Copolymers of N-isopropylacrylamide, HEMA-lactate and acrylic acid with time-dependent lower critical solution temperature as a bioresorbable carrier
Copolymers of N-isopropylacrylamide, HEMA-lactate and acrylic acid with time-dependent lower critical solution temperature as a bioresorbable carrier
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DOI：
10.1002/pi.1709
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发表时间：
2005-02-01
影响因子：
3.2
通讯作者：
Vernon, B
中科院分区：
文献类型：
--
作者：
Lee, BH;Vernon, B
以N-异丙基丙烯酰胺（NIPAAm）、甲基丙烯酸2-羟乙酯乳酸酯（HEMA-lactate）和丙烯酸（AAc）为单体，通过改变单体的摩尔比，制备了具有时间依赖性的低临界溶解温度（LCST）的可生物吸收原位凝胶材料。用核磁共振、凝胶渗透色谱和差示扫描量热法对合成的共聚物进行了表征。在pH 7.4的0.1 M磷酸盐缓冲盐水溶液中，这些共聚物具有低于体温的LCST。随着共聚物中HEMA-乳酸酯含量的增加，LCST降低。此外，在这些条件下，由于HEMA-乳酸酯的水解，共聚物的LCST表现出时间依赖性。随着HEMA-乳酸盐水解，共聚物变得更加亲水，从而导致LCST增加。这种亲水性导致约6摩尔%的AAc的共聚物在水解后表现出高于体温的LCST。在中性溶液中，具有不同摩尔%的AAc的共聚物在一到十天内看到它们的LCST升高到37 ℃以上，这取决于HEMA-乳酸盐/NIPAAm的比率，这是由于HEMA-乳酸盐的完全水解。上述性质表明，这些共聚物可用于药物递送，因为它们的可变LCST使它们具有生物可吸收性。(C)2004化学工业协会。
Copolymers of N-isopropylacrylamide (NIPAAm), 2-hydroxyethyl methacryl lactate (HEMA-lactate) and acrylic acid (AAc) were prepared, with varying mole ratios of monomers, to develop a bioresorbable in-situ-gelling material with a time-dependent lower critical solution temperature (LCST). The synthesized copolymers were characterized by nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry. In 0.1 M phosphate-buffered saline solution of pH 7.4, these copolymers had an LCST below body temperature. The LCST decreased as the HEMA-lactate content of the copolymers was increased. Furthermore, in these conditions, the LCST of the copolymers exhibited time-dependent properties, due to hydrolysis of the HEMA-lactate. As the HEMA-lactate hydrolyzed, the copolymers became more hydrophilic, thereby leading to an increase in LCST. This hydrophilicity caused copolymers of approximately 6 mol% of AAc to exhibit an LCST above body temperature after hydrolysis. In neutral solution, copolymers with varying mol% of AAc saw their LCST rise above 37degreesC within one to ten days, depending upon the HEMA-lactate/NIPAAm ratio, due to the complete hydrolysis of the HEMA-lactate. The above properties indicate that these copolymers would be useful for drug delivery because their variable LCST makes them bioresorbable. (C) 2004 Society of Chemical Industry.