温敏性聚合物胶束应用于药物控制释放体系的研究进展

当环境温度发生变化时,温敏性双亲嵌段聚合物对这一刺激产生响应,自组装为具有疏水性核/亲水性壳结构的胶束,可作为载体负载活性物质或疏水性药物,具有提高药物利用率、靶向作用、降低毒副作用等特点,可应用于药物控制释放等生物医药领域,具有显著的研究价值和应用前景。介绍了不同类型温敏性聚合物胶束在药物控制释放体系的研究进展。     

药物控制释放研究及应用

药物控制释放是目前药物学、高分子生物学等多个领域发展的交叉学科。本文主要介绍了药物控制释放体系的种类、机理及高分子材料，并着重介绍了药物控制释放技术在医药上的应用发展现状。     

两亲性嵌段共聚物胶束的制备及对药物的控制释放

两亲性嵌段共聚物在水溶液中通过自组装可以形成以疏水嵌段为核,以亲水嵌段为壳的胶束。其亲水嵌段对胶束起稳定和保护作用,在胶束中通过物理、化学方式载入药物,可以实现对药物的控制释放。简述了嵌段共聚物胶束化的一些基本途径,如利用氢键,离子间相互作用,改变温度,自由基共聚,改变外部环境pH等,探讨了其对模型药物的控制释放。     

控制药物释放体系

介绍了控制释放技术的特点,系统地讲述了控制药物释放的各种体系,并展望了控制释放技术的发展前景。     

含咔唑基聚合物的合成、发光性能及应用

采用封管聚合法合成了3种含咔唑基聚合物——聚乙烯基咔唑(PVK)、聚2-(9-咔唑基)乙基甲基丙烯酸酯(PCEM)和聚N-〔3-(9-乙基咔唑基)〕甲基丙烯酰胺(PECMA),考察了其紫外光谱和荧光光谱,探讨了取代基对咔唑基团发光性能的影响。结果表明,单体CEM和ECMA表现出明显的结构自猝灭效应(SSQE),而相应的聚合物未见SSQE。单体乙烯基咔唑(NVK)、CEM的荧光最大发射波长分别为440、435 nm,相对于咔唑(418nm)有明显的红移,ECMA则蓝移(410 nm),而相应的聚合物红移或蓝移都不明显。将聚合物作为空穴传输材料,通过共聚引入8-羟基喹啉铝高分子后,8-羟基喹啉铝高分子发光材料的电致发光起亮电压由14 V下降至9V,发光效率提高了3~4倍。     

含糖聚合物在药物释放应用中的新进展

含糖聚合物因其优良的亲水性和生物相容性成为近期研究的热点,并且被广泛应用于生物医药领域。综述了含糖聚合物作为药物缓释载体应用的新进展。     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-（4-（9-咔唑）苯乙炔基）芘和1,6-二（4-（9-咔唑）苯乙炔基）芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

微凝胶在药物控制释放系统中的应用

药物控制释放系统能弥补传统给药方式在人体血药浓度、药效等方面的不足,并在控制药物释放速率的同时,保持药物有效浓度、降低毒副作用。本文在介绍该释药系统的基础上,以微凝胶结合具体实例阐述说明系统的应用原理及效果,研究发现微凝胶对模型药物具有控制释放作用。     

新型自组装胶束的制备及其药物释放性能的研究

设计并合成了由亲水链段与疏水链段所组成的新型两亲星形嵌段共聚物.在水溶液中,该星形共聚物能够自组装形成具有核壳结构的纳米胶束粒子.当环境的pH分别为5、7.4、9时,共聚物胶束相应的低临界溶液温度(IESF)分别为32.0、36.6、39.5℃.由于亲水链段具有的温度和pH双响应特性,载药的自组装共聚物胶束也显示出了温度和pH双重响应的药物释放行为.     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-[4-(9-咔唑)苯乙炔基]芘和1,6-二[4-(9-咔唑)苯乙炔基]芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

Elastic Polymeric Network Structure for Slow Release Drug Delivery Systems

Network structures based on poly(lactic acid)(PLA) were prepared for use as drug carriers to improve the effectiveness of drug therapy. A prepolymer precursor, with low molecular weight (5148), as determined by Gel Permeation Chromatography (GPC), was prepared by polycondensation of poly(lactic acid) with hydrolyzed ?-caprolactone. A second step that is necessary to increase the molecular weight and build up a network structure with elastic properties involved further polycondensation with stoichiometric amount of 1,6-hexamethylene diisocyanate to finally obtain Poly(ester urethane) with a molecular weight of 25680. The physicomechanical properties of the resulting polymeric networks were evaluated and the one that found to exhibit the best combination of tensile strength (3.83 MPa) and elongation at break (646%) was selected for slow release applications. Propolis and Doxorubicin as bioactive materials were incorporated into the selected sample and shaped in the form of circular discs with 0.9 cm diameter and 0.4 cm thickness. The discs containing the bioactive materials were subjected to a buffer solution at pH 7.4, and the release rates of Propolis and Doxorubicin were measured spectrophotometrically and found to be 35 µg/L/day and 70 µg/L/day for Propolis and Doxorubicin, respectively over a prolonged time of 15 days.     

甲基丙烯酸-丙烯酰胺共聚水凝胶的药物释放动力学研究

以甲基丙烯酸、丙烯酰胺为原料,合成了pH敏感甲基丙烯酸-丙烯酰胺共聚水凝胶,研究其牛血清白蛋白释放动力学和释放机理,结果表明:牛血清白蛋白释放具有较好的pH依赖性,丙烯酰胺或交联剂用量的增加,牛血清白蛋白释放量降低;pH 1.0时释放机理为Fickian扩散,pH 6.8时释放机理为非Fickian扩散。     

Charge-Conversional Binary Drug Delivery Polymeric Micelles for Combined Chemotherapy of Cervical Cancer

Candesartan-g-polyethyleneimine-cis-1,2-cyclohexanedicarboxylic anhydride (CD-g-PEI-HHPA, CPH) polymer-drug conjugates based on charge-conversional delivery, enhanced buffering capacity, amidase-triggered drug release, and combined cancer chemotherapy strategies were successfully synthesized for simultaneous and effective codelivery of CD and paclitaxel (PTX) to treat cervical cancer. The CPH polymer-drug conjugates could self-assemble into core-shell structure micelle of around 100 nm in diameter with negative surface charge and were employed to load PTX to formulate binary drug delivery system. The CPH polymeric micelles could mediate quick endosomal escape and amidase-responsive drug-release manners. In vitro cytotoxicity and in vivo investigations confirmed CPH binary drug delivery system exerted strong antitumor efficacy.     

A Model of Controlled Release of Polymer-dispersed Drug Systems Containing Regulatory Particles

Abstract

A model of controlled release systems using a polymer matrix with mixtures of dispersed drug particles and regulatory particles is considered. The regulatory particles are fillers that release at a slower rate than the drug and open more paths for the passage of the drug. Mathematical analysis shows that both the drug and regulatory particles have Fickian diffusion behaviors. The use of regulatory particles increases the release rate and can make the system responsive to physiological change.     

8-羟基喹哪啶螯合树脂对Cr~（6＋）的吸附性能研究

研究了8-羟基喹哪啶螯合树脂（PS-HQD）在HAc-NaAc体系中对铬离子的吸附性能。结果表明,该树脂吸附Cr6＋的最佳pH为5.0,树脂吸附的平衡时间为8 h,吸附容量9.68 mg/g。表观速率常数k298=1.87×10^-4s^-1,一次洗脱回收率达94.3%。吸附过程符合Langmuir和Freundlich模型。     

奈非西坦的合成研究

奈非西坦是新研制的一种对阿尔茨海默氏病和脑血管后遗症有良好的临床治疗价值的药物。对奈非西坦的各种合成方法进行了总结,分析了各路线的优缺点,并对奈非西坦的药理学内容做了概述。     

新烟碱类杀虫剂呋虫胺的合成新工艺

在调研国内外有关呋虫胺研究文献的基础上,通过反复实验,找到了合成呋虫胺的新工艺.。以1,4-丁内酯计总收率达到36%。通过正交试验对各步骤反应进行了优化,确定了最佳反应条件。相比其它方法,本工艺合成呋虫胺具有成本低、步骤少、三废少、规模化生产可行性高等优点。     

一种树脂包膜尿素养分速测的方法及其评价

缓释肥料国家标准(GB/T23348-2009)中规定用25℃静水浸提凯氏定氮法测定肥料氮素释放率;但该法浸提的周期较长,且相对繁琐耗时。提出100℃快速浸提和用对二甲氨基苯甲醛分光光度法测氮,分别用该法与25℃静水浸提凯氏定氮法测定了2种典型树脂包膜尿素的氮素释放率,结果表明,两种方法测定结果之间的相关性极显著,R2分别达1和0.9997。100℃浸提用对二甲氨基苯甲醛分光光度法可以准确地预测树脂包膜尿素25℃浸提凯氏定氮法测氮的养分释放率和养分释放期。     

包膜尿素总氮含量测定方法的改进

采用经典的凯氏定氮法[1]对包膜型控释尿素总氮含量的测定,试样需经过消解、蒸馏、滴定三个操作步骤。该方法分析人员在操作过程中稍有不慎易导致误差,分析速度慢。改用KDY-9830型凯氏定氮仪法可减少或避免分析人员操作误差,分析速度较快。用该方法测定包模型控释尿素样品中总含氮量与用国标法(GB/T23348—2009)测定的相比,结果相差小于0.5%。KDY-9830型凯氏定氮仪法较经典的凯氏定氮法操作简便、快速、导致误差的几率少,测定数据稳定可靠,且可进行大批量样品的测定。     

Functionalization of carbon nanomaterials for advanced polymer nanocomposites: A comparison study between CNT and graphene

The allotropes of carbon nanomaterials (carbon nanotubes, graphene) are the most unique and promising substances of the last decade. Due to their nanoscale diameter and high aspect ratio, a small amount of these nanomaterials can produce a dramatic improvement in the properties of their composite materials. Although carbon nanotubes (CNTs) and graphene exhibit numerous extraordinary properties, their reported commercialization is still limited due to their bundle and layer forming behavior. Functionalization of CNTs and graphene is essential for achieving their outstanding mechanical, electrical and biological functions and enhancing their dispersion in polymer matrices. A considerable portion of the recent publications on CNTs and graphene have focused on enhancing their dispersion and solubilization using covalent and non-covalent functionalization methods. This review article collectively introduces a variety of reactions (e.g. click chemistry, radical polymerization, electrochemical polymerization, dendritic polymers, block copolymers, etc.) for functionalization of CNTs and graphene and fabrication of their polymer nanocomposites. A critical comparison between CNTs and graphene has focused on the significance of different functionalization approaches on their composite properties. In particular, the mechanical, electrical, and thermal behaviors of functionalized nanomaterials as well as their importance in the preparation of advanced hybrid materials for structures, solar cells, fuel cells, supercapacitors, drug delivery, etc. have been discussed thoroughly.