Synthesis of zirconia/polyethylene glycol hybrid materials by sol–gel processing and connections between structure and release kinetic of indomethacin

Abstract

Controlled and local drug delivery systems of anti-inflammatory agents are attracting an increasing attention because of their extended therapeutic effect and reduced side effects. In this work, the sol–gel process was used to synthesize zirconia/polyethylene glycol (ZrO₂/PEG) hybrid materials containing indomethacin for controlled drug delivery. Different percentages of PEG were introduced in the synthesis to modulate the release kinetic and an exhaustive chemical characterization of all samples was performed to detect the relationship between their structure and release ability. Fourier transform spectroscopy and solid-state NMR show that the Zr–OH groups of the inorganic matrix bond both the ethereal oxygen atoms of the polymer and the carboxylic groups of the drug. X-ray diffraction analysis ascertains the amorphous nature of those materials. Scanning electron microscopy detects the nanostructure and the homogeneous morphology of the synthesized materials.

The bioactivity was demonstrated by the formation of a hydroxyapatite layer on the surface of the samples, after soaking in a simulated body fluid. The release kinetics study, performed by HPLC UV–Vis spectroscopy, proves that the release ability depends on PEG and the drug amount and also demonstrates the indomethacin integrity after the synthetic treatment.     

UV-irradiation-induced bioactivity on TiO2 coatings with nanostructural surface

Titania (TiO₂) coatings with nanostructural surface prepared using plasma spraying technology were irradiated by ultraviolet light in simulated body fluids to improve their bioactivity. The in vitro bioactivity of the coatings was evaluated by investigating the formation of apatite on their surfaces in simulated body fluids. Bone-like apatite was observed to precipitate on the UV-irradiated TiO₂ coating with nanostructural surface after it was immersed in simulated body fluid for a certain period, but not on the as-sprayed and UV-irradiated TiO₂ coatings without nanostructural surface. The results indicate that the nano-TiO₂ surface can be activated by UV-irradiation to induce its bioactivity. The ability of apatite formation on the nano-TiO₂ surface was improved with the increase of UV-irradiation time. The in vivo results reveal that the as-prepared TiO₂ coating with nanostructural surface cannot induce the formation of new bones during the implantation period, but the UV-irradiated TiO₂ coating with nanostructural surface could do so during an implantation time longer than 2 months. Our results indicate that the osseointegration ability of the plasma-sprayed TiO₂ coating with nanostructural surface can be improved by UV irradiation.     

人白细胞介素6表达的核因子蛋白在大肠杆菌中的表达与鉴定

将ＮＦ－ＩＬ６基因与谷胱甘肽转移酶（ＧＳＴ）基因融合并成功地表达出具有生物活性的ＮＦ－ＩＬ６，经ＧｅｌＲｅｔａｒｄａｔｉｏｎ分析证实该重组蛋白能与其ＤＮＡ识别元件结合。实验还发现，虽然重组蛋白的表达率较低，但能形成不溶性包含体     

Isolation and biochemical properties of four forms of glycosylated porcine prolactin

Four isoforms of glycosylated prolactin (G-pPRL) were isolated from porcine pituitary glands by affinity chromatography and concanavalin A-Sepharose, based upon differences in their affinity for the lectin. Structural analysis indicated differences in the carbohydrate units of the four G-pPRLs. N-glycanase treatment cleaved the oligosaccharide from the G-pPRLs, establishing N-linked glycosylation. The binding of G-pPRLs to receptors from lactating rabbit mammary glands was only 3–8% that of nonglycosylated pPRL (NG-pPRL). The immunological crossreactivity of the G-pPRLs varied from 36 to 65% that of NG-pPRL. When tested in the pigeon crop sac bioassay, G-pPRLs were only 11–40% as active as NG-pPRL. The metabolic clearance rate of one of the G-pPRLs was slower and another faster than that of NG-pPRL. We conclude that there are several forms of G-PRL of variable immuno- and bio-potencies in the porcine pituitary, and that the current radioimmunoassay for the hormone does not measure the actual bioactivity.     

生物活性陶瓷人骨复合材料的理化性能测试

目的 通过生物活性陶瓷人骨复合材料的理化性能的测试，以了解其生物相容性。方法 以Ca(OH)2、H3PO4、无机氟、Ca、Si、Na、P等金属和非金属氧化物为原料，采用高温、熔融、烧结、结晶、析出等方法，合成5种生物活性陶瓷。以原子吸收法，发射光谱法和钼蓝比色法测定了5种材料在水中Ca、P、F的溶出；以万能实验机测定材料的抗压强度；以电镜扫描观察材料的结构。结果Ca、P、F在5种材料中的平均溶出均比空白高。羟基磷灰石的平均抗压强度明显高于其他4种材料。结论 不同材料Ca、P、F溶出物，抗压强度及结构均有所不同。     

泽泻的研究现状与展望

综述了泽泻的化学成分、药理作用、提取方法、药材与质量评价及应用现状,对泽泻的进一步研究及开发利用进行了展望。     

海洋放线菌活性代谢产物研究最新进展

近年来海洋放线菌代谢产物的研究取得了很大进展，从海洋放线菌中分离到许多结构新奇、有特殊生理活性和有潜在实用价值的新化合物。研究表明海洋放线菌有可能成为抗生素等药物工业的又一重要微生物资源。本文分类介绍了2001年到2005年间海洋放线菌代谢产物的研究进展，重点在于从海洋放线菌发现的新化合物及其生物活性。     

稀土与亮氨酸、咪唑三元配合物的合成及其性能研究

目的:稀土、亮氨酸、咪唑三元配合物的合成及其性能考察。方法:在乙醇介质中,以氯化稀土盐与L-亮氨酸、咪唑反应合成三元固态配和物,利用化学分析、元素分析、红外光谱分析、摩尔电导率测定及热重分析、生物活性试验等方法对配合物的组成结构、性质性能、热分解机制与热稳定性及抑菌作用等进行研究。结果:确定配合物的组成结构为1∶3型电解质[RE(Leu)3I m(H2O)]Cl3·2H2O,并初步确定了该配合物的热分解动力学过程、稳定性及对大肠杆菌的抑菌作用。结论:合成的三元配合物组成及性能稳定,初试具有良好的抑菌作用。     

ELISA法分析HIV-1整合酶的生物学活性

目的:建立一种能够较好地分析HIV-1整合酶的生物学活性以及大规模地筛选整合酶抑制剂的方法。方法:HIV-1整合酶经表达复性及纯化后,采用一种基于Biotin-Avidin EILSA(BA-ELISA)的方法,使用化学发光底物测定分析整合酶的生物学活性,以及型核糖体失活蛋白luffin-a对整合酶的抑制作用。结果:1采用BA-ELISA法得到整合酶的比活性为54.92U/mg蛋白;2luffin-a对整合酶的半数抑制浓度为(0.63±0.026)μmol/L。结论:本实验所采用的基于BA-ELISA的方法能够较好地分析HIV-1整合酶的生物活性,适合于大规模体外HIV-1整合酶抑制剂的筛选。     

泽泻现代研究概况

论述了传统中药材泽泻的化学成分,整理了泽泻药理作用的报道,找出了泽泻的主要有效成分,对其炮制沿革进行考究,并对质量标准的研究作了比较和评价。