New mechanisms for controlled polymer degradation and their incorporation into functional three-dimensional materials

受控聚合物降解的新机制及其融入功能性三维材料

• 批准号: RGPIN-2016-04636
• 负责人: Gillies, Elizabeth
• 金额: $ 5.46万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691902
• 关键词: New; mechanisms; controlled; polymer; degradation

Polymers that undergo degradation to small molecules in the environment or in the human body are of significant interest to both academia and industry for a wide range of applications from packaging to medical devices. Ideally, a polymer would be highly stable while performing its function, but would break down rapidly under the desired conditions. Currently available materials typically undergo degradation by random backbone scission and degrade gradually in a wide range of environments, limiting our ability to trigger and control this degradation. The proposed research program aims to develop a class of polymers that degrade specifically by an end-to-end depolymerization mechanism in response to the cleavage of a stimuli-responsive end-cap from the polymer terminus. New end-caps responsive to different stimuli such as changes in the concentrations of oxidizing or reducing species, heat, light and even multiple combinations of such stimuli will be developed, enhancing our understanding of their degradation behavior and demonstrating the potential to tune these polymers for a variety of applications. Through careful design of these end-caps, polymers composed of multiple blocks will also be prepared. The incorporation of new monomers will enable the properties of the polymers to be tuned, further chemical derivatization to be performed, and for new functions such as drug incorporation to be introduced. *** The ultimate functions of these new depolymerizable molecules will be realized through their incorporation into 3-dimensional materials. Block copolymers will be incorporated into nanometer-sized assemblies including micelles and vesicles, which will be explored for their ability to encapsulate and release cargo such as anti-cancer drugs, therapeutic nucleic acids, and growth factors for tissue engineering in a controlled manner. The polymers will also be used to fabricate porous scaffolds for the growth of cells for tissue engineering. The ability to change the stimuli to which the polymers respond, simply by changing the end-cap, will offer a significant advantage over the current polymers in terms of our ability to prepare and study a wide range of new materials responsive to different stimuli. Furthermore, the ability to degrade an entire polymer chain following a single stimulus-mediated event can provide a significant amplification of the stimulus, enabling changes in material properties to occur at low, cell-compatible stimulus concentrations. Overall, this research will enable transformative advancements in our understanding of stimuli-responsive materials while at the same time affording new properties and functions for the target applications. **

从包装到医疗设备的广泛应用，学术界和工业都非常感兴趣地对环境或人体中的小分子降解的聚合物引起了人们的重大关注。理想情况下，在执行其功能时，聚合物将是高度稳定的，但是在所需条件下会迅速分解。当前可用的材料通常会通过随机的主链分裂而经历降解，并在各种环境中逐渐降解，从而限制了我们触发和控制这种降解的能力。拟议的研究计划旨在开发一类聚合物，这些聚合物因响应于聚合物末端的刺激反应性终端cap的裂解而专门通过端到端解聚机制降低。将开发出对不同刺激的响应的新末端盖子，例如将开发氧化或减少物种的浓度，热，光甚至多种组合的变化，从而增强我们对它们降解行为的理解，并证明有可能调整这些聚合物以获得这些聚合物以获得这些聚合物以获得这些聚合物多种应用。通过仔细设计这些端盖，还将准备由多个块组成的聚合物。新单体的掺入将使聚合物的性质进行调节，进一步进行化学衍生化，并用于引入新功能（例如药物掺入）。 ***这些新的可聚合分子的最终功能将通过将其掺入三维材料中实现。块共聚物将掺入包括胶束和囊泡在内的纳米大小的组件中，这些组件将因其封装和释放货物的能力，例如抗癌药物，治疗核酸，以及以受控方式进行组织工程的生长因子。聚合物还将用于制造多孔脚手架，以用于组织工程的细胞生长。就我们准备和研究对不同刺激响应的广泛的新材料而言，更改聚合物响应的刺激的能力将与当前聚合物相比具有显着优势。此外，在单个刺激介导的事件之后降解整个聚合物链的能力可以对刺激进行显着扩增，从而使材料特性的变化在低细胞兼容的刺激浓度下发生。总体而言，这项研究将在我们对刺激响应材料的理解中实现变革性的进步，同时为目标应用提供新的属性和功能。 **