NER: Triggering Nanovesicle Functions

美国国家科学基金会-活性纳米结构和纳米系统（ANN） （NSF 05-610）纳米尺度探索性研究（NER）摘要提案号：CTS-0608827首席研究员：Kaplan， david隶属机构：Tufts大学提案标题：NER；近年来，一类新的生物聚合物两亲体（乳剂复合脂杂多糖）已经被表征，通过生物合成的生理和遗传操作可以获得详细的结构特征控制（聚合物链长度、频率和脂质侧链的化学性质）。此外，这些结构的变化直接影响聚合物的溶液行为，包括乳化和表面张力性能。在最近的研究中，我们将这些系统扩展到：(a)模拟这些复杂聚合物携带其他分子（蛋白质）的天然能力，以及(b)形成微和纳米囊泡。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)了解聚合物两亲结构与纳米囊泡形态和稳定性之间的关系；(2)通过酶有效载荷增强纳米囊泡的驱动功能，以控制肽和蛋白质作为有效载荷从纳米囊泡释放动力学。根据结构变体的具体特征、加工中使用的共油以及形成结构的物理过程，聚合物两亲体将形成具有结构和形态控制的纳米微泡。将进行详细的结构和形态表征。随后，将释放激活酶（具有温度或pH敏感性的脂肪酶激活/失活）与选择性模型有效载荷化合物（牛血清白蛋白，枯草菌素酶）一起纳入纳米囊泡。脂肪酶驱动纳米囊泡将基于去除乳化剂的脂源脂肪酸侧链，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”。这项工作的结果将是对生物聚合物两亲体结构和与携带分子的被动和主动释放动力学相关的功能之间关系的基本理解。这一见解将对未来开发释放特性的系统设计至关重要，例如用于活化表面涂层、农业和药理学内容物的可控释放、自修复聚合物复合材料和许多相关应用。该项目将在一年的NER项目中为研究生和本科生提供跨学科体验的肥沃土壤。将重点关注工程与生物学的交叉领域，这些领域在药物释放控制、具有活化功能的表面涂层和许多相关主题方面具有重要意义。将根据NER计划开发一个教学模块，用于塔夫茨大学的内部课程（本科和研究生水平），由学生投入和准备，并通过工程教育推广中心进行外部传播，作为K- 12教育更广泛传播工作的一部分。从技术上讲，拟议的研究在环境，医学和一般材料科学和工程系统领域具有广泛的意义。例如，由于对该生物聚合物家族的结构和功能进行了广泛的控制，这些系统的适用性可能是广泛的。此外，用于合成生物聚合物的绿色化学和系统在完成释放功能后的可降解性提供了一个完整的生物/环境相容性循环。由于生物聚合物也具有生物相容性，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.