicle carrier systems and incorporate triggering functions to regulate the release profiles of the payload being carried. To accomplish this goal, we plan to: (1) develop an understanding of the relationships between polymeric amphiphile structure and nanovesicle morphology and stability, and (2) enhance the nanovesicles with actuation functions via enzyme payloads to control the release kinetics of peptides and proteins as payloads from the nanovesicles. The polymer amphilphiles will be formed into nanovasicles with control of structure and morphology based on the specific features of the structural variant, the co-oils used in processing, and the physical process used to form the structures. Detailed structural and morphological characterization will be conducted. Subsequently, a release activating enzyme (lipases with temperature or pH sensitivities to activate/deactivate) will be incorporated into the nanovesicles along with selective model payload compounds (bovine serum albumin, subtilisin enzyme). Lipase enzyme actuation of the nanovesicles will be based on removal of the lipogenic fatty acid side chains of the emulsan, thus negating the interactions with the payload, resulting in release. The activities of the enzyme actuators will be 'triggered' from external factors (pH, temperature). The outcome of this effort will be a fundamental understanding of the relationships between biopolymeric amphilphile structure and function related to passive and active release kinetics of carried molecules. This insight will be critical to future designs of systems to exploit release features, such as for activated surface coatings, controlled release of agriculture and pharmacological contents, self-repairing polymer composites and many related applications.Broader Impact The project will provide fertile ground for interdisciplinary student experiences at both the graduate and undergraduate during one year NER Program. A focus on topics at the intersection between engineering and biology with strong implications in areas of controlled release in drug delivery, surface coatings with activatable functions and many related themes will be stressed. A teaching module will be developed based on the NER program for use in internal courses (undergraduate and graduate level) at Tufts, with input and preparation by the students, as well as for external dissemination via the Center for Engineering Education Outreach are planned as part of the broader dissemination effort for K- 12 education. Technically, the proposed studies have broad implications in areas of environmental, medical and general materials science and engineering systems. For example, the applicability of these systems is potentially broad due to the extensive control of structures and thus functions of this family of biopolymers. In addition the green chemistry used to synthesize the biopolymers and the degradability of the systems upon completion of release functions provides a complete cycle of bio/environmental compatablity. Since the biopolymers are also biocompatible, additional options for utility in vivo can also be considered.