物理化学学报

所属专题: 热分析动力学和热动力学

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SDS对SB3-12胶束表面电荷密度的调控作用及对药物増溶的影响

邢肇碧1, 过治军1, 张雨微1, 刘君玲1, 王玉洁2, 白光月1   

  1. 1 河南师范大学化学化工学院, 精细化学品绿色制造河南省协同创新中心, 绿色化学介质与反应教育部重点实验室, 河南 新乡 453007;
    2 河南科技学院化学化工学院, 河南 新乡 453003
  • 收稿日期:2019-06-03 修回日期:2019-06-19 录用日期:2019-06-19 发布日期:2019-06-24
  • 通讯作者: 白光月, 王玉洁 E-mail:baiguangyue@htu.cn;yujiewang2001@163.com
  • 基金资助:
    国家自然科学基金(21773059,21273061,21327003)资助项目

Regulation of SDS on the Surface Charge Density of SB3-12 Micelles and Its Effect on Drug Dissolution

XING Zhaobi1, GUO Zhijun1, ZHANG Yuwei1, LIU Junling1, WANG Yujie2, BAI Guangyue1   

  1. 1 Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, Henan Province, P. R. China;
    2 School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, Henan Province, P. R. China
  • Received:2019-06-03 Revised:2019-06-19 Accepted:2019-06-19 Published:2019-06-24
  • Contact: BAI Guangyue, WANG Yujie E-mail:baiguangyue@htu.cn;yujiewang2001@163.com
  • Supported by:
    The project was supported by the National Natural Science Foundation of China (21773059, 21273061, 21327003).

摘要: 两性离子甜菜碱表面活性剂(SB3-12)胶束具有较好的生物相容性,由于相反电荷的极性头之间具有静电中和作用,胶束表面具有小的负电荷密度。当加入阴离子的十二烷基硫酸钠(SDS)以后,负离子SD-与SB3-12胶束极性区内层季铵正电荷的静电中和作用,能连续地调节胶束表面磺酸基的负电荷密度,这有利于对药物分子的选择性増溶和调节在生理条件下的药物的输送。等温滴定量热(ITC)研究发现SB3-12和SDS有强的协同效应,混合临界胶束浓度(CMC)和胶束化焓明显降低,并得到两者协同效应的弱静电作用机理。当模型药物分子芦丁(Rutin)与SB3-12/SDS混合胶束作用时,芦丁7位羟基的氢解离后的阴离子与SDS共同作用于SB3-12形成混合胶束。UV-Vis吸收光谱和1H NMR谱研究发现,在SB3-12胶束中,芦丁分子的A环位于季铵阳离子附近,B环位于两个相反电荷之间的弱极性区域。在SDS胶束中,B环位于栅栏层,而A环和二糖暴露于水相侧。在混合胶束中,随着SDS摩尔分数增加,对A环的静电吸引变弱。离子表面活性剂对两性离子表面活性剂胶束表面电荷密度的调节作用,本质上是对胶束极性区域的物理及化学性质的微调,进而实现对药物的可控增溶。

关键词: 两性离子表面活性剂, 混合胶束, 胶束表面电荷, 芦丁, ITC, 相互作用

Abstract: The micelles of zwitterionic betaine surfactant, SB3-12, have good biocompatibility and smaller negative charge density on the surface due to the electrostatic neutralization on the polar head that consists of two opposite charges. However, the available charge density on the micellar surface is essential for its application as a drug carrier owing to either the increased binding to cells or its favorable delivery into some specific organs under physiological conditions. This also facilitates the selective solubilization of drug molecules, depending on the interaction between the surfactant headgroup and drug molecule. When an anionic sodium dodecyl sulfate (SDS) is incorporated into SB3-12 micelles, the negative charge density of the micellar surface (from the sulfonic groups) can be continuously adjusted with a negative-positive order of the zwitterionic headgroup, where the electrostatic interaction occurs with the positively charged quaternary ammonium in the inner layer of the micellar polar region. Accordingly, positive micelles with adjustable charge density could be obtained if a cationic surfactant is incorporated into the micelles of the zwitterionic surfactant with a positive-negative headgroup. Using isothermal titration calorimetry, it is determined that a strong synergistic interaction occurs between SB3-12 and SDS, followed by a significant decrease in the mixed critical micelle concentration (CMC) and micellization enthalpy, which is mainly caused by weak electrostatic interaction. The synergistic effect is similar to that in the case of oppositely charged surfactant mixtures; however, the mixtures of zwitterionic and ionic surfactants do not form catanionic precipitates even at an equimolar ratio. When rutin, a model drug, is added to the SB3-12/SDS solution mixture, both SDS and the negatively charged rutin, obtained from the dissociation of the hydrogen of 7-hydroxyl group of rutin, can together interact with SB3-12 forming mixed micelles. The dissolved rutin molecules do not change the mixed CMC and the solubility of rutin is approximately constant when the composition of the mixed surfactants is in the range of 0.5 < xSB3-12 < 1; however, these can significantly enhance the electrostatic interaction between the mixed micelle and rutin molecule as xSB3-12 decreases. This can possibly allow the controlled release of rutin. UV-visible absorption spectroscopy and 1H NMR spectroscopy reveal that in SB3-12 micelles, the A ring of rutin is located near the positively charged quaternary ammonium group of SB3-12, and the B ring is located between the oppositely charged headgroups of SB3-12. In SDS micelles, the B ring is located on the palisade layer and the A ring and disaccharide are exposed to the aqueous phase. For the mixed SB3-12/SDS micelles, as the molar fraction of SDS increases, the electrostatic attraction toward the A ring weakens. The role of ionic surfactant in adjusting the surface charge density of the zwitterionic surfactant micelles allows the fine-tuning of the physical and chemical properties of polar micellar region, thereby exhibiting the potential for selective solubilization and controlled release of drugs.

Key words: Zwitterionic surfactant, Mixed micelle, Micellar surface charge, Rutin, ITC, Interaction

MSC2000: 

  • O642