离子交联法制备聚唾液酸/壳聚糖纳米粒

以聚唾液酸和壳聚糖为原料,多聚磷酸钠为交联剂,采用离子交联法制备聚唾液酸/壳聚糖纳米粒。结果表明:当聚唾液酸质量浓度为1.25 mg/mL,壳聚糖质量浓度为1.00 mg/mL,壳聚糖与聚唾液酸质量比为2∶1,多聚磷酸钠质量浓度为0.15 mg/mL,滴加速度为1滴/s时,所制备的聚唾液酸/壳聚糖纳米粒粒径最小,平均粒径为217.2 nm,纳米粒粒径分散指数为0.236。以牛血清白蛋白(BSA)为模型药物,包封率为(44.95±1.22)%,载BSA率为(28.90±0.78)%。离子交联法制备聚唾液酸/壳聚糖纳米粒操作简单快捷,不使用有机溶剂,所得纳米粒粒径较小,有望成为蛋白类药物的载体。     

自组装法制备CMCS/PEG纳米粒子及其pH值响应性研究

以壳聚糖(CS)为原料与氯乙酸反应制备羧甲基壳聚糖(CMCS),再将聚乙二醇(PEG)和CMCS以不同的质量比溶解在不同pH值的溶液中,通过氢键相互作用自组装形成CMCS/PEG纳米粒子,并研究其粒径大小与二者配比和溶液pH值之间的关系。结果表明,不同配比下的粒子粒径均随pH值的增大先增大后减小;当pH5时,在相同pH值溶液中,随着PEG比例的增加,粒子的粒径先减小后增大,在pH=1.22、PEG∶CMCS=4∶1时粒径最小,约为160nm;当pH≥5时,在相同pH值溶液中,粒径随PEG用量的增加而增大;通过自组装法制备的CMCS/PEG纳米粒子粒径大小具有pH值响应性。     

载脂肪酶壳聚糖/海藻酸钙微胶囊的制备

针对固定化脂肪酶的研究背景,以壳聚糖、海藻酸钠为微载体制备材料,采用脉冲电场液滴工艺制备壳聚糖/海藻酸钙微胶囊。以脂肪酶为生物模型,系统考察了制备条件对载脂肪酶壳聚糖/海藻酸钙微胶囊酶活力的影响。结果表明:海藻酸钠质量浓度和酶与海藻酸钠载体配比是影响固定化酶活力的主要因素,载酶量为15mg/mL,海藻酸钠质量浓度为10mg/mL时载酶微胶囊酶活力最高,球形度好。通过改变壳聚糖质量浓度和相对分子质量,可以调控微胶囊膜的厚密程度进而影响固定化酶活力。成膜液pH值依次影响壳聚糖与海藻酸盐分子中官能团的电离状态、成膜反应静电络合程度、酶蛋白包封率,最终影响固定化酶活力。在载酶量为15mg/mL,海藻酸钠质量浓度为10mg/mL,壳聚糖相对分子质量、质量浓度和pH值依次为50kDa、1mg/mL和3.0的条件下,固定化酶活力为187IU/g。     

pH对壳聚糖螯合铜(II)的螯合机理及稳定常数的影响

用紫外分光光度法研究了pH值对壳聚糖螯合Cu(II)的影响。通过显微图像、X衍射图谱及红外光谱对沉淀物进行分析。结果表明，随体系pH值增加，壳聚糖碳链上的活性基团与铜离子的螯合能力增强。溶液体系pH=5~6时，螯合物的稳定常数最大值为1.1×108；当pH接近7时，部分螯合产物析出导致稳定常数降低。酸性条件下pH值的变化对螯合物的配位比(n)无明显影响，壳聚糖–铜螯合物的配位比n=2。通过调节pH值可使溶液中壳聚糖铜螯合物析出，随pH增加，Cu2+浓度降低，当pH约为9时，Cu2+浓度达最小值1.5 mg/L。壳聚糖的主要活性基团–NH2与铜离子发生螯合，反应生成壳聚糖-铜。     

β-伴大豆球蛋白纳米粒的自组装及Vc释放行为

采用去溶剂自组装制备了β-伴大豆球蛋白纳米粒。利用浊度法研究了蛋白质量浓度、乙醇与蛋白溶液体积比、戊二醛用量对纳米粒径的影响,并测定包埋在纳米粒中Vc的释放行为。结果表明,蛋白质量浓度为10~12 g/L、乙醇与蛋白溶液体积比为4∶1、戊二醛(1.5 g/L)用量为0.5 mL时,制备的纳米粒分散性较好,纳米粒径主要分布在350~380 nm。交联纳米粒的Vc释放平稳,未交联纳米粒的Vc释放速率出现突然加速现象;Vc在pH=3.0、7.4缓冲溶液中的释放机理分别为Fickian扩散和反常输运。     

微波法羧甲基壳聚糖制备及其对Cu~(2+)吸附性能的研究

在微波辐射下,以壳聚糖为原料,研究了碱用量、氯乙酸用量、反应温度和微波加热时间四个因素对羧甲基壳聚糖制备的影响。并将其用于对废水中Cu2+的吸附,考察了不同pH,羧甲基壳聚糖的用量,振荡时间及溶液中Cu2+初始浓度对吸附性能的影响。结果表明最佳合成羧甲基壳聚糖的工艺条件为1.0g壳聚糖,6.0mL30%氢氧化钠溶液,1.4g氯乙酸,反应θ为50℃,微波加热t为20 min。当溶液pH为5.45,羧甲基壳聚糖投加量为0.03 g,振荡t为1.5 h,Cu2+初始质量浓度为300 mg/L时,在此条件下羧甲基壳聚糖对Cu2+溶液的吸附量为177.83mg/g。     

活性炭负载纳米铁的制备及其脱氯六氯乙烷的研究

纳米零价铁能够快速有效地去除多种污染物,近年受到人们的广泛重视和研究。由于纳米零价铁粒径小、比表面积大,因而易团聚,稳定性差。而且容易被空气氧化,导致活性降低。为了解决这个问题,本文首先制备活性炭负载纳米铁,然后研究活性炭负载纳米铁去除水中六氯乙烷的脱氯效果,探究了不同六氯乙烷的初始浓度、不同活性炭负载纳米铁的投放量、不同的反应时间以及不同的初始pH值对脱氯效果的影响。得出以下结论:(1)20 mL六氯乙烷溶液的起始浓度由10 mg/L增大至200 mg/L时,与12 g活性炭负载纳米铁在室温下反应40 min的氯原子脱除率先增大后减少,当六氯乙烷起始浓度等于50 mg/L,其氯原子脱除率最大,为74.73%。(2)活性炭负载纳米铁的投放量从2 g增加至16 g时,与20 mL 50 mg/L六氯乙烷反应40 min的氯原子脱除率先迅速增长后趋于平缓,投放量超过12 g后,氯原子脱除率几乎停止增长。(3)12g活性炭负载纳米铁与20mL50mg/L六氯乙烷在室温下反应,氯原子脱除率随着反应时间增加先迅速增长后趋于平缓,反应时间大于40min后,脱除率趋于平缓;同样的反应条件,溶液初始pH值处于弱酸时有利于脱氯反应,过酸或者碱性条件反而制约了六氯乙烷的脱氯效果。     

壳聚糖/活性炭纤维复合膜的制备及对甲基橙的吸附研究

通过化学交联法制备了纯壳聚糖膜和壳聚糖/活性炭纤维复合膜(质量比为1∶1.1);探讨时间、pH值、温度、甲基橙溶液初始浓度以及吸附剂用量对吸附甲基橙的影响。研究结果表明,最佳吸附时间为120 min,在pH为6.0,甲基橙初始浓度10 mg/L,温度为10℃时,膜对甲基橙的吸附效果最好,去除率达99.54%。     

交联壳聚糖对废水中Cu2+的吸附性能

以壳聚糖为原料制备交联壳聚糖吸附剂,并将其用于吸附废水中的Cu2+,考察了交联剂的用量、溶液中Cu2+初始浓度、pH、温度和时间等对交联壳聚糖吸附性能的影响。结果表明,壳聚糖与交联剂的用量比为m(壳聚糖)∶V(甲醛)∶V(戊二醛)=1.5g∶6mL∶4.5mL、溶液pH为6,溶液中Cu2+初始浓度为5mmol/L时吸附效果最佳,且吸附量随着温度升高而增加,吸附表现为吸热过程。     

植物油与水的两相溶剂体系中壳聚糖微粒的制备及抑菌性能研究

高浓度壳聚糖溶液制备得到粒径较小和均一的微粒,应用于食品的防腐与杀菌。采用壳聚糖在植物油与水的两相溶剂体系中与三聚磷酸钠(TPP)进行交联制备得到微粒,通过单因素实验确定其最适制备条件。然后通过其对大肠杆菌和金黄色葡萄球菌的杀菌实验研究其抑菌性能。当壳聚糖溶液的浓度为12 g·L-1时,可以制备得到平均粒径为(111.3±1.06)nm,PDI值为0.21±0.011。抑菌实验结果表明,当壳聚糖微粒浓度为125μg·mL-1时,壳聚糖微粒对大肠杆菌和金黄色葡萄球菌的杀菌率分别达到90.54%和91.34%。高浓度壳聚糖可以在植物油与水的两相溶剂体系中制备得到粒径较小和均一的微粒,并具有很好的杀菌活性。     

Preparation and characterization of venlafaxine hydrochloride‐loaded chitosan nanoparticles and in vitro release of drug

The venlafaxine hydrochloride (VHL)‐loaded chitosan nanoparticles were prepared by ionic gelation of chitosan (CS) using tripolyphosphate (TPP). The nanoparticles were characterized using FTIR, differential scanning calorimetry, X‐ray diffraction, dynamic light scattering, transmission electron microscopy, and X‐ray photoelectron spectroscopy. The effect of concentration of CS, polyethylene glycol (PEG), VHL and CS/TPP mass ratio on the particle size and zeta potential of nanoparticles was examined. The particle size of CS/TPP nanoparticles and VHL‐loaded CS/TPP nanoparticles was within the range of 200–400 nm with positive surface charge. In the case of VHL‐loaded nanoparticles and PEG‐coated CS/TPP nanoparticles, the particle size increases and surface charge decreases with increasing concentration of VHL and PEG. Both placebo and VHL‐loaded CS/TPP nanoparticles were observed to be spherical in nature. PEG coating on the surface of CS/TPP nanoparticles was confirmed by XPS analysis. Maximum drug entrapment efficiency (70%) was observed at 0.6 mg/mL drug concentration. In vitro drug release study at 37°C ± 0.5°C and pH 7.4 exhibited initial burst release followed by a steady release. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Taguchi orthogonal array design for the optimization of hydrogel nanoparticles for the intravenous delivery of small‐molecule drugs

In this study, a 16 runs Taguchi method was applied as an experimental design to establish the optimum conditions for hydrogel nanoparticle preparation. Five relevant factors, chitosan (CS) concentration, pentasodium tripolyphosphate (TPP) concentration, CS‐to‐TPP volume ratio, addition time of the TPP solution to the CS solution, and temperature, were selected as the main determinants, and the effects of each factor on the size of the hydrogel nanoparticles were studied at four levels. The statistical analysis revealed that the most important factors contributing to the achievement of minimum particle size were the CS‐to‐TPP volume ratio and the CS concentration. By solving a set of equations derived from the differentiation of the final model, we established the optimum conditions for hydrogel nanoparticle preparation as follows: CS concentration = 0.28% w/v, TPP concentration = 3.17% w/v, TPP/CS = 1 : 8, temperature = 25.66°C, and addition time of the TPP solution to the CS solution = 0.4 min. Also, an analysis of response at the different levels of the factors indicated that there was no remarkable interaction between them. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012     

超临界流体技术构建壳聚糖纳米粒/PLLA-PEG-PLLA 复合微粒及其表征

利用离子凝胶法和超临界强制分散悬浮液(SpEDS)技术制备具有核壳型结构的壳聚糖纳米粒(CS NPs)/聚乳酸-聚乙二醇-聚乳酸三嵌段共聚物(PLLA-PEG-PLLA)复合微粒,考察和优化了壳聚糖纳米粒和复合微粒的制备条件,并对二者的理化性质和细胞毒性进行研究。结果表明,壳聚糖纳米粒的制备优化条件为壳聚糖浓度2 mg·ml^-1、pH 5.0、三聚磷酸钠浓度1 mg·ml^-1。溶剂/非溶剂比为复合微粒粒径的显著影响因素,复合微粒的制备优化条件为油相浓度5 mg·ml^-1、水油比0.75:10.00、溶液流速2 ml·min^-1、溶剂/非溶剂比0.5:1.0。优化条件制得的复合微粒粒径为323.7 nm,透射电镜(TEM)显示其具有核壳型结构。理化表征结果显示壳聚糖与三聚磷酸钠发生作用,但制备工艺前后材料官能团未发生明显变化,而且复合微粒中PLLA-PEG-PLLA晶型更加均匀;不同浓度组的CS NPs/PLLA-PEG-PLLA复合微粒(0.25、0.50和1.00 mg·ml^-1)的细胞相对增殖率分别为105.3%、101.9%和100.9%,细胞毒性分级为0级,表明具有核壳结构的CS NPs/PLLA-PEG-PLLA复合微粒生物相容性良好,有望进一步应用于共载基因和抗癌药物的抗癌活性研究。     

Nanoparticles based on β‐conglycinin and chitosan: Self‐assembly,characterization, and drug delivery

The purpose of this study was to fabricate and evaluate nanoparticles based on β‐conglycinin (7S) and chitosan (CS) to deliver 5‐fluorouracil (5‐FU). The nanoparticles were prepared with a self‐assembly method. Turbidity measurements performed at 600 nm were used to investigate the formation of the nanoparticles as a function of the pH, 7S‐to‐CS mass ratio, and total concentration of 7S and CS. The optimum conditions for the preparation of the nanoparticles were a pH of 5.5, a 7S‐to‐CS mass ratio of 4 : 1, and total concentration of 7S and CS of 9 mg/mL. Under these conditions, the nanoparticles in solution had a high turbidity and good stability. Fourier transform infrared spectroscopy revealed that the nanoparticles were formed mainly through electrostatic interactions between the amine groups (? NH₃⁺) of CS and the carboxyl groups (? COO^?) of 7S. Scanning electron microscopy micrographs and dynamic light scattering analysis showed that the nanoparticles had an approximately spherical morphology with a smooth surface, and the mean particle size was about 120 nm with a narrow size distribution. The release of 5‐FU showed an initial burst release followed by a sustained release, and the release was pH‐dependent. The release mechanism of 5‐FU was Fickian diffusion according to the Ritger–Peppas model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41963.     

Preparation and adsorption properties of chitosan–poly(acrylic acid) nanoparticles for the removal of nickel ions

Chitosan (CS) nanoparticles with different mean sizes ranging from 100 to 195 nm were prepared by ionic gelation of CS and poly(acrylic acid) (PAA). Variations in the final solution pH value and CS : PAA volume ratio were examined systematically for their effects on nanoparticle size, intensity of surface charge, and tendency toward particle aggregation. The sorption capacity and sorption isotherms of the CS–PAA nanoparticles for nickel ions were evaluated. The parameters for the adsorption of nickel ions by the CS–PAA nanoparticles were also investigated. The CS–PAA nanoparticles could sorb nickel ions effectively. The sorption rate for nickel ions was affected significantly by the initial concentration of the solution, sorbent amount, particle size, and pH value of the solution. The samples of nanoparticles were well correlated with Langmuir's isotherm model, and the adsorption kinetics of nickel correlated well with the pseudo‐second‐order model. The maximum capacity for nickel sorption deduced from the use of the Langmuir isotherm equation was 435 mg/g, which was significantly higher than that of the micrometer‐sized CS. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

高效液相色谱法分析复配除草剂中苄嘧磺隆和丁草胺

采用反相C18柱和紫外检测器 ,对丁·苄可湿性粉剂中苄嘧磺隆和丁草胺的测定方法进行了研究。结果表明 ,以甲醇 (A)和醋酸 -醋酸钠缓冲溶液 (B ,pH =5 .6 )为流动相 ,采用梯度淋洗 :0～ 5 .5min ,A∶B =6 5∶35 (v/v) ,5 .6min后 ,改为A∶B =85∶15 (v/v) ;在波长2 5 4nm下检测 ,苄嘧磺隆和丁草胺的变异系数分别为 1.2 0 %和 0 .83% ,平均回收率分别为99.4 %和 99 9% ,苄嘧磺隆和丁草胺的浓度分别在 0 0 0 1～ 0 36 0mg/mL和 0 0 15～7 74 0mg/mL的范围内线性关系良好。方法准确、快速、重现性好 ,已用于丁·苄可湿性粉剂的质量控制。     

壳聚糖基可注射温敏凝胶的制备及其药物缓释性能研究

研究不同浓度的壳聚糖、不同质量配比的α-甘油磷酸钠和β-甘油磷酸钠混合盐和混合溶液的pH等因素对CS/GP溶液凝胶化性能的影响,在37℃形成凝胶体系负载模型药物依诺沙星考察该凝胶的释药性能。结果表明:壳聚糖浓度为100 mg,α-甘油磷酸钠和β-甘油磷酸钠按质量比为1∶4混合,控制凝胶体系pH为7.2,凝胶体系IGT可由45℃降至32℃;37℃下,可在3.5 min快速凝胶,凝胶强度达到约0.48 kPa。以依诺沙星为模型药物,载药凝胶体系可持续释放药物10 d左右,有很好的药物缓释作用。     

逆流萃取法提取甘肃棘豆中的苦马豆素

以甘肃棘豆为原料,采用φ(CH3CH2OH)=75%的乙醇为溶剂回流提取,提取液回收乙醇后用浓度为2mol/L的盐酸调节pH至3~4。离心,取上清液用氯仿以40 mL/m in流速逆流萃取,除去小极性杂质。再用浓度为2 mol/L的氢氧化钠水溶液调pH至9~10,用正丁醇以40 mL/m in流速逆流萃取。萃取液回收正丁醇后上硅胶柱分离,氯仿-甲醇-氨水洗脱,并用甲醇-氯仿重结晶得白色针状结晶,经MS和NMR鉴定确定其化学结构为苦马豆素,提取率为23 mg/kg。     

Properties of chitosan/poly(vinyl alcohol) films for drug‐controlled release

With bovine serum albumin (BSA) as a model drug, drug‐loaded films of chitosan (CS) and poly(vinyl alcohol) (PVA) were obtained by a casting/solvent evaporation method and crosslinked by tripolyphosphate (TPP). The films were characterized by FTIR, XRD, and SEM. The influential factors of drug‐loaded films on drug‐controlled release were studied. These factors included, primarily, the component ratio of CS and PVA, the loaded amount of BSA, the pH and ionic strength of the release solution, and the crosslinking time with TPP. The results showed that within 25 h, when the weight ratios of CS to PVA in the drug‐loaded films were 90 : 10, 70 : 30, 50 : 50, and 30 : 50, the cumulative release rates of BSA were 63.3, 72.9, 81.8, and 91.8%, respectively; when the amounts of model drug were 0.1, 0.2, and 0.3 g, the release rates were 100, 81.8, and 59.6%, respectively; when the pH values of the drug release medium were 1.0, 3.8, 5.4, and 7.4, the release rates reached 100, 100, 37.9, and 7.8%, respectively; the cumulative release rates of BSA were 78.4, 82.3, 84.3, and 91.7% when the ionic strengths of the release solution were, respectively, 0.1, 0.2, 0.3, and 0.4M; when the crosslinking times of these drug films in the TPP solution were 0, 5, 15, 30, and 60 min, the release rates attained 100, 100, 81.8, 65, and 43.3%, respectively. All the results indicated that the CS/PVA film was useful in drug delivery systems. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 808–813, 2005     

Optimization of Continuous Synthesis of Cross‐Linked Chitosan Nanoparticles Using Microreactors

A process for continuous synthesis of cross‐linked chitosan‐sodium tripolyphosphate (CS‐TPP) nanoparticles is optimized using microreactors for its comparison with a batch stirred reactor. The effect of various parameters including residence time, concentration of CS, pH of the CS solutions, and stabilizing surfactant concentration was modeled by population balance equations (PBEs) to determine size, growth, and nucleation rates of the CS‐TPP nanoparticles. The smallest particle size was obtained at lower residence time, lower concentration of CS, pH 5, and using a surfactant concentration above its critical micellar concentration. The particles obtained from the microreactors are agglomerated but are smaller in size as compared to those obtained from the batch reactor. The system was also optimized for the minimum particle size applying the estimated growth rate and the PBEs.