Thermo reversible gel-sol behavior of biodegradable PCL-PEG-PCL triblock copolymer in aqueous solutions
Thermo reversible gel-sol behavior of biodegradable PCL-PEG-PCL triblock copolymer in aqueous solutions
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DOI：
10.1002/jbm.b.30858
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发表时间：
2008-01-01
影响因子：
3.4
通讯作者：
Qian, Zhi Yong
中科院分区：
文献类型：
--
作者：
Liu, Cai Bing;Gong, Chang Yang;Qian, Zhi Yong
以聚乙二醇（PEG）为引发剂，通过ε-己内酯开环聚合，成功合成了一系列可生物降解的PCL-PEG-PCL嵌段共聚物，并用H-1 NMR、C-13 NMR和FTIR对其进行了表征。当聚合物浓度高于相应的临界凝胶浓度（CGC）时，其水溶液在4 ~ 100 ℃范围内表现出特殊的凝胶-溶胶转变行为。用试管倒置法和DSC法记录了共聚物的凝胶-溶胶相图，该相图不仅与共聚物的化学组成有关，而且与共聚物水溶液的加热历史有关。结果表明，该聚合物的凝胶转变温度可调，这对于其在生物医学领域如注射给药系统中的应用具有重要意义。介绍了PCL-PEG-PCL胶束的典型壳-核结构。胶束堆积和部分结晶可能是PCL-PEG-PCL水溶液凝胶-溶胶转变行为的关键机理。(c)2007 Wiley Periodicals，Inc.
A series of biodegradable PCL-PEG-PCL block copolymers were successfully synthesized by ring-opening polymerization of e-caprolactone initiated by poly(ethylene glycol) (PEG), which were characterized by H-1 NMR, C-13 NMR, and FTIR. Their aqueous solution displayed special gel-sol transition behavior with temperature increasing from 4 to 100 degrees C, when the polymer concentration was above corresponding critical gel concentration (CGC). The gel-sol phase diagram was recorded using test tube inverting method and DSC method, which depended not only on chemical composition of copolymers, but also on heating history of copolymer's aqueous solution. As a result, the gel-so] transition temperature could be adjusted, which might be very useful for its application in biomedical fields such as injectable drug delivery system. And the typical shell-core structure of PCL-PEG-PCL micelles was introduced. The micelle-packing and partial crystallization might be the key gelation machanism for this gel-sol transition behavior of PCL-PEG-PCL aqueous solution. (c) 2007 Wiley Periodicals, Inc.