盐酸吉西他滨壳聚糖纳米粒的制备及其体外释药特性研究

目的:优化盐酸吉西他滨壳聚糖纳米粒的制备参数,考察纳米粒体外释药特性。方法:以壳聚糖为辅料,采用离子交联法制备盐酸吉西他滨壳聚糖纳米粒,以包封率、载药量、粒径为参考指标设计试验,确定优化制备参数,以透射电镜观察其表观特征,考察纳米粒体外释药程度。结果:以优化参数制备的盐酸吉西他滨壳聚糖纳米粒包封率为(78.93±1.52)%,载药量为(11.71±0.88)%,纳米粒的平均粒径为(169±24)nm,体外释放试验表明纳米粒中盐酸吉西他滨的释放过程符合Higuchi方程。结论:盐酸吉西他滨可以通过离子交联法制备壳聚糖纳米粒,其粒径、包封率、载药量可控,具有缓释效果。     

盐酸伊立替康纳米粒的制备及体外评价

目的:制备盐酸伊立替康纳米粒,并对其纳米粒形态、粒径、包封率和释放进行评价。方法:采用沉淀法制备盐酸伊立替康纳米粒,以包封率作为考察指标,筛选最优处方。用透射电镜观察纳米粒形态,激光粒径测定仪测定粒径,凝胶过滤法测定药物的包封率,透析法考察体外释药特质。结果:盐酸伊立替康纳米粒形态规整,几呈球形,强度径为(193.5±2.5)nm,载药量为26.35%,包封率为(98.00±0.01)%,体外24h的累积释放率为62.09%,比水溶液释放慢。结论:通过优化处方和工艺,制备出的盐酸伊立替康纳米粒粒径均匀,包封率较高,体外释药具有缓释特点。     

阿霉素壳寡糖纳米粒的制备及体外抗肿瘤研究

目的制备负载阿霉素的壳寡糖纳米粒,并研究其理化性质和体外抗肿瘤细胞毒性。方法采用离子凝胶法制备负载阿霉素的壳寡糖纳米粒;透射电镜观察纳米粒形态,激光粒度仪测定粒径和表面电位,紫外分光光度法测量包封率、载药量,考察载药纳米粒的体外释药特性;采用MTT法对载药壳寡糖纳米粒在体外乳腺癌细胞株MCF-7的细胞毒作用进行评价。结果制得的阿霉素壳寡糖纳米粒呈球形或类球形,形态较为完整,平均粒径为(136.77±1.21)nm,表面电位为(20.53±0.31)m V,包封率为(56.99±1.40)%,载药量为(15.49±0.38)%,168 h的累积释放率为72.15%;阿霉素和载药纳米粒对MCF-7细胞增殖的抑制作用存在明显的浓度和时间依赖性,且载药纳米粒对MCF-7细胞增殖的抑制作用随时间增加而逐渐强于游离阿霉素。结论此方法制备的阿霉素壳寡糖纳米粒粒径较小,药物释放具有明显的缓释作用,并具有较好的抗肿瘤作用。     

汉黄芩素固体脂质纳米粒的制备及体外释放度考察

目的:制备汉黄芩素固体脂质纳米粒并对其体外释放度进行考察.方法:采用乳化分散-超声法制备汉黄芩素固体脂质纳米粒,以包封率和载药量为评价指标,进行正交试验筛选最优处方,并对最优处方的外观、粒径和体外释放度进行考察.结果:制得的纳米粒为均一球形,平均粒径为(153 ±34)nm,其平均载药量为(60.53±2.17)％,平均包封率为(85.54±4.16)％,48 h累积释放达80％.结论:本试验获得了较理想的汉黄芩素固体脂质纳米粒,其体外释放具有缓释作用.     

载氟尿嘧啶纳米粒的制备及SGC-7901胃癌细胞株的摄取实验

目的:制备载氟尿嘧啶的纳米粒,并考察其体外释放性能和胃癌细胞株对其的摄取能力。方法:以聚乙二醇单甲醚-聚乳酸乙醇酸-聚赖氨酸-(缬氨酸-精氨酸-甘氨酸-天冬氨酸-谷氨酸)环肽(PEAL-cRGD)为载体,用乳化-溶剂蒸发法制备氟尿嘧啶纳米粒,以粒径和包封率为评价指标,通过正交试验设计筛选最优制备工艺,并测定SGC-7901胃癌细胞株对该纳米粒的摄取能力。结果:以最优工艺制备的纳米粒为大小均匀的球形,粒径(172.9±2.3)nm,包封率(75.31±1.91)%,在pH7.4磷酸盐缓冲液中192h累积释放率为(58.63±2.47)%。SGC-7901胃癌细胞株能有效摄取该纳米粒。结论:本研究制备的氟尿嘧啶纳米粒包封率较高,粒径较小,能促进胃癌细胞对氟尿嘧啶的摄取。     

无稳定剂修饰的汉防己甲素PLGA纳米粒制备及体外评价

目的:制备无稳定剂修饰的汉防己甲素PLGA纳米粒,研究其理化性质及细胞毒和细胞摄取特性。方法:以聚乳酸-羟基醋酸共聚物(PLGA)为载体材料,采用无稳定剂修饰的纳米沉淀法制备汉防己甲素纳米粒;通过单因素试验考察不同制备工艺对纳米粒理化性质的影响;通过载药量、包封率、累积释药量等指标考察其载药特性;采用MTT比色法检测其对人肺腺癌细胞株A549的细胞毒性;采用共聚焦显微镜技术考察其细胞摄取特性。结果:无稳定剂修饰的汉防己甲素PLGA纳米粒平均粒径169.3 nm,与有稳定剂的汉防己甲素PLGA纳米粒相比外观无明显改变。在一定范围内,随着PLGA用量的增加,纳米粒的粒径呈上升趋势;随着投药量的增加,纳米粒的载药量显著增加,包封率下降。在pH7.4的释放介质中,纳米粒释慢释药,96 h累积释药率60.44%。细胞毒试验显示,当培养时间为8 h时,汉防己甲素组的细胞毒性大于汉防己甲素纳米粒组;当培养时间延长至24 h时,汉防己甲素纳米粒组的细胞活性明显低于纯药物组;高剂量的空白纳米粒组始终表现较低的细胞毒性。激光共聚焦电镜断层扫描显示汉防己甲素纳米粒能够较好的被细胞摄取。结论:制备的无稳定剂修饰的汉防己甲素PLGA纳米粒大小均一,包封率高,体外释药表现出较好的缓释效果,易被细胞摄取,对A549细胞的增殖有明显的抑制作用。     

载柚皮素壳聚糖纳米粒的制备及其体外细胞评价

目的：制备柚皮素壳聚糖纳米粒,初步探讨其对人肺腺癌细胞A549的细胞毒性和细胞摄取。方法：以壳聚糖和鱼精蛋白作为载体材料,采用离子胶凝法制备柚皮素壳聚糖纳米粒,透射电镜（TEM）观察其形态,马尔文激光粒度仪测定其粒径、分散度（PDI）和Zeta电位,离心法测定其包封率和载药量,采用恒温振荡水浴法对柚皮素壳聚糖纳米粒进行体外释放度研究,最后采用人肺癌细胞系A549细胞进行了细胞毒性、细胞摄取研究。结果：柚皮素壳聚糖纳米粒为球形或类球形粒子,结构完整,大小均一、球形度好,分散均匀,PDI、粒径、Zeta电位和包封率分别为0.268,139 nm、+15.7 mV和83.34%,柚皮素壳聚糖纳米粒体外释放呈缓释,24 h累积释放量达到了80%以上,体外释药过程用Higuchi方程拟合较好。MTT试验显示不同浓度的壳聚糖纳米粒和细胞作用72 h后,细胞活力均大于95%,本文所制备的壳聚糖纳米粒无细胞毒性。细胞摄取试验表明载FITC的壳聚糖纳米粒和A549细胞作用3 h后,可明显看到大量带绿色荧光的纳米粒穿过细胞膜进入细胞。结论：离子凝胶法成功制得粒径较小的柚皮素壳聚糖纳米粒,具有缓释性好,毒性小,壳聚糖纳米粒摄取率较高,可大大提高药物的利用率,具有广泛的应用前景。     

青蒿琥酯纳米粒的制备及其体外细胞抑制试验

目的:制备青蒿琥酯纳米粒,并对其性质及体外细胞抑制作用进行研究。方法:以聚乳酸-羟基乙酸共聚物(PLGA)为载体,采用自乳化方法制备青蒿琥酯纳米粒。扫描电镜观察纳米粒的形态,激光粒度仪测定纳米粒的粒径及其分布;考察纳米粒的载药量、包封率、体外释放情况;MTT法考察纳米粒对人白血病细胞株K562在不同时间(24、48、72h)的体外细胞抑制率,并与青蒿琥酯(原料药)比较。结果:所制青蒿琥酯纳米粒为圆球形,表面光滑,平均粒径为(144±3.0)nm,Zeta电位是-31.5mV,平均载药量和包封率分别为14%、84%;体外释放试验前期有明显突释现象,前24h累积释放度为46%,其后释放均匀,120h累积释放度达65%,具有缓释作用;其在72h时对细胞抑制率高于青蒿琥酯组(76.4%vs.59.1%),有较强抑制作用(P<0.05)。结论:所制青蒿琥酯纳米粒在体外具有较好的缓释性,对K562细胞有较强的抑制作用。     

乙酰半胱氨酸纳米粒的制备及体外释放研究

目的制备乙酰半胱氨酸纳米粒,并对其进行体外释放的研究。方法溶剂扩散法制备乙酰半胱氨酸纳米粒,单因素考察了壳聚糖浓度、油相中乙醇浓度、油水相比例对乙酰半胱氨酸纳米粒形态、大小、包封率的影响,通过透析袋法研究乙酰半胱氨酸纳米粒体外释药过程。结果经筛选得到形成纳米粒的最佳工艺为壳聚糖浓度2mg.min-1、乙醇浓度25%、油水相比为10∶1。该工艺制备纳米粒大小圆整,粒径为163±12.8nm,包封率达81%。体外释放结果表明,乙酰半胱氨酸纳米粒具有一定的缓释作用,药物在24h累积释放74.5%。结论溶剂扩散法制备乙酰半胱氨酸纳米粒方法简便、药物包封率高,该纳米粒是一种比较理想的乙酰半胱氨酸新剂型。     

抗癫疒间肽纳米粒的制备及体外释药性能的研究

目的制备抗癫疒间肽纳米粒,并研究其体外释药性能。方法选用聚乙二醇-聚乳酸-聚乙醇酸嵌段共聚物为载体,采用复乳-溶剂挥发法制备抗癫疒间肽纳米粒,以包封率、载药量等指标优化制备工艺,并研究纳米粒体外释药性能。结果抗癫疒间肽纳米粒外观呈圆形或类圆形,平均粒径为(100.2±2.45)nm,包封率和载药量分别为(64.46±1.34)%和(4.73±0.32)%,体外释药呈现缓释和突释两个阶段,符合Weibull方程。结论建立的制备工艺简便可行,得到的抗癫疒间肽纳米粒包封率和载药量较高,粒径小,体外释药具有明显的缓释特征。     

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.     

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.     

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.

     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

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.