Tunable Biocompatible and Biodegradable Thermoresponsive Polycaprolactones

美国国家科学基金会化学部的大分子、超分子和纳米化学项目支持德克萨斯大学达拉斯分校的Mihaela C.Stefan和Michael C.Biewer教授开发可生物降解和生物兼容的聚合物。感兴趣的聚合物包含亲水(亲水)和疏水(疏水)链段，可以在水中组装形成核-壳结构，其中可以负载水不溶分子。这些聚合物最吸引人的特性是它们在水介质中的降解性，使它们成为环境友好的材料。该项目为研究生和本科生提供有机化合物和聚合物的合成和表征方面的培训。高中生有机会在暑期研究项目中做出贡献，在化学实验室环境中学习技能。这项拟议的研究的目标是开发可生物降解、生物相容性和热响应性的聚己内酯两亲嵌段共聚物。该研究小组的目标是通过改变亲水低聚乙二醇聚己内酯亲水嵌段和疏水聚己内酯嵌段之间的比例来控制两亲性嵌段共聚物的热响应性。为了了解嵌段共聚物的结构和组成对降解率的依赖关系，该团队研究了将单体上的取代基键从乙醚改变为硫醚，从酯改变为硫酯对聚合物降解率的影响。此外，对合成的两亲性聚己内酯嵌段共聚物的自组装进行了研究，得到了分子结构与胶束大小之间的关系。

The Macromolecular, Supramolecular and Nanochemistry Program in the NSF Division of Chemistry supports Professors Mihaela C. Stefan and Michael C. Biewer of the University of Texas at Dallas to develop biodegradable and biocompatible polymers. The polymers of interest contain both water-friendly (hydrophilic) and water repellent (hydrophobic) segments can assemble in water to form core-shell structures in which the water-insoluble molecules can be loaded. The most attractive property of these polymers is their degradation in water media making them environmentally friendly materials. The project provides training to graduate and undergraduate students in the synthesis and characterization of organic compounds and polymers. High school students are given the opportunity to contribute in a summer research project to learn skills in a chemistry laboratory environment.The objective of this proposed research is to develop polycaprolactone amphiphilic block copolymers that are biodegradable, biocompatible, and thermoresponsive. The research team aims to control the thermoresponsivity of the amphiphilic block copolymers by varying the ratio between the hydrophilic oligoethylene glycol substituted polycaprolactone hydrophilic block and the hydrophobic polycaprolactone block. To understand the dependence of the degradation rate on the structure of the block copolymers and their composition, the team investigates the effects of changing the linkage of the substituent on the monomers from ether to thioether, and from ester to thioester, on the polymer degradation rate. In addition, investigation of the self-assembly of the synthesized amphiphlic polycaprolactone block copolymers is conducted to obtain a correlation between the molecular structure and the size of micelles.