Wang Fei, Bronich Tatiana K, Kabanov Alexander V, Rauh R David, Roovers Jacques
EIC Laboratories, Inc., 111 Downey Street, Norwood, Massachusetts 02062, USA.
Bioconjug Chem. 2005 Mar-Apr;16(2):397-405. doi: 10.1021/bc049784m.
A star polymer composed of amphiphilic block copolymer arms has been synthesized and characterized. The core of the star polymer is polyamidoamine (PAMAM) dendrimer, the inner block in the arm is lipophilic poly(epsilon-caprolactone) (PCL), and the outer block in the arm is hydrophilic poly(ethylene glycol) (PEG). The star-PCL polymer was synthesized first by ring-opening polymerization of epsilon-caprolactone with a PAMAM-OH dendrimer as initiator. The PEG polymer was then attached to the PCL terminus by an ester-forming reaction. Characterization with SEC, (1)H NMR, FTIR, TGA, and DSC confirmed the star structure of the polymers. The micelle formation of the star copolymer (star-PCL-PEG) was studied by fluorescence spectroscopy. Hydrophobic dyes and drugs can be encapsulated in the micelles. A loading capacity of up to 22% (w/w) was achieved with etoposide, a hydrophobic anticancer drug. A cytotoxicity assay demonstrated that the star-PCL-PEG copolymer is nontoxic in cell culture. This type of block copolymer can be used as a drug delivery carrier.
一种由两亲性嵌段共聚物臂组成的星形聚合物已被合成并表征。星形聚合物的核心是聚酰胺-胺（PAMAM）树枝状大分子，臂中的内嵌段是亲脂性的聚（ε-己内酯）（PCL），臂中的外嵌段是亲水性的聚（乙二醇）（PEG）。首先以PAMAM-OH树枝状大分子为引发剂，通过ε-己内酯的开环聚合反应合成了星形-PCL聚合物。然后通过酯形成反应将PEG聚合物连接到PCL末端。用尺寸排阻色谱法（SEC）、核磁共振氢谱（¹H NMR）、傅里叶变换红外光谱（FTIR）、热重分析（TGA）和差示扫描量热法（DSC）进行表征，证实了聚合物的星形结构。通过荧光光谱法研究了星形共聚物（星形-PCL-PEG）的胶束形成。疏水性染料和药物可以包封在胶束中。对于疏水性抗癌药物依托泊苷，实现了高达22%（w/w）的载药量。细胞毒性试验表明，星形-PCL-PEG共聚物在细胞培养中无毒。这种类型的嵌段共聚物可用作药物递送载体。
