ropatrp联用制备基于聚磷酸酯的嵌段共聚物及其应用分析-preparation and application analysis of block copolymer based on polyphosphate ester by ropa trp.docx

Abstract Synthesis of Block Copolymers Based on Polyphosphesters via ROP and ATRP for Drug and Gene DeliveryFT-IR and GPC measurements. Subsequently, pH-responsive micellization behaviors of PEEP-b-PSEMA diblock copolymers were investigated by fluorescence probe method, DLS and TEM measurements. The results demonstrated that these diblock copolymers were able to self-assemble into micelles with various sizes depending on the variation of pH values. Naproxen (NAP), a poorly water-soluble drug, was selected as the model drug and encapsulated into the core of micelles via dialysis method. The in vitro release behavior of NAP from these micelles was pH-dependent and could be accelerated in the presenceof phosphodiesterase I which can promote the degradation of polyphosphoesters. Cytotoxicity tests by MTT assay showed that these block copolymers possessed favorable biocompatibility against HeLa cells, revealing that this kind of biodegradable, biocompatible and pH-responsive block copolymer would be served as a promising material for drug delivery.Part 2. Synthesis of Amphiphilic Triblock Copolymers PEEP-b-PCL-b-PDMAEMAAmphiphilic triblock copolymers PEEP-b-PCL-b-PDMAEMA were prepared by a combination of ROP and ATRP. Firstly, the bifunctional initiator HEBI was used to initiate the ring opening polymerization of ε-CL using Sn(Oct)2 as catalyst to prepare the homopolymer with hydroxyl group and bromo group in each chain end of PCL (HO-PCL-Br). PEEP-b-PCL-Br diblock copolymer was then synthesized by ROP of EOP using HO-PCL-Br as macroinitiator and Sn(Oct)2 as catalyst. Finally, the amphiphilic triblock copolymer PEEP-b-PCL-b-PDMAEMA was obtained by the ATRP of DMAEMA using PEEP-b-PCL-Br as the macroinitiator and CuBr/bpy as the catalystsystem．1H NMR and gel permeation chromatography (GPC) measurements wererespectively utilized to determine their chemical structures, molecular weights and molecular weight distributions. Self-assembly behaviors of the triblock copol