NCA开环聚合制备聚糖-聚氨基酸嵌段共聚物及其功能性研究

聚糖-聚氨基酸嵌段共聚物具有高生物相容性，在医用水凝胶、纳米药物载体、生物组织工程等领域有广阔的应用前景。本课题将利用直链型葡聚糖特有的链末端反应位点C6位伯羟基，借助区域选择性反应，合成末端含有胺基的葡聚糖，并探究其作为NCA开环聚合引发剂的性质，包括分子量控制、单体选择性、引发效率、聚合反应活性等。利用NCA开环聚合对聚氨基酸合成的有效控制，实现对聚糖-聚氨基酸嵌段共聚物的化学结构调控。进一步研究该共聚物化学结构与构象及功能性的关系，明晰其二级结构的形成机制，探讨聚糖与聚氨基酸间的协同作用。初步探究将该嵌段共聚物制备为纳米颗粒用于药物载体的可行性。本研究设计了一种合成聚糖-聚氨基酸嵌段共聚物的新方法，为新型生物医用载体材料的设计提供理论依据。

Polysaccharide-polypeptide is a type of biocompatible copolymer which has promising application potential in hydrogel， drug delivery and biomedical applications. This proposal will focus on developing a synthetic route that enable preparation of polysaccharide-peptide block copolymer. Chemo and regio-selective functionalization of dextran C6 primary hydroxy group provides an access to modify the non-reducing end with desired motifs, like polymerization initiators and click chemistry functional groups. NCA ring opening polymerization is a well-known versatile and efficient method for preparing polypeptide. In this study, we apply NCA polymerization to polysaccharide and design a dextran macro-initiator, to prepare the polysaccharide-b-polypeptide. The structure-property relationship of dextran-peptide block copolymer will be fully investigated (secondary structure) and its application as nanoparticle drug carrier will be studied as well. Overall, this proposal will develop a well-defined synthetic method for building polysaccharide-polypeptide block copolymer, and explore the collaboration effects between these two biocompatible polymers. This study will make a significant contribution to functional biomedical materials.