姜黄素聚合物胶束的制备及抗肿瘤活性评价

目的:制备姜黄素的维生素E聚乙二醇琥珀酸酯(TPGS)聚合物胶束,从而改善姜黄素的水溶性和抗肿瘤活性。方法:以TPGS为载体材料,采用薄膜水化法制备姜黄素胶束;以包封率和粒径为指标,考察水化温度、水化时间、药载比和水化体积的影响;以包封率、粒径、载药量为指标,经四因素三水平正交试验,确定姜黄素/TPGS胶束的最佳制备工艺;考察姜黄素/TPGS胶束的体外释放度;利用MTT法测试姜黄素/TPGS的体外抗肿瘤活性。结果:姜黄素/TPGS胶束的最佳药载比为1∶40,水化温度为60℃,水化时间为30 min,水化体积为6 mL;所得胶束平均粒径为11.02 nm, Zeta电位为-11.31,载药量为2.65%,包封率为96.20%;姜黄素/TPGS 48 h体外累积释放率为78%,具有一定的缓释性;MTT法表明,姜黄素/TPGS具有良好的抗肿瘤活性。结论:该文采用薄膜水化法制备了一种稳定的姜黄素/TPGS胶束,改善了姜黄素的水溶性,明显提高了其抗肿瘤效果。     

pH敏感聚(2-乙基-2-噁唑啉)-壳聚糖-阿霉素共聚物胶束的制备及性质考察

目的合成pH敏感两亲性接枝共聚物聚(2-乙基-2-噁唑啉)-壳聚糖-阿霉素(PEOz-g-CS-HyzDOX),采用透析法制备阿霉素pH敏感两亲性共聚物胶束并对其相关的制剂学性质、细胞抑制及细胞摄取行为进行考察。方法分别利用透射电镜(TEM)、动态光散射法(DLS)和zeta电位分析仪对胶束的形态、粒径和表面电位进行表征;采用透析法考察载药聚合物胶束的体外释放行为;采用MTT法考察聚合物胶束的细胞抑制作用。结果反应产物使用红外及核磁表征,确定为目标产物;PEOz-g-CS-Hyz-DOX聚合物胶束载药量为4.2%。采用透析法制备的载阿霉素聚(2-乙基-2-噁唑啉)-壳聚糖丁二酸单甲酯胶束(PEOz-g-CSMS/DOX)载药量可达5.62%,包封率为59.35%;两种胶束的粒径均较小且粒径分布很窄,胶束粒子为类球形且分散良好;两种胶束释药行为体现pH敏感性;PEOz-g-CS-Hyz-DOX聚合物胶束体外细胞毒作用及细胞摄取均优于PEOz-g-CSMS/DOX胶束和阿霉素溶液。结论以壳聚糖为载体的化学腙键释药胶束作为抗肿瘤药物的药物传递系统具有可行性及良好的应用前景。     

熊果酸/PF127/TPGS-多柔比星混合纳米胶束的制备及其体外释药特性研究

目的:制备熊果酸(UA)/Pluronic F127(PF127)/聚乙二醇维生素E琥珀酸酯(TPGS)-多柔比星(DOX)混合纳米胶束,并对其进行表征和体外释药特性研究。方法:采用薄膜水化法制备UA/PF127/TPGS纳米胶束;以UA包封率为指标,结合单因素试验结果,通过L9(34)正交试验设计对处方中的UA投药量、PF127与TPGS的摩尔比、水化温度、水化体积进行优化并验证。在琥珀酰化TPGS的基础上,合成TPGS-DOX,与UA/PF127/TPGS混合制备UA/PF127/TPGS-DOX混合纳米胶束,考察其外观、粒径、临界胶束浓度(PF127/TPGS),采用透析袋扩散法考察其体外释药行为。结果:UA/PF127/TPGS纳米胶束的最优制备工艺为UA投药量8 mg、PF127与TPGS的摩尔比3∶7、水化温度50℃、水化体积4 mL,所得纳米胶束中UA的平均包封率为89.00%(RSD=0.43%,n=3)。在此基础上所制UA/PF127/TPGS-DOX混合纳米胶束溶液澄清且带有乳光;呈类球形且大小均匀,平均粒径为(115.00±9.42)mm;PF127/TPGS(摩尔比3∶7)的临界胶束浓度为0.001 3%。该混合纳米胶束中UA、DOX的体外释放均较其原料药或对照品明显减缓,胶束中两种药物的释药过程均符合Weibull方程。结论:本研究成功制备了UA/PF127/TPGS-DOX混合纳米胶束,其粒径均匀且系统稳定性好,并具有较好的缓释效果。     

还原响应型透明质酸抗肿瘤胶束的构建及其体外性质研究

目的合成透明质酸-胱胺-硬脂酸(HA-CYS-SA)两亲性聚合物,并研究其所制备胶束的理化性质、还原敏感性以及体外抑瘤效果。方法以碳二亚胺作为偶联剂,使胱胺、硬脂酸先后与透明质酸发生酰胺偶联反应,制得载体聚合物并通过核磁共振波谱法确定其结构。采用改进的探头超声法制备载多西他赛的聚合物胶束,以芘荧光法测定其临界胶束浓度,动态光散射法测定胶束的粒径分布,透射电镜观察胶束的微观形态;通过对载药胶束在不同谷胱甘肽浓度下的粒径变化与药物释放行为的考察,验证胶束的还原敏感性;通过激光共聚焦显微镜研究载药胶束的细胞摄取能力,并对载药胶束的体外抑瘤效果进行考察。结果成功制得两亲性聚合物材料,胶束粒子呈规则的球形,粒径为(186.7±5.3)nm;制备的载药胶束具有良好的还原敏感响应性,在无谷胱甘肽或10μmol·L~(-1)谷胱甘肽存在时,胶束的粒径在24 h内无明显变化;而在10及20 mmol·L~(-1)谷胱甘肽存在时,24 h后胶束的粒径分别增大了1.53倍和1.89倍,多西他赛的释放量分别提升了约43%及84%。包载荧光染料香豆素6的HA-CYS-SA胶束组的荧光强度明显高于游离香豆素6组,证明其具有更好的细胞摄取能力;载药胶束对4T1细胞的半数抑制浓度为0.304μg·m L~(-1),说明其具有显著的体外抗肿瘤效果。结论所构建的还原敏感型胶束具有良好的理化性质、还原敏感响应性、细胞摄取能力以及抑瘤效果,是极具应用潜力与发展前景的药物载体。     

载多西紫杉醇的F3多肽靶向单分子胶束的制备和体外评价

目的：制备载多西紫杉醇的F3多肽靶向单分子胶束（DTX/PAMAM-PLA-PEG-F3）,并对其进行体外评价。方法：所制备的单分子胶束采用动态光散射仪和透射电镜测定其粒径分布和形态;采用高效液相色谱法测定单分子胶束的载药量和评估其体外释药特性;采用MTT法考察单分子胶束的抗肿瘤活性;采用流式细胞仪和共聚焦显微镜探究细胞摄取胶束机制。结果：制备的单分子胶束呈球形,平均粒径（32.0±5.8） nm,载药量（12.4±1.3）wt.%;体外释药研究表明制备的单分子胶束具有pH响应性;与非靶向胶束组相比,靶向胶束组的对乳腺癌MDA-MB-231细胞的细胞毒性更高,细胞摄取效率加强,靶向配体F3多肽可介导肿瘤细胞特异性摄取靶向单分子胶束。结论：DTX/PAMAM-PLA-PEG-F3作为纳米药物载体在提高抗肿瘤疗效方面具有广阔的应用前景。     

姜黄素纳米胶束的制备及体外抗肿瘤作用研究

目的 制备姜黄素(Cur)/甲氧基聚乙二醇-聚己内酯(MP)载药纳米胶束,并研究其体外抗肿瘤作用。方法 采用薄膜分散法制备Cur/MP纳米胶束,筛选不同药材质量比优化处方,在扫描电镜下观察载药纳米胶束的形态;采用CCK-8法考察Cur、Cur/MP胶束对人非小细胞肺癌A549细胞的抑制率;以香豆素6为荧光探针考察细胞对胶束的摄取行为。结果 按最优处方制备3批胶束的平均粒径为35.71±0.2 nm,平均电位为-16.8±0.2 mV,平均包封率为97.52%±1.00%,平均载药量5.25%±0.80%;Cur/MP胶束在72 h内释放度最大可达74.16%,释放缓慢,无突释现象,遵循一级动力学方程;与Cur溶液比较,Cur/MP纳米胶束对A549细胞的抑制作用增强;荧光显微镜下可观察到,随着时间的延长,细胞对药物的摄取增加。结论 Cur/MP胶束制备工艺简单,可增强药物对A549细胞的抑制作用;聚合物纳米胶束的pH敏感性有利于其在体内肿瘤组织中的蓄积及肿瘤细胞内的摄取。     

PEG-I-dC16 酸敏释药胶束的制备与体外评价

目的构建聚乙二醇-亚胺键-棕榈酸酯(PEG-I-d C16)酸敏释药纳米胶束,并考察载阿霉素胶束在体外的抗肿瘤活性及药物被细胞摄取的情况。方法通过透析法制备载阿霉素胶束,采用紫外法测定胶束的载药量和包封率,并用粒度仪测定其粒径和Zeta电位。进一步采用MTT法测定其体外抗肿瘤活性,用流式细胞仪测定其细胞摄取量,并用激光共聚焦观察细胞核内的药物蓄积量。结果分子量为2000的PEG胶束的载药量和包封率分别为(12.7±1.1)%和(49.8±2.2)%,平均粒径为(72.3±2.5)nm。酸敏释药胶束的细胞药物摄取量与细胞毒性均高于非酸敏释药胶束,且在细胞核的药物蓄积量也比非酸敏胶束高,差异均具有统计学意义(P<0.05)。结论 PEG-I-d C16酸敏释药胶束可增加细胞或细胞核对阿霉素的摄取量,提高其体外抗肿瘤效果,为开发肿瘤靶向给药系统提供了研究基础。     

基于TPGS的紫杉醇自微乳的制备及其评价

目的:制备基于P-糖蛋白抑制剂D-α-生育酚聚乙二醇琥珀酸酯(TPGS)的紫杉醇自微乳(PTX-T-SMEDDS),以增强耐药肿瘤细胞对PTX的敏感性。方法:采用伪三元相图法筛选TPGS自微乳(T-SME)的制备处方;以粒径、多分散指数(PDI)和PTX包封率为指标筛选PTX-T-SMEDDS的制备条件;利用马尔文粒径仪和透射电镜表征PTX-T-SMEDDS乳化后的粒径、Zeta电位、PDI和形态,并利用高效液相色谱(HPLC)测定药物包封率,考察PTX-T-SMEDDS的体外释药行为和稳定性;以非小细胞肺癌紫杉醇耐药株A549/Taxol为模型,采用MTT法评价细胞毒性。结果:T-SME的最终处方为维生素E 20%,TPGS 40%,异丁醇40%。在PTX与维生素E/TPGS/异丁醇的质量比为1∶120时制得PTX-T-SMEDDS,其乳化后的粒径为(20.64±0.23) nm,乳滴形态为类圆形,PTX包封率为(85.10±3.05)%。相较于游离PTX,PTX-T-SMEDDS呈缓慢释药行为。PTX-T-SMEDDS具有较好的贮存稳定性、稀释稳定性和离心稳定性。PTX-T-SME...     

紫杉醇Pluronic P105聚合物胶束的制备、表征与逆转肿瘤多药耐药性的体外研究

药物递送系统是克服肿瘤多药耐药性(MDR)的一种新策略。本文以聚合物胶束系统和难溶性药物紫杉醇(PTX)为研究对象，旨在制备一种新型的PTX给药系统，既能增溶难溶性药物，又具有克服肿瘤MDR的能力。以Pluronic P105为载体，采用固体分散-水化法制备PTX聚合物胶束，并以星点设计-效应面优化法进行处方优化。对其粒径、体外释放等性质进行表征后，以人耐药卵巢癌细胞SKOV-3/PTX为细胞模型，体外评价PTX聚合物胶束的细胞摄取及其逆转肿瘤细胞耐药性的作用。结果显示，聚合物胶束制剂的载药量约为1.1%、药物浓度约为700 μg·mL^-1、平均粒径约为24 nm。胶束制剂与普通制剂(Taxol)在6 h内的累积释放分别为45.4%和95.2%，前者具有较强的缓释作用；胶束制剂与Taxol对SKOV-3/PTX的IC₅₀值分别为1.14和5.11 μg·mL^-1，二者的耐药逆转指数(RRI)分别为9.65和2.15。胶束制剂可促进耐药细胞对P-糖蛋白(P-gp)底物(PTX或Rhodamine-123)的摄取。结果表明，Pluronic P105可有效增溶难溶性药物PTX，并形成具有较强缓释作用的纳米级聚合物胶束制剂，该制剂可显著提高PTX对人卵巢癌耐药细胞的细胞毒性，能逆转其耐药性。     

载喜树碱普郎尼克/TPGS混合胶束的制备与质量评价

目的制备装载喜树碱的普朗尼克105和维生素E琥珀酸聚乙二醇酯(TPGS)混合胶束,并对其性质及体外释药特性进行评价。方法根据两种材料的比例选择4个处方,采用薄膜形成法制备混合胶束;透射电镜观察聚合物胶束形态;激光动态散射法测定胶束的粒径及其分布;荧光分光光度法考察含药胶束的载药量,确定最佳处方;透析袋法进行胶束体外释药行为研究。结果混合胶束大小均匀,具有球形核-壳结构,粒径分布范围在4~9 nm,并且随着维生素E琥珀酸聚乙二醇酯用量的增加,聚合物胶束的粒径分布更加集中;混合胶束显著提高了喜树碱的溶解度;喜树碱混合胶束体外释放缓慢,符合双向动力学特征。结论普朗尼克105和维生素E琥珀酸聚乙二醇酯混合胶束可以作为疏水性药物的纳米级长循环载体,具有很好的应用前景。     

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.

---

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.     

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.     

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.     

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.