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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708430
• 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.

在环境或人体内降解为小分子的聚合物在从包装到医疗设备的广泛应用中引起了学术界和工业界的极大兴趣。理想情况下，聚合物在执行其功能时高度稳定，但在所需条件下会迅速分解。目前可用的材料通常通过随机的骨架断裂进行降解，并在广泛的环境中逐渐降解，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特定地通过端到端解聚机制来降解的聚合物，以响应来自聚合物末端的刺激响应端帽的裂解。新的端盖将被开发出来，以响应不同的刺激，如氧化或还原物种浓度的变化，热，光，甚至这些刺激的多种组合，加强我们对它们的降解行为的了解，并展示调整这些聚合物用于各种应用的潜力。通过精心设计这些端盖，还将制备由多个嵌段组成的聚合物。新单体的加入将使聚合物的性质得到调整，进一步的化学衍生化，并引入新的功能，如药物掺入。 这些新的可解聚分子的最终功能将通过将它们结合到三维材料中来实现。嵌段共聚物将被纳入包括胶束和囊泡在内的纳米级组件中，以研究其以受控方式包裹和释放抗癌药物、治疗性核酸和组织工程生长因子等货物的能力。这种聚合物还将用于制造组织工程细胞生长的多孔支架。通过简单地改变端盖来改变聚合物对刺激的响应的能力，将在我们制备和研究对不同刺激做出响应的广泛的新材料的能力方面提供比当前聚合物显著的优势。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显著放大刺激，使材料性质的变化能够在较低的细胞兼容刺激浓度下发生。总体而言，这项研究将使我们对刺激响应材料的理解取得革命性的进步，同时为目标应用提供新的特性和功能。