A unimolecular nanocapsule : Encapsulation property of amphiphilic polymer based on hyperbranched polythreitol
A unimolecular nanocapsule : Encapsulation property of amphiphilic polymer based on hyperbranched polythreitol
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DOI：
10.1016/j.polymer.2007.06.026
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发表时间：
2007-07
期刊：
影响因子：
4.6
通讯作者：
Y. Kitajyo;Yumiko Nawa;M. Tamaki;H. Tani;Kenji Takahashi;H. Kaga;T. Satoh;T. Kakuchi
中科院分区：
文献类型：
--
作者：
Y. Kitajyo;Yumiko Nawa;M. Tamaki;H. Tani;Kenji Takahashi;H. Kaga;T. Satoh;T. Kakuchi
不同分子量（Mw,SLS: 1.18×104and 4.79×104）的超支化聚苏糖醇(1)在DMF中与三氯甲烷反应，得到了一种新型的两亲性聚合物(2)，该聚合物以1为亲水核，三烷基为疏水壳。化合物2作为单分子纳米胶囊对水溶性染料玫瑰红（RB）的作用进行了测试。通过与三烷基取代度（DS）即疏水壳密度的比较，评价了它们的包封性和释放性。研究发现，即使在极低的浓度下，聚合物也具有很好的单分子纳米胶囊特性。每个聚合物分子的平均RBs数取决于亲水性核的大小和疏水性壳的密度。随着DS值的增加，由于亲水性核心空间的减小，导致包被量的减少，而低DS值（小于约20mol%）导致单分子纳米胶囊不稳定，包被能力降低。其中，DS值约为23%的2包封效果较好。基于负载rb的单分子纳米胶囊的释放测试，聚合物在水中表现出较高的rb保持能力。
Hyperbranched polythreitol (1) with different molecular weights (Mw,SLS: 1.18×104and 4.79×104) was reacted with trityl chloride in DMF to afford a novel amphiphilic polymer (2) consisting of 1 as the hydrophilic core and the trityl groups as the hydrophobic shell. Compound 2 was tested for its ability to act as a unimolecular nanocapsule toward the water-soluble dye, rose bengal (RB). Their encapsulation and release properties were also evaluated by comparison with the degree of substitution (DS) of the trityl groups, i.e., the hydrophobic shell density. The polymers were found to have very good unimolecular nanocapsule characteristics even at extremely low concentrations. The average number of RBs per polymer molecule depended on the hydrophilic core size and the hydrophobic shell density. The increasing DS value led to a decrease in the encapsulated amount due to the decrease in the hydrophilic core space, while the low DS value (less than ca. 20mol%) led to a destabilization as a unimolecular nanocapsule and a lower encapsulation ability. In particular, 2 with ca. 23% DS value showed an efficient encapsulation. Based on a release test of the RB-loaded unimolecular nanocapsules, the polymers showed a high RB-holding ability in water.