School of Chemistry and Chemical Engineering, State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Ji'nan 250353, China.
School of Chemistry and Chemical Engineering, State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Ji'nan 250353, China.
Int J Biol Macromol. 2024 Jan;256(Pt 1):128421. doi: 10.1016/j.ijbiomac.2023.128421. Epub 2023 Nov 25.
A pH-responsive amphiphilic chitosan derivative, N-lauric-O-carboxymethyl chitosan (LA-CMCh), is synthesized. Its molecular structures are characterized by FTIR, H 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 -NH groups are calculated based on the integrated data of H 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.
合成了一种 pH 响应性两亲性壳聚糖衍生物，N-月桂酰-O-羧甲基壳聚糖（LA-CMCh）。采用 FTIR、H NMR 和 XRD 方法对其分子结构进行了表征。考察了月桂酸（LA）、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）的用量、摩尔比、反应时间和反应温度对取代度的影响。根据 H NMR 谱图的积分数据计算了-NH 上的月桂酰基取代度（DS）。得到的最佳反应条件为：反应时间 6 h，反应温度 80℃，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，最大分解温度升高。结晶度降低是由于 LA 的引入和 LA-CMCh 分子间氢键的形成。LA-CMCh 可以自组装成颗粒，其大小和临界聚集浓度取决于取代度和介质 pH 值。LA-CMCh 可以负载姜黄素高达 21.70%，并持续释放姜黄素超过 200 min。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，表明其可用作油溶性药物载体。
