National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China.
Macromol Biosci. 2014 Feb;14(2):289-97. doi: 10.1002/mabi.201300270. Epub 2013 Aug 14.
Star-shaped amphiphilic block copolymers with polyhedral oligomeric silsesquioxanes (POSS) as cores are synthesized using the "arm-first" strategy. First, the block copolymer poly(benzyl L-aspartate)-block-poly(ethylene glycol) (PBLA-b-PEG) is synthesized via ring-opening polymerization of β-benzyl L-aspartate-N-carboxyanhydride (BLA-NCA) with α-methoxy-ω-aminopoly(ethylene glycol) (mPEG-NH2 ) as a macroinitiator. The copolymers are then immobilized on the eight groups of the polyhedral oligomeric silsesquioxanes (POSS-COOH). The star-shaped copolymers (POSS-g-(PBLA-b-PEG)) are characterized by (1) H NMR and FT-IR spectroscopy and gel permeation chromatography. The star-shaped block copolymers self-assemble into micelles in aqueous medium. Quercetin is used as a model drug and the drug loading content and encapsulation efficiency increases with increasing chain length of the PBLA blocks. The drug release behaviors of drug loaded micelles are investigated and the cytotoxicity assay demonstrates that the POSS-g-(PBLA-b-PEG) copolymers are non-toxic. The star-shaped block copolymers are potential carriers for anticancer drug delivery.
以多面体低聚倍半硅氧烷（POSS）为核的星形两亲嵌段共聚物是采用“臂先法”合成的。首先，通过 α-甲氧基-ω-氨基聚（乙二醇）（mPEG-NH2）作为大分子引发剂开环聚合β-苄基 L-天冬氨酸-N-羧酸酐（BLA-NCA）合成嵌段共聚物聚（苄基 L-天冬氨酸）-嵌段-聚（乙二醇）（PBLA-b-PEG）。然后，将共聚物固定在多面体形聚倍半硅氧烷（POSS-COOH）的 8 个基团上。星形共聚物（POSS-g-（PBLA-b-PEG））通过 1H NMR 和 FT-IR 光谱以及凝胶渗透色谱进行了表征。星形嵌段共聚物在水介质中自组装成胶束。槲皮素用作模型药物，随着 PBLA 链段长度的增加，载药量和包封效率增加。考察了载药胶束的药物释放行为，细胞毒性测定表明 POSS-g-（PBLA-b-PEG）共聚物无毒。星形嵌段共聚物是用于抗癌药物递送的潜在载体。
