Lim Young H, Heo Gyu Seong, Cho Sangho, Wooley Karen L
Departments of Chemistry and Chemical Engineering, Texas A&M University, College Station, Texas 77842, United States.
ACS Macro Lett. 2013 Aug 19;2(9). doi: 10.1021/mz400229m.
The development of a diblock copolymer, polyphosphoester--poly(L-lactide), which has potential for being fully-degradable and biocompatible, was achieved by one-pot sequential ring-opening polymerizations (ROPs) of two cyclic monomers: alkyne-functionalized phospholane and L-lactide (LLA). A kinetic study of the polymerization in each step was investigated in a detailed manner by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC), revealing living/controlled characteristics with narrow molecular weight distributions and a linear increase of molecular weights monomer conversion and time. Subsequently, photo-induced thiol-yne "click" reactions with small molecule thiols bearing either carboxylic acid or amino groups afforded amphiphilic diblock copolymers with carboxylate or amino side-chain functionalities along the polyphosphoester segment of the diblock copolymer backbone. Finally, direct dissolution of the two different types of amphiphilic diblock copolymers in aqueous solutions yielded well-defined spherical micelles with corresponding negative or positive surface charges, respectively, as confirmed by transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential analyses.
通过两种环状单体——炔基官能化环磷烷和L-丙交酯（LLA）的一锅法顺序开环聚合（ROP），制备了一种具有完全可降解和生物相容性潜力的二嵌段共聚物聚磷酸酯-聚（L-丙交酯）。通过核磁共振（NMR）光谱和凝胶渗透色谱（GPC）对每一步聚合反应进行了详细的动力学研究，结果表明该聚合反应具有活性/可控特性，分子量分布窄，分子量随单体转化率和时间呈线性增加。随后，通过与带有羧酸或氨基的小分子硫醇进行光诱导硫醇-炔“点击”反应，在二嵌段共聚物主链的聚磷酸酯链段上得到了具有羧酸根或氨基侧链官能团的两亲性二嵌段共聚物。最后，将两种不同类型的两亲性二嵌段共聚物直接溶解在水溶液中，分别得到了具有相应负表面电荷或正表面电荷的明确球形胶束，这通过透射电子显微镜（TEM）、动态光散射（DLS）和zeta电位分析得到了证实。
