Polymer micelle-like aggregates of novel amphiphilic biodegradable poly(asparagine) grafted with poly(caprolactone)
Polymer micelle-like aggregates of novel amphiphilic biodegradable poly(asparagine) grafted with poly(caprolactone)
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DOI：
10.1016/s0032-3861(02)00816-9
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发表时间：
2003
期刊：
影响因子：
4.6
通讯作者：
J. Jeong;H. Kang;S. Yang;Jong-Duk Kim
中科院分区：
文献类型：
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作者：
J. Jeong;H. Kang;S. Yang;Jong-Duk Kim
通过将聚己内酯（PCL）与聚丁二酰亚胺（PB）接枝，合成了以聚天冬酰胺（PAsn）为亲水主链、聚己内酯（PCL）为疏水链段的两亲性接枝共聚物。对甲苯磺酰氯（TsCl）对PCL-二醇进行甲苯磺酰化后，再与己二胺（HMD）进行甲苯磺酰化聚己内酯（PCL-OTs）。将端胺基PCL与聚丁二酰亚胺（PSI）反应，再进行氨解反应，制得了端胺基PCL接枝聚己内酯（PAsn-g-PCL）。用13 CNMR、FT-IR和元素分析等方法对接枝反应和取代度进行了表征。X射线衍射和DSC热分析表明，随着DS的增加，源于PCL的结晶结构域变得明显。两亲性梳型接枝聚合物在水溶液中形成自聚集体时，沉淀和对蒸馏水透析。相关的PCL接枝物的强疏水相互作用促进初级聚集体形成与DS，显着降低临界聚集浓度和二次聚集体也出现在DLS测量。自聚集体显示出双峰粒径分布起源于自聚集和动力学控制的颗粒聚集，虽然较小的初级聚集体占主导地位。通过透射电子显微镜观察到直径约20 nm的球形和分散的聚集体。
Novel amphiphilic graft copolymers composed of poly(asparagine) (PAsn) as the hydrophilic backbone and poly(caprolactone) (PCL) as the hydrophobic segment were successfully synthesized by grafting PCL–HMDs to poly(succinimde). After tosylating PCL-diol with p-toluenesulfonylchloride (TsCl), tosylated poly(caprolactone) (PCL–OTs) was then reacted with hexamethylenediamine (HMD). The reaction of the amine terminated PCL with poly(succinimide) (PSI) and the following aminolysis resulted in poly(aspargine)-graft-poly(caprolactone) (PAsn-g-PCL). The degree of substitution (DS) and grafting reaction was confirmed by13C NMR, FT-IR spectroscopy and elemental analysis. X-ray diffraction and DSC thermogram showed that the crystalline domain originated from PCL became apparent with an increase of DS. The amphiphilic comb-type graft polymer formed self-aggregates in aqueous solution when precipitated and dialysed against distilled water. Strong hydrophobic interaction of associated PCL grafts facilitated primary aggregate formation with DS, significantly reducing critical aggregation concentration and secondary aggregates also appeared in DLS measurements. Self-aggregates showed a bimodal size distribution originated from the self-aggregation and kinetically controlled particle aggregation, although the smaller primary aggregates was predominant. Spherical and dispersed aggregates of about 20nm in diameter were observed by a transmission electron microscope.