Synthesis and characterization of glycopolymer-polypeptide triblock copolymers
Synthesis and characterization of glycopolymer-polypeptide triblock copolymers
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DOI：
10.1021/bm0343500
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发表时间：
2004-01-01
影响因子：
6.2
通讯作者：
Chaikof, EL
中科院分区：
文献类型：
--
作者：
Dong, CM;Sun, XL;Chaikof, EL
通过原子转移自由基聚合（ATRP）和开环聚合（ROP）合成了聚（L-丙氨酸）-b-聚（2-丙烯酰氧乙基-乳糖苷）-b-聚（L-丙氨酸）（阿加）三嵌段共聚物。以二溴二甲苯（DBX）/CuBr/bipy络合物体系为引发剂，采用原子转移自由基聚合法（ATRP）对2-O-丙烯酰氧乙氧基-（2，3，4，6-四-O-乙酰基-β-D-吡喃半乳糖基）-（1-4）-2，3，6-三-O-乙酰基-β-D-吡喃葡萄糖苷（AEL）进行了控制自由基聚合。通过端基转化法得到了端氨基的双螺旋糖基共聚物，并将其用作L-丙氨酸-N-羧酸酐单体（Ala-NCA）的ROP大分子引发剂。凝胶渗透色谱（GPC）和核磁共振（NMR）分析表明，共聚物的分子量和组成受Ala-NCA单体与大分子引发剂的摩尔比和单体转化率的控制，且分布较窄（M-w/M-n = 1.06-1.26）。三嵌段共聚物的FT-IR光谱显示，α-螺旋/β-折叠的比例随着聚（L-丙氨酸）嵌段长度的增加而增加。值得注意的是，透射电子显微镜（TEM）表明，选定的两亲性二元醇共聚物-多肽三嵌段共聚物在水溶液中自组装，形成直径数百纳米的近球形聚集体。值得注意的是，ATRP和ROP技术的顺序应用提供了一种有效的方法，用于生产三嵌段共聚物，其具有中心糖基共聚物嵌段和限定结构、受控分子量和低多分散性的侧翼多肽嵌段。
Glycopolymer-polypeptide triblock copolymers of the structure, poly(L-alanine)-b-poly(2-acryloyloxyethyl-lactoside)-b-poly(L-alanine) (AGA), have been synthesized by sequential atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP). Controlled free radical polymerization of 2-O-acryloyl-oxyethoxyl-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-4)-2,3,6-tri-O-acetyl-beta-D-glucopyranoside (AEL) by ATRP with a dibromoxylene (DBX)/CuBr/bipy complex system was used to generate a central glycopolymer block. Telechelic glycopolymers with diamino end groups were obtained by end group transformation and subsequently used as macroinitiators for ROP of L-alanine N-carboxyanhydride monomers (Ala-NCA). Gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analysis demonstrated that copolymer molecular weight and composition were controlled by both the molar ratios of the Ala-NCA monomer to macroinitiator and monomer conversion and exhibited a narrow distribution (M-w/M-n = 1.06-1.26). FT-IR spectroscopy of triblock copolymers revealed that the ratio of alpha-helix/beta-sheet increased with poly(L-alanine) block length. Of note, transmission electron microscopy (TEM) demonstrated that selected amphiphilic glycopolymer-polypeptide triblock, copolymers self-assemble in aqueous solution to form nearly spherical aggregates of several hundreds nanometer in diameter. Significantly, the sequential application of ATRP and ROP techniques provides an effective method for producing triblock copolymers with a central glycopolymer block and flanking polypeptide blocks of defined architecture, controlled molecular weight, and low polydispersity.