Thermoreversible gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions
Thermoreversible gelation of PEG-PLGA-PEG triblock copolymer aqueous solutions
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DOI：
10.1021/ma9908999
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发表时间：
1999-10-19
期刊：
影响因子：
5.5
通讯作者：
Kim, SW
中科院分区：
文献类型：
--
作者：
Jeong, B;Bae, YH;Kim, SW
新型可生物降解三嵌段共聚物聚乙二醇-b-（dl -乳酸-共乙醇酸）-b-乙二醇（PEG-PLGA-PEG）的水溶液随着温度单调升高，表现出溶胶-凝胶（下过渡）和凝胶-溶胶（上过渡）的转变。较低的转变对药物输送应用很重要，因为溶液在室温下自由流动，在体温下变成凝胶。本文提出了凝胶化的机理，并对溶胶-凝胶过渡的结构-性能关系进行了研究。下层转变可能与胶束生长、胶束内和胶束间相混合和堆积有关，上层转变则与胶束结构的破坏有关。临界凝胶浓度和临界凝胶温度由聚合物分子参数（如PEG-PLGA-PEG三嵌段共聚物的嵌段长度和组成）和添加剂（如盐）控制。
Aqueous solutions of new biodegradable triblock copolymers, poly(ethylene glycol-b-(DL-lactic acid-co-glycolic acid)-b-ethylene glycol) (PEG-PLGA-PEG), have shown to have sol-to-gel (lower transition) and gel-to-sol (upper transition) transitions as temperature monotonically increases. The lower transition is important for drug delivery application because the solution flows freely at room temperature and becomes a gel at body temperature. In this paper, the mechanism of gelation was proposed, and the structure-property relationship of the sol-gel transition was investigated. The lower transition may be related to micellar growth and intra- and intermicelle phase mixing and packing, while the upper transition involves breakage of micellar structure. Critical gel concentration and critical gel temperature are controlled by polymer molecular parameters, such as block length and composition of PEG-PLGA-PEG triblock copolymers, and additives, such as salts.