利用原子转移自由基聚合(ATRP)方法合成了新的温度敏感性聚合物聚(2-甲基-2-丙烯酸-2-(2-甲氧基乙氧基)乙酯-co-寡聚乙二醇甲醚甲基丙烯酸酯-co-N-羟甲基丙烯酰胺)[ P ( MEO2 MA-co-OEGMA-co-HMAM)]。红外光谱( FTIR)、核磁共振谱(1 H NMR)和凝胶渗透色谱( GPC)对其结构进行了表征；利用透光率测定研究了共聚物的温度敏感性以及盐对其低临界溶解温度(LCST)的影响。将共聚物P(MEO2MA-co-OEGMA-co-HMAM)链上的羟基分别转化为叠氮基和炔基后，在抗坏血酸钠和CuSO4的催化条件下，通过温敏性共聚物P( MEO2 MA-co-OEGMA-co-HMAM)链间点击自交联反应获得了温敏性水凝胶。凝胶形成流变动力学研究发现凝胶化作用在1 min之内发生，之后体系的储能模量( G′)大于损耗模量( G″)；通过SEM和溶胀性能分析表明，随着温度的升高水凝胶的孔径减小，导致水凝胶的保水量逐渐减小，证明了合成的凝胶具有温度敏感性；牛血清蛋白( BSA)和茴香脑分别作为亲水和疏水药物模型研究凝胶的药物体外持续释放。结果表明：在37 o C时，载药凝胶对BSA释放率较大，释放速度较快。%A novel temperature responsive copolymer,poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol)meth-acrylate-co-N-hydroxymethylacrylamide) [ P ( MEO2 MA-co-OEGMA-co-HMAM ) ] , was synthesized by atom transfer radical poly-merization(ATRP). The copolymer was characterized by FTIR,1H NMR,and gel permeation chromatography(GPC). Temperature sensitivity for the copolymer and the effects of salts on the lower critical solution temperature( LCST) of copolymer aqueous solutions were studied by transmittance measurements at different temperatures. Then,the hydroxyl groups on P(MEO2MA-co-OEGMA-co-HMAM) chains were transformed into azide or alkyne groups respectively. A temperature-sensitivity self-cross linking hydrogel was prepared by click chemistry among the copolymers P(MEO2MA-co-OEGMA-co-HMAM). Rheological kinetics of gel formation dem-onstrated that gelation had commenced within 1 minutes,and since then the storage modulus( G′) was higher than the loss modulus (G″). The pore size and swelling ratio of the prepared hydrogels decreased with increasing the temperature because hydrophobic polymer-polymer interactions results in the self-aggregation of PMOH chains at a higher temperature ( T>LCST ) , that proved the formed hydrogel had temperature sensitivities. BSA and anethole respectively were used as a model hydrophilic and hydrophobic drug to examine in vitro the sustained release from hydrogel. Results showed that the anethole release rate from hydrogel within 10 h at 37℃ was slower than BSA.
展开▼
