醋酸地塞米松PEG-PLGA纳米粒的制备及表征

目的 研究醋酸地塞米松PEG-PLGA纳米粒的制备工艺及影响因素,并优化冻干粉针工艺.方法 采用乳化/溶剂蒸发法制备醋酸地塞米松PEG-PLGA纳米粒,并考察其粒径分布、包封率、载药量等;采用单因素试验筛选出合适的冻干保护剂.结果 醋酸地塞米松PEG-PLGA纳米粒的粒径为91.43±1.00 nm,Zeta电位为-22.73 ±0.57 mv,包封率为88.78％ ±2.10％,载药量为4.95％-±0.23％;10％蔗糖作为冻干保护剂的效果最好,冻于复溶后粒径约117.27 nm.结论 所用制备工艺简单易行,可用于制备醋酸地塞米松PEG-PLGA纳米粒.     

替尼泊苷多层包衣白蛋白纳米粒的制备工艺及体外抗肿瘤活性

目的以人血清白蛋白为载体包载替尼泊苷,经过包衣修饰后制备包载替尼泊苷的多层包衣纳米粒(teniposide-encapsulated multilayer nanoparticles,P-CS-NP),以期降低药物的不良反应并改善其体外抗肿瘤活性。方法以粒径、多分散指数和载药率为评价指标,采用单一因素法筛选出替尼泊苷白蛋白纳米粒的最优处方工艺,通过加入壳聚糖和聚谷氨酸聚乙二醇共聚物进一步制备多层包衣白蛋白纳米粒,筛选得到最优包衣量。以游离的替尼泊苷作为参比,用MTT法测定纳米粒对人肺癌A549细胞的体外细胞毒性,并用流式细胞仪和共聚焦显微镜测定和观察多层包衣纳米粒的细胞摄取率和细胞摄取行为。结果确定了多层包衣纳米粒的处方及制备工艺。多层包衣纳米粒的体外细胞毒性比游离的替尼泊苷小,摄取具有时间依赖性,与壳聚糖共孵育的纳米粒的细胞摄取量增加,入胞后纳米粒主要分布在细胞质。结论白蛋白纳米粒能被壳聚糖和聚谷氨酸聚乙二醇共聚物包衣修饰,多层包衣纳米粒可以作为替尼泊苷的药物递送载体,其体外细胞毒性降低。     

紫杉醇MPEG-PCL纳米粒的制备、表征及其体外释药行为研究

目的 以聚乙二醇单甲醚-聚己内酯(MPEG-PCL)为载体制备紫杉醇MPEG-PCL纳米粒并对其体外释放行为进行考察。方法 采用开环聚合法合成MPEG-PCL共聚物,采用核磁共振波谱仪(¹H-NMR)、傅里叶红外光谱仪(FTIR)对其进行表征;通过共沉淀法制备了紫杉醇MPEG-PCL纳米粒,并测定了粒径分布、Zeta电位、结构特征、包封率以及载药量;同时以磷酸盐缓冲溶液(pH=7.4)为释放介质考察其体外释放行为。结果 成功合成了相对分子质量为4 875的MPEG-PCL共聚物。透射电镜结果显示紫杉醇MPEG-PCL纳米粒具有规则的球形结构,纳米粒的平均粒径为(102.3±3.5)nm,PDI=0.102,药物包封率和载药量分别为(95.6±3.2)%和(8.5±0.4)%。体外释放结果显示紫杉醇可以缓慢的从MPEG-PCL纳米粒中释放出来。结论 MPEG-PCL共聚物是紫杉醇的良好载体,所制备的纳米粒具有包封率和载药量高、药物释放缓慢的特点。     

红霉素白蛋白纳米粒的制备及体内药动学研究

摘要：目的:制备红霉素白蛋白纳米粒,以提高红霉素的生物利用度。方法:采用去溶剂化高压均质法制备红霉素白蛋白纳米粒,以载药量、包封率、粒径及多分散系数为评价指标。通过单因素考察及正交试验进行最佳处方工艺的筛选,并对最佳处方工艺进行表征。SD大鼠随机分成2组,分别尾静脉注射红霉素混悬液与红霉素白蛋白纳米粒,比较药动学参数。结果:当药物与白蛋白比例为1∶3、有机相体积为4 ml、高压均质10次、有机相加入方式为注射器注入、搅拌时间为5 h、搅拌速度为700 r·min-1时,所制备的白蛋白纳米粒性质最优,最佳工艺下包封率为（65.61±1.02）%,载药量为（36.49±1.33）%,平均粒径为（280.71±5.82） nm,多分散系数（PDI）为0.20±0.04,电位为-（11.91±2.29） mV。与原料药相比,白蛋白纳米粒的最大血药浓度(Cmax)提高了5.8倍,血药浓度-时间曲线下面积(AUC0→12)提高了5.15倍（P<0.01）。结论:以去溶剂化高压均质法制备的红霉素白蛋白纳米粒制备方法简单,制剂稳定性良好,能显著提高红霉素的体内生物利用度。     

Box-Behnken效应面法优化姜黄素正负离子固体脂质纳米粒的处方

目的 采用Box-Behnken效应面法筛选姜黄素正负离子固体脂质纳米粒的最优处方.方法 采用乳化蒸发-低温固化法制备姜黄素的固体脂质纳米粒,以固体脂质的质量、卵磷脂的质量和混合表面活性剂为考察对象,以包封率和脂质载药量为考察指标,利用3因素3水平Box-Behnken效应面设计法筛选姜黄素固体脂质纳米粒的最优处方.结果 按最优处方制备固体脂质纳米粒的包封率为94.20％ ±2.55％、脂质载药量为3.49％±0.11％,平均粒径为194.9 ±12.0 nm,Zeta电位为-28.15 ±2.72 mV.结论 采用Box-Behnken效应面法优化姜黄素正负固体脂质纳米粒的处方是有效、可行的.     

半乳糖化阿霉素白蛋白纳米粒的制备及其质量评价

目的:制备半乳糖化阿霉素白蛋白纳米粒,并考察了其形态、粒径、载药量、包封率和体外释药特性.方法:采用相分离法制备阿霉素白蛋白纳米粒,并在其表面偶联半乳糖苷,使之成为半乳糖化白蛋白纳米粒.激光扫描电子显微镜观察纳米粒的形态,马尔文激光粒度仪测定其粒径分布.采用紫外分光光度法测定纳米粒的载药量和包封率,并初步研究其体外释药特性.结果:电镜结果显示阿霉素纳米粒呈类球型,平均粒径为316.3 nm,纳米粒载药量为3.12%,包封率达91.82%,48 h体外累积释药率为55.71%.结论:本方法制备阿霉素纳米粒工艺简单且包封率较高.体外释药结果显示半乳糖化阿霉素白蛋白纳米粒具有明显的缓释作用.     

以叶酸修饰的乳酸-羟基乙酸共聚物为载体的紫杉醇靶向纳米粒的构建与评价

目的 以叶酸修饰的生物可降解材料乳酸-羟基乙酸共聚物(PLGA-PEG-FOL)为载体,构建紫杉醇靶向纳米粒并进行评价。方法 采用乳化-分散法,以溶液稳定性、粒径和包封率为评价指标,通过考察乳化剂的用量、有机相种类、水相与有机相比例、聚合物分子量、药载比、剪切速度等因素对纳米粒制备的影响,确定最优处方和制备工艺,并对纳米粒的形态、粒径、Zeta电位、包封率及载药量进行评价。结果 合成了载体PLGA-PEG-FOL;制备的紫杉醇靶向纳米粒为均匀球形粒子,粒径为(88.2±6.7)nm,Zeta电位为(56.5±4.2)mV,包封率为(92.9±3.2)%,载药量为(4.8±1.3)%。结论 纳米粒制备方法简便易行,重现性好。制备的纳米粒大小均匀,粒度分布较窄,包封率和载药量较高。     

以PLGA-PEG-FOL为载体的紫杉醇靶向纳米粒的构建与评价

目的 以叶酸修饰的生物可降解材料乳酸-羟基乙酸共聚物(PLGA-PEG-FOL)为载体,构建紫杉醇靶向纳米粒并进行评价。方法 采用乳化-分散法,以溶液稳定性、粒径和包封率为评价指标,通过考察乳化剂的用量、有机相种类、水相与有机相比例、聚合物分子量、药载比、剪切速度等因素对纳米粒制备的影响,确定最优处方和制备工艺,并对纳米粒的形态、粒径、Zeta电位、包封率及载药量进行评价。结果 合成了载体PLGA-PEG-FOL;制备的紫杉醇靶向纳米粒为均匀球形粒子,粒径为(88.2±6.7)nm,Zeta电位为(56.5±4.2)mV,包封率为(92.9±3.2)%,载药量为(4.8±1.3)%。结论 纳米粒制备方法简便易行,重现性好。制备的纳米粒大小均匀,粒度分布较窄,包封率和载药量较高。     

葛根素磷脂复合物纳米粒的制备及体外评价

目的制备葛根素磷脂复合物,以聚氰基丙烯酸正丁酯(PBCA)为载体材料,制备葛根素磷脂复合物纳米粒,并对其进行体外评价。方法采用界面缩合聚法制备纳米粒。以复合率、包封率和载药量为评价指标,通过单因素和正交试验法优选处方和工艺。结果葛根素磷脂复合物的最佳处方及工艺:反应溶剂为无水乙醇,葛根素与磷脂的投料比为1∶2;葛根素磷脂复合物纳米粒的最佳处方及工艺:pH=3.0、α-氰基丙烯酸正丁酯(α-BCA)的浓度为0.8%、V油相∶V水相=1∶60、葛根素磷脂复合物的投药量为1.0 mg。制备的纳米粒平均粒径为(115.1±3.45)nm、包封率为(90.03±1.80)%、载药量为(11.80±0.12)%。体外释药在24 h累积释放量约为80%。结论本研究所制备的葛根素磷脂复合物纳米粒包封率和载药量高、性质稳定、体外释药具有缓释行为。     

载基因壳聚糖纳米粒的制备及其相关性质的初步研究

目的制备壳聚糖载基因纳米粒,并对其体外相关性质进行初步研究。方法采用复凝聚法制备载基因纳米粒;用纳米粒度仪测量粒度分布、多分散性和Zeta电位;用透射电镜观察粒子的形态;用荧光分光光度法和比色法测定包封率和载药量,并对主要影响因素进行考察;用凝胶阻滞分析和电性结合分析对载药方式进行初步推测。结果所制备的载基因纳米粒形态规则,大多呈球形,平均粒径约150nm,PDI＜0．2,Zeta电位约20mV;包封率大于90％,载药量约30％;凝胶阻滞和电性结合分析结果表明,pDNA与壳聚糖分子间可通过电性结合作用而完全结合。结论采用复凝聚法可制备粒度分布均匀,形态规则,具有较高包封率和载药量的载基因壳聚糖纳米粒;电性结合作用是载基因壳聚糖纳米粒载药的主要方式。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.