改良自乳化-溶剂扩散法制备甲基莲心碱纳米粒的研究

目的制备甲基莲心碱纳米粒(NEF-NP),并采用正交试验设计对甲基莲心碱纳米粒制备工艺进行优化。方法以包封率和载药量为评价指标,采用聚乳酸-羟基乙酸共聚物(PLGA)为载体,丙酮-无水乙醇为有机溶剂,通过正交设计优化改良自乳化-溶剂扩散法制备载NEF的PLGA载药纳米粒的处方工艺。结果优化的最佳处方工艺为:PLGA的浓度为20 mg.mL-1,NEF的投药量为3.3 mg,PVA浓度为1.0%,水相与有机相的体积比为8∶1。最佳条件下制得的纳米粒平均包封率达(70.35±1.16)%,载药量(2.33±1.08)%,平均粒径为(213.5±2.7)nm。结论最佳处方工艺制备的NEF-PLGA纳米粒具有较高的包封率、载药量和较小的粒径。     

利福布汀-PLGA纳米粒的制备

目的:制备利福布汀(RB)-聚乳酸-羟基乙酸共聚物(PLGA)纳米粒,并对制备工艺进行优化。方法:采用改良的自乳化溶剂挥发法制备;通过单因素法考察对包封率影响较大的因素,在此基础上以包封率为指标采用正交设计优化纳米粒的制备工艺并进行验证。结果:对纳米粒包封率影响较大的因素是RB与PLGA投药比、PLGA浓度、混合有机相中丙酮比例及油水相比;上述各因素的最佳水平分别是1:2、40mg·mL-1、70%、1:5。验证试验中所制纳米粒平均粒径为(201±19)nm、包封率为(59.1±5)%、载药量为(15.1±2.4)%。结论:本文的制备方法简单,所得纳米粒粒径小、质量稳定。     

细胞膜红色荧光探针PLGA纳米粒的制备及表征

目的以聚乳酸-羟基乙酸共聚物(PLGA)和单甲氧基聚乙二醇聚乳酸-羟基乙酸共聚物(MePEG-PLGA)为材料,制备包载细胞膜红色荧光探针(DiI)的纳米粒,为后续的细胞实验奠定基础。方法采用自乳化溶剂扩散法制备纳米粒;超滤法分离纯化纳米粒,紫外可见分光光度法测定DiI的含量,并计算包封率。结果 DiI用量为0.5 mg,PLGA或MePEG-PLGA投入量为50 mg,PVA浓度为0.5%,可制得粒径较合适的纳米粒。DiI-PLGA-NP平均粒径为(280.7±3.6)nm,Zeta电位为(2.98±0.47)mV,包封率可达88.0%;DiI-MePEG-PLGA-NP平均粒径为(157.2±3.2)nm,Zeta电位为(-4.90±0.54)mV,包封率可达87.1%。结论 DiI作为脂溶性良好的示踪剂,用其制得的荧光素纳米粒可为后续的体外实验奠定良好的基础。     

盐酸维拉帕米PLGA纳米粒的成型工艺及制剂学性质研究

目的 优化影响盐酸维拉帕米乳酸/羟基乙酸共聚物(PLGA)纳米粒成型工艺的参数,并评价优化工艺后所制纳米粒的制剂学性质.方法 采用O/W超声乳化-溶剂挥发法制备盐酸维拉帕米PLGA纳米粒(VRP-PLGANP),以粒径、包封率和载药量为评价指标,采用单因素试验系统考察PLGA浓度、PLGA/VRP质量比、PVA浓度、有机相中丙酮浓度、外水相pH、内外相(O/W)体积比、探头超声时间、旋蒸时间共8个参数对纳米粒成型工艺的作用规律.结果 用优化处方工艺制备的纳米粒的包封率和载药量分别为65.78%±6.32%和22.75%±1.48%、平均粒径为150.4±6.9 nm、PDI=0.070±0.018(n=3),体外释放规律符合Weibull方程,具有一定的缓释特性.结论 所用方法可用于制备载两亲性药物的PLGA纳米粒.     

人参皂苷Rg3 PLGA纳米粒的处方优化及制备工艺研究

目的为了提高人参皂苷Rg3的生物利用度和靶向性,以聚乳酸-羟基乙酸共聚物(PLGA)为载体材料,研究人参皂苷Rg3 PLGA纳米粒的处方和制备工艺。方法采用纳米沉淀法制备纳米粒,HPLC测定人参皂苷Rg3的含量。以包封率为指标,采用单因素和正交试验法优选处方和工艺。结果人参皂苷Rg3 PLGA纳米粒的最佳处方和工艺条件为:PLGA浓度为10 mg·m L-1,人参皂苷Rg3浓度为3 mg·m L-1,有机相与水相体积比为1:3。制备的纳米粒平均粒径为186.1 nm,包封率为87.29%。结论该工艺方法简便、稳定可行,适用于人参皂苷Rg3 PLGA纳米粒的制备。     

姜黄素PLGA纳米粒的制备及制剂学性质分析

目的制备姜黄素(Curcumin,Cur)聚乳酸羟基乙酸共聚物(PLGA)纳米粒(Cur-PLGA-NPs)并对其理化性质进行考察。方法采用改良的自乳化溶剂挥发法制备纳米粒,通过正交设计,以粒径、包封率和载药量为评价指标优化处方工艺。结果制备Cur-PLGA-NPs的优化条件为PLGA 100 mg,泊洛沙姆188浓度1.0%,丙酮与乙醇体积比3∶1,有机相体积15 m L。按优化条件所制备的Cur-PLGA-NPs粒径为(120.33±2.44)nm,多分散系数为0.10±0.02,包封率为84.50%±1.13%,载药量为4.75%±0.22%。结论采用改良的自乳化溶剂挥发法成功制备了Cur-PLGA-NPs,为后续"纳米粒-脂质体系统"的研究奠定了基础,有望实现药物在肝脏的浓集。     

因子设计-效应面法优化紫杉醇聚乳酸-羟基乙酸纳米粒处方和制备工艺

目的:优化紫杉醇聚乳酸-羟基乙酸(PLGA)纳米粒处方和制备工艺.方法:以PLGA为载体,采用溶剂扩散法制备紫杉醇PLGA纳米粒,用32满因子设计实验,考察因素PLGA在有机相中的浓度和理论载药量对纳米粒的粒径、载药量和包封率的影响,实验数据分别采用线性方程和二次多项式拟合,根据最佳数学模型绘制效应面并选出最优处方.结果:2个影响因素和3个评价指标之间存在定量关系,最优处方为:紫杉醇的理论载药量为9.09%、有机相中PLGA浓度为2%,制备得到的纳米粒粒径为281 nm,实际载药量为7.73%,包封率为57.43%.结论:采用因子设计-效应面法完成了紫杉醇纳米给药系统的多目标同步优化.     

利福平聚乳酸-羟基乙酸共聚物纳米粒的成型工艺及制剂学性质分析

目的优化利福平聚乳酸-羟基乙酸共聚物纳米粒(RFP-PLGA-NPs)的制备工艺,并分析其制剂学性质。方法以PLGA为载体,采用改良的自乳化溶剂蒸发法(M-SESD)制备RFP-PLGA-NPs。以粒径、包封率、载药量为指标,采用正交设计法优化处方和制备工艺。结果制备RFP-PLGA-NPs的优化条件为PLGA 100 mg,poloxsmer 188质量分数1.0%,丙酮与乙醇体积比3:1,有机相体积15 mL。按优化条件所制备的RFP-PLGA-NPs的粒径为(128.73±4.07)nm,多分散系数(PDI)为0.046～0.105,包封率(65.84±0.69)%,载药量(3.78±0.14)%。结论该工艺简单、稳定性好,为后续RFP-PLGA-NPs的体内研究奠定了基础。     

5-氟尿嘧啶纳米粒的制备及其体外释药的研究

目的以生物可降解材料乳酸/羟基乙酸共聚物(PLGA)制备5-氟尿嘧啶(5-FU)纳米粒,并考察纳米粒的体外释放特性。方法采用复乳-溶剂挥发法结合高压均质法制备5-Fu-PLGA纳米粒,用透射电镜观察纳米粒的形态,并研究了5-Fu纳米粒的粒径、载药量、包封率和体外释药。结果5-FU-PLGA纳米粒为圆整的类球形实体粒子,平均粒径为85.4nm,载药量为12.4%±0.7%,包封率为64.1%±5.3%,体外释药符合H iguch i方程:Q=0.0585t1/2 0.087(r=0.9923)。结论所制5-FU纳米粒具有明显的缓释作用。     

芍药苷聚乳酸-羟基乙酸共聚物纳米粒制备工艺的优化及对心肌细胞的保护作用

目的:优化芍药苷聚乳酸-羟基乙酸共聚物(PLGA)纳米粒制备工艺,并探讨芍药苷PLGA纳米粒对H₂O₂诱导损伤的H9c2心肌细胞的保护作用。方法:首先使用复乳-溶剂挥发法制备芍药苷PLGA纳米粒,采用Plackett-Burman设计实验以及Box-Behnken响应面设计实验对其制备工艺进行优选,得出最佳处方,并对按最佳处方制备的芍药苷PLGA纳米粒进行表征分析、4℃储藏稳定性考察以及体外释放考察;最后通过H₂O₂诱导建立大鼠H9c2心肌细胞氧化损伤模型,考察芍药苷PLGA纳米粒对心肌细胞的保护作用,CCK-8法检测细胞存活率,试剂盒检测心肌细胞乳酸脱氢酶(LDH)漏出量、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量。结果:最佳处方：泊洛沙姆浓度为0.4%,给药量为3.1 mg, PLGA为21.4 mg;所得芍药苷PLGA纳米粒包封率为(45.49±0.29)%,载药量为(4.52±0.05)%,粒径为(115.1±3.61) nm,多分散系数(polydiseperse index, PD...     

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.     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

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.