壳聚糖-脱氧胆酸及其叶酸偶联体的表征及自组装特性研究

以1-乙基-(3-二甲基氨基丙基)碳酰二亚胺(EDC)为催化剂,将脱氧胆酸接枝到壳聚糖主链的氨基上,得到疏水改性的双亲性壳聚糖;再将叶酸连接于壳聚糖氨基,可得到具有肿瘤靶向潜力的双亲性共聚物.利用红外光谱、1H核磁、X射线晶体衍射图谱对其结构进行表征.脱氧胆酸-壳聚糖、叶酸-壳聚糖-脱氧胆酸在水相中通过透析处理均能形成自聚集体,利用荧光探针技术研究其自聚集行为.制得的两种自聚集体均具有较低的临界胶束浓度(10-2mg/ml),透射电镜和粒径分析测试显示制得的自聚集体为纳米级颗粒.随着脱氧胆酸取代度的增加,粒径降低,临界胶束浓度下降,但叶酸直接偶联壳聚糖导致自组装阻力增加.     

巯基化壳聚糖衍生物自组装纳米球的制备与表征

以N-羟基琥珀酰亚胺(NHS)和1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC·HCl)为催化剂,将制备的双羧基聚乙二醇(COOH-PEGCOOH)和部分巯基化聚乙烯亚胺(PEI-SHx)先后接枝于壳聚糖分子,得到巯基化壳聚糖衍生物(CS-PEGPEI)。利用傅立叶红外光谱仪(FT-IR)和核磁共振仪(1 H NMR)对其结构进行表征;通过透析法制备自聚集纳米粒,透射电子显微镜(TEM)和动态激光粒度分析仪(DLLS)分析测试自聚集纳米粒显示,自聚集纳米粒为球状纳米胶束,该纳米球有望成为纳米药物及基因的载体。     

两亲嵌段自组装模板法制备结构可控纳米杂化材料

以窄分布两亲嵌段共聚物MPEG-b-PS在甲苯中自组装形成的反胶束为纳米模板制备了银纳米杂化材料;通过TEM、UV对杂化材料的形貌和结构进行了分析,研究了还原剂水合肼用量对银纳米粒子尺寸的影响,结果表明,银纳米粒子尺寸随着还原剂用量的增加而增大,当水合肼用量分别为溶液质量的0.5%、1.0%、2.0%、5.0%时,相应得到的银纳米粒子尺寸分别为3～4nm、7～8nm、10～12nm、20nm,说明通过调整还原剂用量可控制纳米杂化材料的尺寸.     

两亲嵌段共聚物的合成及纳米自组装

首先用苄氧羰基赖氨酸和三光气反应合成苄氧羰基赖氨酸酸酐,然后将聚乙二醇中活性较弱的羟基转化为氨基,最后以双端氨基聚乙二醇作为引发剂,采用阴离子开环聚合合成了聚(Nε-苄氧羰基赖氨酸)-聚乙二醇-聚(Nε-苄氧羰基赖氨酸)(PLL(Z)-PEG-PLL(Z))。PLL(Z)-PEG-PLL(Z)经去保护后得到带正电荷的聚赖氨酸-聚乙二醇-聚赖氨酸(PLL-PEG-PLL)。PLL(Z)-PEG-PLL(Z)在水溶液中自组装形成的聚集体类似于纳米多孔聚集体结构,具有疏松的空洞,原子力显微镜观测其呈球形,其大小为220 nm左右。     

塑性变形诱发表面自纳米化的研究及其应用

详细介绍了强烈塑性变形诱发表面自纳米化的研究进展,即形变诱发表面自纳米化的方法与设备、表面自纳米化层的结构及其表征、形变诱发表面自纳米化的机理及其相关应用,并展望了形变诱发表面自纳米化的研究与应用.     

自组装合成表面包覆壳聚糖的碳微球

采用静电自组装实现了壳聚糖(CS)对碳微球(CMSs)的包覆。将化学气相沉积法制得的CMSs用HNO3和H2O2混合溶液进行表面氧化修饰,引入含氧官能团,使其表面带负电,通过静电作用力与带正电的CS自组装,从而改变了CMSs的表面活性。利用场发射扫描电子显微镜、傅立叶红外光谱仪、X-射线衍射仪及热重分析仪等检测手段表征了产物的形貌和结构特征。结果表明:CS成功地组装到CMSs表面,当CMSs与CS的质量比为1∶2时,CS均匀覆盖于CMSs表面,而且在水溶液和乙醇中的分散性较好。     

自组装的壳聚糖/SiO2杂化膜

以硅溶胶为晶种,使硅酸钠在壳聚糖膜中自组装形成SiO2微粒和晶须,并得到壳聚糖/SiO2杂化膜(以下简称杂化膜).用电子扫描电镜观察了SiO2微粒和晶须的形貌,研究杂化膜在水中的溶胀率,杂化膜的拉伸强度、伸长率和弹性模量等力学性能,杂化膜的热稳定性能.结果表明:杂化膜内SiO2为长3.0～6.0 μm,宽150m的晶须,以及直径为3.0μm的微粒;当膜内SiO2质量分数为7.5%时,杂化膜的力学性能达到最佳,其拉伸强度、弹性模量和断裂伸长率分别为38.39MPa、2383.02MPa、19.82%;随着杂化膜内SiO2质量分数从2.5%增加到12.5%,其溶胀率从112.0%下降到83.7%;杂化膜在200～800 nm波长范围的吸光度也逐渐降低;杂化膜的分解温度为314℃,高于单纯壳聚糖膜的分解温度290℃,表明SiO2晶须与壳聚糖杂化可提高壳聚糖膜的热稳定性.     

多相材料的自蔓延高温合成和致密化

自蔓延高温合成技术(SHS)是制备材料的重要手段。但由于该过程中强烈的杂质释放及急剧的温度变化,合成产品多为疏松状态。要制备密实多相材料还必须与其他的致密化工艺相配合。本文介绍了常与之相配合的致密化工艺及所适应的多相材料,并报告了一些材料的某些力学性能。     

碳纳米管/壳聚糖载体的静电自组装及其表征

采用混酸氧化法制备表面带负电的羧基化碳纳米管分散体系,以叶酸靶向受体改性壳聚糖,通过羧基化碳纳米管与叶酸改性壳聚糖进行静电自组装,制备了生物相容性好、肿瘤靶向性高的碳纳米管/壳聚糖药物复合载体材料(FA/CS-SWCNTs).利用FTIR、XPS、SEM和TG等分析方法对相应产物的形貌和结构进行了研究.实验结果表明叶酸改性壳聚糖成功组装到羧基化碳纳米管上,热重分析显示该复合材料中壳聚糖的质量分数达到35％,其中叶酸在壳聚糖上的偶联率为8.1％,该载体材料具有良好的亲水性、安全性和靶向性等优点,有望成为新型的肿瘤靶向功能载体材料.     

金属材料表面自纳米化及其研究现状

文章综述了材料表面自纳米化的国内外研究现状,包括表面自纳米化的制备方法、基本原理、表层结构及机理、性能研究,展望了表面自纳米化技术的发展前景及目前有待解决的问题。     

壳聚糖修饰银纳米颗粒的制备及抗菌性能研究

采用液相化学还原法,以壳聚糖为修饰剂,硼氢化钠为还原剂,制备了壳聚糖修饰银纳米颗粒(chitosan-Ag NPs)。通过X射线粉末衍射仪、透射电子显微镜、傅立叶变换红外光谱仪等对所制备样品的结构和形貌进行了表征。结果表明,所制备纳米颗粒具有面心立方Ag的晶型结构,壳聚糖通过氨基和羟基中的N、O原子与Ag+的化学键合作用修饰在纳米颗粒表面,起到了限制颗粒粒径长大和防止其团聚的作用。采用肉汤连续稀释法检测了样品对大肠杆菌和金黄色葡萄球菌的抑菌杀菌性能,结果表明chitosan-Ag NPs具有优异的抗菌性,抗菌性能受到粒径大小的影响。     

Elevated anti-inflammatory effects of eicosapentaenoic acid based self-aggregated glycol chitosan nanoparticles

The formation of nanoparticles from eicosapentaenoic acid (EPA) is crucial to improving EPA's bioavailability and pharmacological properties, and widening its use in biomedical fields. In this study, we report EPA-conjugated glycol chitosan (GC) that can self-aggregate into core-shell nanoparticles. The EPA-GC nanoparticles were internalized into the cytosol of RAW 264.7 cells by endocytosis, which results in effective delivery of EPA to the cells. There were no differences in the cell viability after the treatment with EPA-GC nanoparticles. In the anti-inflammatory studies, the EPA-GC nanoparticles significantly inhibited lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and interleukin-1 beta (IL-1 beta) secretion in RAW 264.7 cells. The anti-inflammatory effects of the EPA-GC nanoparticles were far better than those seen for EPA only. Given their excellent bio-physicochemical properties, it is expected that EPA-GC nanoparticles may have a potential for widening the use of EPA in biomedical fields and, in particular, the treatment of inflammatory diseases.     

甘草酸羧甲基壳聚糖纳米粒的制备及其性能研究

通过正交试验设计优化钙离子交联法制备羧甲基壳聚糖纳米粒工艺条件,以透射电镜观察,纳米粒外观形态圆整;以激光粒度分析仪测定,纳米粒平均粒径为(131.2±5.27)nm;以高效液相色谱法测定,纳米粒包封率为(51.2±0.41)%,载药量为(16.7±0.29)%。对模型药物甘草酸的体外释放性能考察结果表明,所制备的纳米粒具有较好的控制药物释放的作用。     

Preparation and characterization of self-assemblied nanoparticles based on folic acid modified carboxymethyl chitosan

Folate (FA) modified carboxymethyl chitosan (FCC) has been synthesized and the hydrogel nanoparticles can be prepared after the sonication. Formation and characteristics of nanoparticles of FCC were studied by fluorescence spectroscopy and dynamic light scattering methods. The critical aggregation concentration value of FCC in water was 9.34 × 10⁻² mg/ml and the mean hydrodynamic diameter of particle was 267.8 nm. The morphology of nanoparticles was observed by transmission electron microscopy which had spherical shape. Loading capacity (LC), loading efficiency (LE) and the in vitro release profiles of nanoparticles were investigated by doxorubicin (DOX) as a model drug. When the initially added amount of DOX versus the constant amount of FCC polymer was increased, the LC in the nanoparticles was gradually increased and the LE decreased. The in vitro release profile of the DOX from the FCC nanoparticles exhibited sustained release. Cellular uptake of FCC nanoparticles was found to be higher than that of nanoparticles based on linoleic acid (LA) modified carboxymethyl chitosan because of the FA-receptor-mediated endocytosis, thereby providing higher cytotoxicity against Hela cells.     

Preparation and evaluation of N-caproyl chitosan nanoparticles surface modified with glycyrrhizin for hepatocyte targeting

Background: The development of an efficient targeted drug delivery system into cells is an important subject for the advancement of drug carriers. In this study, a novel hepatocyte-targeted delivery system with glycyrrhizin (GL) surface modification based on N-caproyl chitosan (CCS) has been developed. Method: CCS was synthesized by acylation of amino group of chitosan, and GL was oxidized to be conjugated to the surface of N-caproyl chitosan nanoparticles (CCS-NPs-GL). The synthesized nanoparticles were first characterized for their morphology, particle size, zeta potential, in vitro stability in plasma, tissue distribution, and hepatocyte-targeting uptake in vivo. Results: The obtained results showed that the spherical and discrete nanoparticles prepared with oxidized GL/CCS ratio of 0.14:1 (w/w) exhibited a positive electrical charge and associated adriamycin quite efficiently (association efficiency: 87.5%). The prepared nanoparticles also possessed dimensional and GL surface-binding stability and slow release property in plasma in vitro. The biodistribution of these particles after intravenous injections in mice revealed accumulating drug concentrations in the liver, spleen, and lungs while decreasing drug concentrations in the heart and kidney. The content of adriamycin-loaded CCS-NPs-GL in the liver was 1.6 times higher than that of non-GL-modified CCS-NPs. Furthermore, in vivo uptake of CCS-NPs-GL by rat hepatocytes showed 2.1 times higher nanoparticle uptake compared with non-GL-modified CCS-NPs, which suggested that CCS-NPs-GL were preferentially distributed in hepatocytes by a ligand–receptor interaction. Conclusion: This article indicated that CCS-NPs-GL was a stable and effective drug delivery vehicle for hepatocyte targeting.     

O-羧甲基化壳聚糖修饰磁性Fe3O4纳米粒子及其生物应用

采用共沉淀法制备Fe3O4纳米粒子,用XRD测定粒子成分,用透射电镜和显微镜观测粒子形貌,用震动样品磁场计测定Fe3O4粉末饱和磁化强度,再以O-羧甲基化壳聚糖修饰后,用红外光谱检测粒子成分.粒子性能良好,能很好的应用于生物分离,连接等.     

壳聚糖修饰氧化铁磁性纳米颗粒的制备和性能研究

通过共沉淀法制备氧化铁磁性纳米颗粒,用壳聚糖对其表面进行修饰得到样品(CS@MNPs);表征其形貌结构、尺寸、表面基团、表面电荷、磁学性质和在不同介质中的稳定性等。实验结果表明,CS@MNPs具有典型的立方反尖晶石晶体结构;粒径为16.5nm;在生理(pH值7.4)条件下拥有较高的正电荷(10mV);呈现超顺磁性,对驰豫时间T1、T2,尤其是T2*具有很强的响应;在双蒸馏水和含10%新生牛血清的RPMI 1640培养液中具有良好的稳定性,具有作为磁共振造影剂的潜力。     

生物素化普鲁兰多糖纳米颗粒制备与表征

合成生物素化普鲁兰多糖衍生物(BP),采用纳米沉淀法制备纳米颗粒(BPNs),考察制备条件对纳米颗粒性质影响,为进一步将其作为药物载体的研究提供基础.通过酯化反应将生物素羧基与普鲁兰多糖连接,生成的衍生物BP通过FI-IR和1H-NMR表征,取代度采用电感耦合等离子体光谱仪(ICP)确定;BPNs进行透射电镜、动态光散射仪和ζ电位仪表征与检测,颗粒表面生物素采用Quant*TagTM Biotin Kit生物素测定试剂盒测定.获得取代度21(BP1),46(BP2),81(BP3)3种衍生物,其中BP2和BP3能够制备纳米颗粒(LBPNs,HBPNs).纳米颗粒呈球形,表面光滑规整,平均粒径100～300nm,水中ζ电位在一17mV左右.制备过程中,粒径随BP浓度(10～50mg/ml)增加而增加((136.2±46.8)nm,(190.8±89.6)nm和(254.5±140.0)nm).调整水相组成为水:元水乙醇(v/v)1:1和1:2时粒径分别为(170.7±30.4)nm和(158.8±21.0)nm.HBPNs和LBPNs表面的生物素量为衍生物的(1.9±0.03)%和(2.0±0.04)%.生物素化普鲁兰多糖衍生物通过纳米沉淀法能制备出纳米颗粒,颗粒表面存在有生物素,颗粒性质受制备条件影响.     

Preparation and in vitro characteristics of lactoferrin-loaded chitosan microparticles

In order to achieve the delivery and controlled release of lactoferrin (LF), a biologically multifunctional protein, chitosan microparticles loaded with LF were prepared. Several types of chitosan microparticles containing LF were prepared by the w/o emulsification-solvent evaporation method, and the particle characteristics and release properties in JP 2nd fluid, pH 6.8, were examined. All kinds of microparticles were obtained at a yield of more than 75% (w/w). LF-loaded microparticles prepared by nonsonication and nonaddition of sulfate, named Ch-LF(N), showed high drug content, small particle size and spherical particle shape. Also, for release properties, Ch-LF(N) exhibited gradual drug release over 7 hr with less remaining in the microparticles. Considering the mucoadhesive properties of chitosan microparticles, Ch-LF(N) are suggested to be useful for gradual supply to topical diseased sites or for effective delivery to intestinal areas with abundant LF receptors.