蓝萼甲素固体脂质纳米粒的制备及理化性质研究

目的:制备蓝萼甲素固体脂质纳米粒,并对其理化性质进行研究。方法:用乳化-溶剂挥发法制得蓝萼甲素固体脂质纳米粒,并对其粒径、形态、表面电位、包封率、体外释药性质等进行研究。结果:所得蓝萼甲素固体脂质纳米粒的粒径分布均匀,平均粒径为(190±10·3)nm,Zeta电位为—31·2mV,平均包封率为(50·45±0·804)%;药物体外释放符合Higuchi线性方程,具有显著缓释作用。结论:固体脂质纳米粒可作为蓝萼甲素新型缓释给药系统。     

美洛昔康固体脂质纳米粒的制备及体外透皮研究

摘 要 目的： 制备美洛昔康固体脂质纳米粒,并考察其透皮吸收行为。方法: 采用热熔乳化超声 低温固化法制备美洛昔康固体脂质纳米粒,并考察其包封率、粒径分布、Zeta电位、微观形态及体外药物释放特性,采用Franz扩散池考察其透皮吸收行为。结果: 美洛昔康固体脂质纳米粒的包封率为（85.6±2.7）%,平均粒径为（213.5±52.6）nm,Zeta电位为（-32.2±3.9）mV,透射电镜显示美洛昔康固体脂质纳米粒粒径均一,成球状分布。其12 h药物累积透皮量显著高于美洛昔康溶液。结论: 美洛昔康固体脂质纳米粒可以显著提高药物累积透皮量,有望成为美洛昔康的新型局部给药制剂。     

乳化蒸发法制备固体脂质纳米粒

目的：采用乳化蒸发法制备固体脂质纳米粒,并考察其载药性能。方法：对影响固体脂质纳米粒质量的工艺因素和处方因素进行考察和优化设计,得到最优处方。选用模型药物酮洛芬制备载药固体脂质纳米粒,考察其包封率和体外释放行为。结果：所得固体脂质纳米粒平均粒径为（228.2±18.1）nm,多分散系数为（0.217±0.022）,ξ电位为-（21.4±0.6）mV。载药固体脂质纳米粒最佳包封率为（64.1±3.3）%,体外释放行为符合Weibull模型。结论：采用乳化蒸发法制备固体脂质纳米粒是可行的。     

吡喹酮固体脂质纳米粒的制备及其理化性质研究

目的:制备吡喹酮固体脂质纳米粒(PZQ-SLN),并考察其理化性质。方法:以山嵛酸甘油酯和乙酸丁酯为脂质材料,超声分散法制备PZQ-SLN,透射电镜观察纳米粒形态,测定其粒径、Zeta电位和药物包封率,并进行体外释放试验及考察样品的稳定性。结果:所得脂质纳米粒为类圆球状,粒径分布较均匀。样品粒径为(100±21)nm,包封率为(79.3±0.69)%,平均Zeta电位值为—66.3mV。药物体外释放符合Weibull方程。4℃放置3mo后粒径、包封率和Zeta电位均无明显变化。结论:制备的PZQ-SLN理化性质较为理想,能使药物缓慢释放。4℃条件下贮存比较稳定。     

大黄素固体脂质纳米粒的制备及理化性质研究

目的：制备大黄素固体脂质纳米粒,并对其理化性质进行研究。方法：用乳化一溶剂挥发法制得大黄素素固体脂质纳米粒,并对其粒径、形态、表面电位、包封率、体外释药性质等进行研究。采用全体液平衡反向透析法研究体外释药性质。结果：所制固体脂质纳米粒外观形态圆整,粒度分布均匀,平均粒径为253nm,电位为一25．4mV,包封率为（56．31±2．06）％。药物体外释放符合Weibull线性方程。结论：固体脂质纳米粒可作为大黄素新型缓释给药系统。     

不同粒径多西他赛固体脂质纳米粒制剂及其细胞毒活性

目的制备不同粒径的多西他赛(docetaxel,DTX)固体脂质纳米粒,考察多西他赛固体脂质纳米粒理化性质,研究粒径对体外释放行为以及细胞毒作用的影响。方法通过热熔超声法制备不同粒径多西他赛固体脂质纳米粒,观察纳米粒形态,测定其包封率、粒径、Zeta电位。考察粒径因素对固体脂质纳米粒体外释放行为、体外细胞毒性的影响。结果制备的纳米粒均为球形及类球形,3种粒径的多西他赛固体脂质纳米粒平均粒径分别为(83.7±8.4)、(162.7±11.9)、(232.1±26.4)nm;Zeta电位分别为-24.19、-23.67、-23.19 mV;包封率分别为98.03%、97.84%、97.92%。60 h粒径分别为83、16、232 nm的多西他赛固体脂质纳米粒在释放介质中分别累计释放86.34%、76.98%、67.14%。3种不同粒径多西他赛固体脂质纳米粒(DTX-SLN-83,DTX-SLN-162,DTX-SLN-232),多西他赛原料药(DTX solutions)以及空白SLN溶液与多西他赛的混合溶液(physi-calm ixture)对MCF-7细胞作用24 h的IC50值分别为3.36、6.20、9.74、13.15、12.92 mg.L-1;48 h的IC50值分别为0.93、2.01、4.35、9.48、9.21 mg.L-1;72 h的IC50值分别为0.30、0.91、1.67、7.36、7.82 mg.L-1。随着多西他赛固体脂质纳米粒粒径的减小,其肿瘤细胞杀伤力逐渐增强。结论热熔超声法可用于制备不同粒径多西他赛固体脂质纳米粒。降低固体脂质纳米粒粒径有利于药物更完全地释放,同时增强其对肿瘤细胞的杀伤能力。     

糠酸莫米松固体脂质纳米粒的制备

目的：研究糠酸莫米松固体脂质纳米粒的处方和制备工艺，并对其质量进行评价。方法：用乳化-溶剂挥发法制备糠酸莫米松固体脂质纳米粒，以包封率为指标采用正交设计法优选处方，用透射电镜和激光粒径测定仪测定纳米粒的形态和粒径，用低速离心法测定药物的包封率。结果：制得的糠酸莫米松固体脂质纳米粒形态规整，几呈球形，体积均粒径为73．8nm，包封率为（92．8±0．89）。结论：本研究所得的处方和工艺可制备性能优良的糠酸莫米松固体脂质纳米粒。     

全反式维甲酸固体脂质纳米粒的制备及体内外评价

目的以山嵛酸甘油酯(Compritol 888 ATO)为脂质材料，采用超声分散法制备维甲酸固体脂质纳米粒，并考察其体内外性质。方法选用脂溶性较高的维甲酸作为模型药物，采用超声分散法制备固体脂质纳米粒，并对其各种理化性质进行研究。考察了纳米粒的体外释放，以维甲酸溶液剂为对照，测定了两种纳米粒在大鼠体内的药代动力学参数。结果采用超声分散法可以简便、快速制备得到两种维甲酸固体脂质纳米粒，透射电镜测得纳米粒为圆球状，大小均匀。动态光散射法测得平均粒径分别为(158±9) nm和(89±11) nm。于4 ℃放置1年粒径无明显变化，载药量为3.3%，包封率大于95%。药物体外释放符合Weibull方程。与对照组相比，两种维甲酸固体脂质纳米粒静脉注射后药物在血液中的滞留时间显著延长。结论超声分散法适用于固体脂质纳米粒的制备。     

辛伐他汀固体脂质纳米粒的制备及在大鼠体内的药动学研究

摘 要 目的： 制备辛伐他汀固体脂质纳米粒,并研究其经灌胃给药后在大鼠体内的药动学特征。方法: 采用热熔乳化超声 低温固化法制备辛伐他汀固体脂质纳米粒,考察辛伐他汀固体脂质纳米粒的粒径分布、Zeta电位、包封率、微观形态及体外药物释放特性。研究辛伐他汀固体脂质纳米粒经灌胃给药后在大鼠体内的药动学特征。结果: 辛伐他汀固体脂质纳米粒平均粒径为(242.5±62.1) nm,多聚分散系数为0.225±0.031,Zeta电位为(-32.1±4.2) mV,包封率为(95.7±2.6) %,在24 h内平稳缓慢释药。辛伐他汀固体脂质纳米粒在大鼠体内的Cmax和AUC0 t分别为辛伐他汀混悬液的2.89倍和1.83倍。结论:辛伐他汀固体脂质纳米粒在大鼠体内能快速吸收,显著提高了药物在大鼠体内的生物利用度。     

吡喹酮-硬脂酸固体脂质纳米粒的制备及性能评价

目的：制备吡喹酮-固体脂质纳米粒,考察其理化性质和体外释放度。方法：以硬脂酸为脂质材料,聚乙烯吡咯烷酮为乳化剂,利用热熔乳化超声法制备吡喹酮-固体脂质纳米粒,扫描电镜观察纳米粒形态和均匀度,纳米粒度仪测定其粒径、分散指数、Zeta电位、包封率和载药量,并进行体外释放试验。结果：制备的固体脂质纳米粒为类圆球状,粒径分布较均匀、表面光滑。纳米的平均粒径、分散指数、电位、包封率和载药量分别为（316.5±22.8）nm、0.23±0.05、（-25.3±0.7）mV,（92.64±5.12）%和（18.45±1.34）%。药物在制剂的过程中稳定性良好。体外释放表明吡喹酮-硬脂酸固体脂质纳米粒在生理盐水中具有一定程度的突释和显著的缓释效果。结论：本试验制备的吡喹酮-硬脂酸固体脂质纳米粒具有较好的均匀度和高载药量,并具有良好的缓释性能。     

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.     

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.     

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.