含阿斯匹林的丙烯酸酯共聚物及其水解

<正> 阿斯匹林是近年来发现具有抗血小板凝聚效应的普通药物。在酯基上含有阿斯匹林基团的亲水性丙烯酸酯聚合物的水解研究表明,这些聚合物有可能作为控制释放阿斯匹林的生物相容性释放体系。本文合成了甲基丙烯酸β-(乙酰水扬酰氧)乙酯(HEMAASA)与甲基丙烯酸(MA)的共聚物,观察其水解行为,以期寻找能够进一步控制释放阿     

生物可降解聚酯用作蛋白质药物控释载体

聚乳酸PLA及乳酸与羟基乙酸的共聚物PLGA,由于其良好的生物相容性以及生物降解性,可用作蛋白质类药物控释体系的载体材料,同时可延长蛋白质药物的释放.本文综述了几种生物相容性聚酯及其衍生物以及它们的形成方法:(1)在PLGA的分子链中引入亲水性的含醚键的分子如PEO、PEG,来提高聚合物的亲水性,形成PLGA嵌段共聚物;(2)将细胞可接受的片段或多肽固定在聚合物支架表面,来增强PLGA与细胞间的粘附力,得到靶向的PLGA衍生物;(3)改变PLGA载体内的酸性环境,提高蛋白质药物在载体中的稳定性,发展了支化聚酯PVA-g-PLGA,并得到均速的药物释放.以上这些方法所得到的聚酯及其衍生物,均可作为蛋白质类药物安全、可靠的载体材料.     

NIR触发的两亲性含糖聚合物修饰的纳米金棒的制备及应用

通过配体交换的方法成功将含糖聚合物PGAMA14-PCL32-SH接枝到纳米金棒的表面(Gly@AuNRs).借助X-射线光电子能谱(XPS)、动态光散射(DLS)、热重分析(TGA)等对Gly@AuNRs进行了表征.为了得到药物控释所需要的合适的实验条件,研究了近红外光照射下Gly@AuNRs在水溶液中的光热转换行为.用Gly@AuNRs包裹药物姜黄素(CUR),研究了药物的体外释放,发现近红外光能有效控制药物的体外释放.细胞实验结果表明含糖聚合物的接枝大大提高了纳米金棒的生物相容性.因此,Gly@AuNRs复合材料能够作为生物相容性载体材料,并实现近红外光触发的药物的可控释放.     

聚己内酯在药物载体方面的研究进展

聚己内酯(poly-ε-caprolactone,PCL)是一种人工合成的聚酯类高分子材料,对人体无毒,具有良好的生物相容性、生物可降解性和无免疫原性。PCL还对其它聚合物具有良好的相容性,可以制备出多种性能优良的共聚物或共混物,因此PCL及其共聚物、共混物作为药物载体的研究受到国内外研究者的高度重视。此外,PCL因其在人体中的降解过程十分缓慢可作为药物控释材料,目前已经获得美国FDA的批准。本文将从聚己内酯的合成与改性及其各剂型在药物载体方面的研究进展进行综述。     

氨基酸酯-烷基醚混合取代聚膦腈的合成与表征

聚膦腈高聚物,因其良好的生物相容性而用作生物医用材料。若在其侧链引入对热(如烷氧基醚)或对pH值敏感和可生物降解的基团(如氨基酸酯),则可得到具有环境敏感性和可生物降解性能的高聚物,这些高聚物可望作为药物载体,用于药物的控制释放。     

纳米金属有机骨架材料及其载药应用

金属有机骨架材料(MOFs)是指由含氮、氧等多齿有机配体与金属离子通过自组装形成的配位聚合物。由于金属有机骨架材料的大比表面积和高孔隙率等优点使其在药物负载领域有广泛应用。近年来,纳米金属有机骨架材料(NMOFs)因既具有MOFs的特点,又具有纳米材料独特的理化性能,使其兼具药物负载量高、目标靶向性好、表面易改性和生物相容性优良等特点,已成为一种优异的纳米级载药系统。本文介绍了NMOFs的常用制备方法,主要包括溶剂热法、反相微乳液法与超声波法,并对其优缺点进行了讨论;详细阐述了载药NMOFs的特性及其不同类型对于各类药物的负载能力;指出今后其主要的研究方向是改善生物相容性、实现更有效的表面功能化、扩展生物NMOFs及其负载药物的种类,使其应用到更多疾病的治疗上。     

生物可降解超支化聚合物的研究进展

近年来,随着聚合物材料和生物医药交叉领域的发展,生物可降解聚合物得到了广泛关注.其中,生物可降解超支化聚合物具有独特的三维拓扑结构、大的内部空腔、众多的活性末端基团以及良好生物相容性和可降解性等特点,在生物医学领域包括药物/造影剂输送、基因转染、蛋白质纯化/检测/输送、抗菌、组织工程等领域都展现出很大的应用前景.本文主要从水解、酶解和刺激降解的降解机理出发,详细综述了近年来生物可降解超支化聚合物的研究进展,并简单介绍了它们在疾病治疗中的应用.     

基于生物大分子的纳米药物载体

生物大分子材料由于其可再生性、无毒性以及良好的生物相容性、生物可降解性和黏膜粘附性等特点成为药物载体研究的热点,尤其是将其作为纳米药物载体材料更加受人关注。本文首先对生物大分子纳米颗粒常用的制备方法--乳化法、自组装法和离子凝聚法进行了详细的介绍。由于乳化法在一定程度上破坏了生物大分子的生物相容性,因此自组装法和离子凝聚法是比较理想的制备方法。其中自组装法是利用两亲性的生物大分子,如蛋白质、多糖衍生物等在静电作用、疏水作用、范德华力等非键合作用力下组装成纳米结构;而离子凝聚法则是利用聚电解质与带相反电荷物质之间的静电作用形成纳米结构。接着本文对通过这些方法获得的生物大分子纳米颗粒作为蛋白类药物、抗癌药物以及基因药物的载体在近年来的研究进展进行了归纳和总结,结果显示其在药物缓释体系中具有广阔的应用前景。     

生物分子响应性高分子材料

在智能高分子材料中,生物分子响应性高分子能够在糖类、多肽和酶等生物分子的刺激下发生宏观性质(如:体积、表面浸润性和硬度等)的大幅转变。生物分子响应性聚合物材料包括水凝胶、共聚物膜等类型,一般通过与生物分子间的氢键、分子间作用力等弱相互作用实现响应过程,在组织工程、功能材料、生物传感、药物可控释放等领域有广泛应用前景,吸引了大量科研人员的关注。与传统外源性刺激(温度、pH、光等)相比,生物分子作为刺激源的智能高分子材料具有更好的靶向性和生物相容性,能满足生物医用材料在人体内的应用,可以作为开发新一代精准药物的靶向释放平台。本文分别对糖类、蛋白、酶和DNA四类生物分子响应性高分子材料的结构设计、响应机制及相关应用进行概述,并对生物分子响应性高分子的发展方向作了展望。     

用于基因和药物传递的多肽及聚多肽材料

多肽和聚多肽作为一类新型的生物医用材料,由于其具有良好的生物活性、生物可降解性以及生物相容性而备受瞩目.将具有特殊生理功能的多肽作为基因或药物载体、或用于药物修饰等,可以提高基因转染效率,增强药物的靶向治疗效果,降低药物的毒副作用.本文综述了近年来多肽及聚多肽材料在这些生物医学领域的应用及进展,对部分活性肽的作用机制和...     

SYNTHESIS OF 1-(ACETYLSALICYLYL)-BENZOTRIAZOLE AND ITS REACTION WITH POLYVINYL ALCOHOL

l-(Acetylsalicylyl)-benzotriazole, a new active amide of acetylsalicylic acid has been synthesized either from acetylsalicylic acid and benzotriazole using DCCI as condensation agent or via acetylsalicylyl chloride and benzotriazole in the presence of triethylamine. The obtained active amide reacted readily with the hydroxyl group of PVA to produce the acetylsalicylyl ester of PVA.     

聚乙烯醇载体的研究 Ⅲ.由聚乙烯醇衍生的活性酰胺和活性酯及其作为亲合色谱载体的应用

<正> 亲合色谱法在现代生物学和医学上作为新的得力分离分析手段而方兴未艾。合色谱法是将相互在生物学上具有特异亲合力的某一化合物作为固定相接在水不溶性载体上,利用对此固定相的亲合力的差异以分离提纯另一化合物为目的的方法。常用的水不溶性载体如天然纤维素,葡聚糖凝胶,琼脂糖凝胶等或因成型不易,或因对酸,霉菌等的不     

STUDIES ON POLYVINYL ALCOHOL CARRIERS Ⅲ. ACTIVE AMIDES AND ESTERS DERIVED FROM POLYVINYL ALCOHOL AND THEIR APPLICATION IN AFFINITY CHROMATOGRAPHY

Polyvinyl alcohol carriers bearing active amide and active ester groups were prepared by acetaliza-tion of granular macro-reticular water-insolub1e PVA with glyoxylic acid or p-formylbenzoic acidand further activation reaction with benzotriazole or N-hydroxysuccinimide using DCCI as con-densation agent. The active amides or active esters obtained were easy to react with amines suchas n-butylamine or proteins under mild condition. Ovomucoid, an inhibitor of trypsin was immo-bilized on the above-obtained reactive PVA carrier to give effective affinity adsorbent for the separa-tion or purification of trypsin.     

A Novel Route to N-Styrylamides

A general synthesis of N-styrylamides starting from amides and phenylacetaldehyde is described. Condensation of the amide, aldehyde and benzotriazole affords N-(1-benzotriazol-l-yl-2-phenylethyl)amides 2 from which the benzotriazole molecule is smoothly eliminated.     

Detection of DNA probes using Diels Alder cycloaddition and SERRS

A number of methods for detecting specific DNA sequences have been used to provide data for use in diagnosis of disease states and examination of gene expression. This study shows how the use of labelled oligonucleotides created by Diels Alder cycloaddition can be used as surface enhanced resonance Raman scattering (SERRS) active probes that provide easily identifiable signals at low concentrations in a mixture. The probes were produced by first tagging the oligonucleotides with a furan residue at the 5'-terminus to act as the diene. Three specifically designed benzotriazole azo maleimide dyes were then used as dienophiles to undergo cycloaddition with the furan modified oligonucleotide to generate SERRS active probes. These probes gave excellent SERRS signals from a silver-PVA film. Surface mapping of the silver PVA film indicated that the distribution of the dyes was uniform and that the number of moles of probe detected at any one time was approximately in the attomole region.     

Synthesis of polyesters containing nucleic acid base derivatives as pending side chains

Preparations of four diol monomers containing nucleic acid bases and the corresponding model polymers of polynucleotides with linear polyester backbone and nucleic acid base derivative as pending side chains are described. N-(1′,3′-Dihydroxy-2′-methyl-2′-propyl)-2-(thymin-l-yl)propionamide ( Ia , HMPTPA), N-(1′,3′-dihydroxy-2-methyl-2′-propyl)-2-(uracil-l-yl)propionamide ( Ib , HMPUPA), and their isomers, N-(β,β′-dihydroxyethyl)-2-(thynin-1-yl)propionamide ( IIa , HETPA) and N-(β,β′-dihydroxyethyl)-2-(uracil-1-yl)propionamide ( IIb , HEUPA) were synthesized through the selective N-acylation of 2-methyl-2-amino-1,3-propanediol and diethanolamine with 2-(thymin-1-yl)propionic acid (TPA) and 2-(uracil-1-yl)propionic acid (UPA), respectively, by the active amide-benzotriazole method. Diol monomers I and II were polycondenzed with active amide of benzotriazole such as 1,1′-(isophthaloyl)bisbenzotriazole (IPBBT) in the presence of triethylamine and in DMF at 60°C, giving polyesters containing thymine and uracil derivatives as the side group. Prior to polymer synthesis, an O-acylation of Ia using the active monoamide l-benzoylbenzotriazole was carried out as a model compound study.     

Polyvinyl alcohol-modified graphene oxide as a support for bimetallic Pt–Pd electrocatalysts to enhance the efficiency of formic acid oxidation

The aim of this research was to study the efficiency of polyvinyl alcohol (PVA)-modified graphene oxide (GO) as a supporting material for catalysts that oxidize formic acid. The active metal catalysts (e.g., Pt and Pd) were electrodeposited on PVA/GO surfaces. The morphologies of the prepared catalysts were characterized by scanning electron microscopy and transmission electron microscopy, while their chemical compositions were identified by X-ray diffraction and X-ray photoelectron spectroscopy. The results show that compared with the other catalysts on GO, the prepared active PtPd alloy catalyst nanoparticles with 11.49–20.73 nm sizes were well dispersed on the PVA/GO surfaces. Electrochemical results indicate that the activities of the catalysts with PVA provided a higher current density than that of the catalysts without PVA. The bimetallic 3Pt3Pd/PVA/GO catalyst showed the greatest catalytic activity, stability, and CO oxidation when compared to those of other catalysts. The electronic, morphological, and structural properties promote the mass-charge transfer through the interaction. These results indicate that the PVA-modified GO provides a suitable site for active bimetallic catalyst surfaces, resulting in excellent formic acid oxidation and high CO elimination. The 3Pt3Pd/PVA/GO electrocatalyst is promising for enhancing formic acid oxidation.     

Synthetic utility of sydnones to couple pharmacologically important heterocycles for antitubercular activity

In the present investigation we have utilized the 3-arylsydnones 1a–c to couple two biodynamic moieties in amide derivatives 7–10. The 3-arylsydnones were brominated to 4-bromo-3-arylsydnones 2a–c which further were reacted with benzotriazole/benzothiazolin-2-thione/morpholine/diphenylamine to the corresponding final compounds. The structures of the amide derivatives were confirmed by the spectral (IR, ¹H NMR and Mass) and analytical data. Further, these were subjected to the antitubercular activity against Mycobacterium tuberculae (H37Rv). The morpholine 7a–c and benzotriazole 8a–c derivatives have exhibited good inhibition.     

Synthesis of poly(vinyl alcohol) containing asymmetric nucleic acid base derivatives as grafted pendants

The preparations of new model polymers of polynucleotides with linear poly(vinyl alcohol) (PVA) backbones and an optically active nucleic acid base derivative as a pending side chain are described. (±)-, (+)-, and (?)-2-(thymin-1-yl)propionic acid were grafted onto PVA through ester bonds by direct coupling with dicyclohexylcarbodiimide (DCC) in the presence of highly active catalyst 4-pyrrolidinopyridine (PPY) to give optically active graft polymers. The corresponding monomer and dimer models have been prepared.     

Simultaneous spectrophotometric determination of drugs in pharmaceutical preparations using multiple linear regression and partial least-squares regression, calibration and prediction methods

Two new methods for the simultaneous determination of acetylsalicylic acid, acetaminophen and caffeine based on total absorbance measurements and their processing by multiple linear regession and partial least-squares regression are proposed. The concentration ranges used to construct the calibration matrix were 4.0-12.0, 2.0-10.0 and 0.9-6.0 μg ml⁻¹ for acetylsalicylic acid, acetaminophen and caffeine respectively. The proposed methods were validated by using a set of synthetic sample mixtures and subsequently applied to the determination of the three active principles in three different pharmaceutical preparations.