层层自组装多层膜的制备及其功能化研究

发布时间：2018-03-04 01:15

本文选题：层层自组装　切入点：药物传递　出处：《新疆大学》2015年硕士论文　论文类型：学位论文

【摘要】：层层自组装(Layer-by-Layer self-assembly,Lb L)技术作为一种操作简易、选材繁多、膜厚及形状可控、可根据需要功能化的多层膜制备方法已被人们广泛接受。本论文以Lb L技术为基础构建多种多层膜,并研究了它们在药物传递、光学、电化学领域方面的应用。主要研究内容如下:(1)目前Lb L技术在药物传递领域的应用日益彰显。在本实验室前期工作的基础上,本章节进一步探讨了膜组分的分子结构等物化性质对所制备多层膜药物装载量性能的影响。以生物兼容性聚氨酯(PU)为研究对象,分别与三种具有不同结构的多糖:透明质酸钠(Na HA)、羧甲基纤维素钠(CMC)和海藻酸钠(ALG),配对制备聚氨酯/多糖系列的Lb L多层膜;以亚甲基蓝(MB)作为模型药物,考察了PU/NaHA、PU/CMC、PU/ALG三种多层膜在不同pH、离子强度下对MB的吸附性能。结果表明尽管三种膜对MB的吸附均符合Langmuir吸附和伪二级动力学方程模型,但多糖分子结构中官能团种类及数量是影响膜载药性能的关键因素。(2)采用Lb L技术构建了新型的光致变色聚乙烯亚胺/磷钨酸(PEI/PTA)多层膜。通过紫外可见光谱、红外光谱、X射线光电子能谱测试手段对多层膜进行表征。将该膜置于紫外光的照射下,PEI/PTA多层膜逐渐的由无色变为蓝色,并在710 nm出现特征吸收峰。PEI/PTA多层膜光致变色机理为电荷转移桥上的胺基的质子氢通过该桥转移给多酸的氧原子,使得W6+被还原成W5+,对应于杂多酸分子被还原成杂多蓝。当膜置于空气或者O2环境下,膜会自发地由蓝色变为无色。经过10次的变色、褪色循环后,该膜的吸光值依然保持稳定,表明PEI/PTA多层膜具有良好的稳定性和光致变色可逆性能。(3)将PEI/PTA多层膜构建于ITO玻璃片上作为一类新型的电化学传感器,采用循环伏安测试方法对其电化学性能进行研究。采用该膜修饰的电极分别对溶液中的双氧水(H2O2)及L-抗坏血酸(AA)进行检测,结果得出线性范围分别为3.5×10-3 3.5×10-2 mg/mL和1.0×10-3 1.2×10-2 mg/mL,检出限达到:8.4×10-4mg/mL和6.4×10-4 mg/mL,采用标准加入法得到平均回收率分别为99.64%和100.15%。将该电极应用于对市售的几种果蔬饮料中的AA含量的检测,并采用高效液相色谱法(HPLC)对其进行验证,结果表明两种方法间不存在显著性差异。与文献相比,PEI/PTA多层膜对于电催化还原H2O2和电催化氧化AA均表现出高灵敏性、高稳定性及可重复使用性的特点,说明PEI/PTA多层膜修饰的电极可作为潜在的氧化性和还原性物质的电化学传感器。
[Abstract]:Layer-by-Layer self-assembly LbL (Lb-L) technology is widely accepted as a kind of multilayer film preparation method, which can be functionalized according to the needs of LbL technology, because of its simple operation, wide selection of materials, controllable film thickness and controllable shape. Their applications in the fields of drug delivery, optics and electrochemistry are also studied. The main research contents are as follows: 1) at present, the application of LbL technology in the field of drug delivery is becoming more and more obvious. On the basis of previous work in our laboratory, In this chapter, the effects of physicochemical properties such as molecular structure of membrane components on the drug loading performance of multilayer membranes were investigated. The biocompatible polyurethane (PUU) was used as an object of study. Three kinds of polysaccharides with different structures: sodium hyaluronate, sodium carboxymethyl cellulose (CMC) and sodium alginate (ALGG) were paired to prepare LbL multilayer membranes of polyurethane / polysaccharide series. The adsorption properties of the three kinds of multilayer membranes for MB at different pH and ionic strength were investigated. The results showed that the adsorption of the three kinds of membranes to MB was in accordance with the Langmuir adsorption and pseudo-second-order kinetic equation model. However, the type and number of functional groups in the molecular structure of polysaccharides are the key factors affecting the drug loading performance of the membrane. (2) A novel photochromic polyvinyleneimine / phosphotungstic acid PEI / PTAs multilayer films were constructed by LbL technique. Infrared spectrum X-ray photoelectron spectroscopy (XPS) was used to characterize the multilayer film. The PEI / PTA multilayer film gradually changed from colorless to blue under the irradiation of ultraviolet light. The photochromic mechanism of PEI / PTA multilayer film at 710 nm is that the proton hydrogen of amine group on the charge transfer bridge is transferred to the oxygen atom of polyacid, so that W6 is reduced to W5. Corresponding to the reduction of heteropoly acid molecules to heteropoly blue. When the film is placed in the air or O2 environment, the film will spontaneously change from blue to colorless. After 10 times of discoloration and fading cycle, the absorptivity of the film remains stable. The results show that the PEI/PTA multilayer film has good stability and photochromic reversible property. The PEI/PTA multilayer film is constructed on the ITO glass as a new type of electrochemical sensor. The electrochemical performance was studied by cyclic voltammetry. The modified electrodes were used to detect hydrogen peroxide (H 2O 2) and L-ascorbic acid (AA), respectively. The results showed that the linear ranges were 3.5 脳 10 ~ (-3) mg/mL and 1.0 脳 10 ~ (-3) C ~ (-1) 脳 10 ~ (-2) mg 路mL ~ (-1), with detection limits of: 8.4 脳 10 ~ (-4) mg / mL and 6.4 脳 10 ~ (-4) mg / mL, respectively. The average recoveries were 99.64% and 100.15 mg / mL by standard addition method, respectively. The electrode was applied to the determination of AA in several kinds of fruit and vegetable drinks sold in the market. The results showed that there was no significant difference between the two methods. Compared with the literature, the PEI / PTA multilayer membrane was highly sensitive to the electrocatalytic reduction of H2O2 and the electrocatalytic oxidation of AA. The characteristics of high stability and repeatability indicate that the electrode modified by PEI/PTA multilayer film can be used as a potential electrochemical sensor for oxidizing and reducing substances.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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