NER: Triggering Nanovesicle Functions

国家科学基金会-活性纳米结构和纳米系统(ANN)(NSF05-610)纳米探索性研究(NER)摘要建议编号：CTS-0608827首席研究员：卡普兰，戴维德隶属：塔夫斯大学提案标题：NER：触发纳米囊泡功能智力价值近年来，一类新的生物多聚体两亲性化合物(乳胶复合脂杂多糖)被表征，其中可以通过对生物合成的生理和遗传操作来实现对结构特征(聚合物链长度、频率和成脂侧链的化学)的详细控制。此外，这些结构上的变化直接影响聚合物的溶液行为，包括乳化和表面张力特性。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“有效载荷”的天然能力，以及(B)形成微泡和纳米囊泡。NER的目标是对这些新型纳米微囊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轮廓。为了实现这一目标，我们计划：(1)了解聚合物两亲性结构与纳米微囊形态和稳定性之间的关系，以及(2)通过酶负载增强具有驱动功能的纳米微囊，以控制作为有效负载的多肽和蛋白质从纳米微囊中的释放动力学。根据结构变体的特定特征、加工中使用的共油以及形成结构的物理过程，聚合物双亲分子将形成结构和形态可控的纳米囊泡。将进行详细的结构和形态表征。随后，释放激活酶(对温度或pH敏感的脂肪酶可以激活/失活)将与选择性模型有效载荷化合物(牛血清白蛋白、枯草杆菌酶)一起加入到纳米胶囊中。脂肪酶激活纳米微囊的基础是去除乳胶的成脂脂肪酸侧链，从而否定与有效载荷的相互作用，导致释放。酶激活剂的活性将由外部因素(pH、温度)“触发”。这一努力的结果将是从根本上理解生物多聚体双亲分子的结构和功能之间的关系，这些关系与载体分子的被动和主动释放动力学有关。这一洞察力将对未来利用释放功能的系统设计至关重要，例如用于活化表面涂层、农业和药物成分的受控释放、自修复聚合物复合材料和许多相关应用。该项目将为研究生和本科生在一年NER计划中的跨学科学生体验提供肥沃的土壤。将重点关注工程学和生物学交叉的主题，这些主题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方面具有强烈的影响。将根据NER计划开发一个教学模块，供塔夫茨大学内部课程(本科生和研究生)使用，并由学生提供投入和准备，并通过工程教育外联中心进行外部传播，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、普通材料科学和工程系统等领域具有广泛的影响。例如，由于对这类生物聚合物的结构和功能进行了广泛的控制，这些系统的适用性可能很广泛。此外，用于合成生物聚合物的绿色化学和体系在完成释放功能后的降解性提供了生物/环境相容性的完整循环。由于生物聚合物也是生物相容的，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.