一种pH响应性两亲性壳聚糖衍生物,N-月桂酸-O-羧甲基壳聚糖(LA-CMCh),是合成的。用FTIR对其分子结构进行了表征,1HNMR,和XRD方法。对影响因素进行了调查,包括月桂酸(LA)的量,羧甲基壳聚糖(CMCh),N-(3-二甲基氨基丙基)-N'-乙基碳二亚胺盐酸盐(EDC),和N-羟基琥珀酰亚胺(NHS),和它们的摩尔比,反应时间,和反应温度对取代。基于1HNMR光谱的积分数据计算-NH2基团上月桂基团的取代度(DS)。最佳反应条件为反应时间6h,反应温度为80°C,月桂酸与O-羧甲基壳聚糖与N-(3-二甲基氨基丙基)-N'-乙基碳二亚胺盐酸盐与N-羟基琥珀酰亚胺的摩尔比分别为1:3:4.5:4.5。LA-CMCh的结晶度和初始分解温度降低,但最高分解温度升高。由于LA的引入和LA-CMCh分子之间的氢键合程度,结晶度降低。LA-CMCh可以自聚集成颗粒,大小和临界聚集浓度取决于取代度和介质pH。LA-CMCh聚集体可以负载高达21.70%的姜黄素,并连续释放姜黄素>200分钟。LA-CMCh对成纤维细胞HFF-1细胞无毒性,对金黄色葡萄球菌和大肠杆菌具有良好的抗菌活性,表明它可以用作油溶性药物载体。
A pH-responsive amphiphilic chitosan derivative, N-lauric-O-carboxymethyl chitosan (LA-CMCh), is synthesized. Its molecular structures are characterized by FTIR, 1H NMR, and XRD methods. The influencing factors are investigated, including the amount of lauric acid (LA), carboxymethyl chitosan (CMCh), N-(3-dimethylaminopropyl)-N\'-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS), and their molar ratio, reaction time, and reaction temperature on the substitution. The degrees of substitution (DS) of the lauric groups on the -NH2 groups are calculated based on the integrated data of 1H NMR spectra. The optimum reaction condition is obtained as a reaction time of 6 h, a reaction temperature of 80 °C, and a molar ratio of lauric acid to O-carboxymethyl chitosan to N-(3-dimethylaminopropyl)-N\'-ethylcarbodiimide hydrochloride to N-hydroxysuccinimide of 1:3:4.5:4.5, respectively. The crystallinity and initial decomposition temperature of LA-CMCh decrease, but the maximum decomposition temperature increases. The crystallinity is reduced due to the introduction of LA and the degree of hydrogen bonding among LA-CMCh molecules. LA-CMCh could self-aggregate into particles, which size and critical aggregation concentration depend on the degree of substitution and medium pH. LA-CMCh aggregates could load curcumin up to 21.70 %, and continuously release curcumin for >200 min. LA-CMCh shows nontoxicity to fibroblast HFF-1 cells and good antibacterial activity against S. aureus and E. coli, indicating that it could be used as an oil-soluble-drug carrier.