不同表面活性剂对两性霉素B脂质体体内外性质的影响

目的寻找与DSPE-PEG功能相似的表面活性剂修饰两性霉素B脂质体，以增加其在体内的稳定性，改善其体内分布，降低毒副作用。方法用薄膜超声法制备两性霉素B脂质体；比较用DSPE-PEG，Tween 80和Brij 35修饰后两性霉素B脂质体包封率、粒径分布、稳定性及组织分布的变化。结果两性霉素B脂质体的包封率最高为（91.2±1.6）％。修饰后的两性霉素B脂质体包封率提高，粒径减小，稳定性增加，肝、脾和肾中两性霉素B的浓度降低，脑中AmB的浓度提高。结论DSPE-PEG和Brij 35能提高脂质体逃避网状内皮系统吞噬的能力；Tween 80能增加两性霉素B在大鼠脑组织中的分布。     

两性霉素B脂质体的制备及药动学

目的:制备两性霉素B脂质体并对其药动学进行研究。方法:采用有机溶剂注入法制备两性霉素B脂质体,用微射流进行整粒,用动态光散射法测定粒径,采用Ultrafree-CL离心超滤管分离游离两性霉素B(F-AMB)与复合两性霉素B(L-AMB)检测包封率,用Wistar大鼠进行药动学研究。结果:两性霉素B脂质体平均粒径为(115±20)nm;包封率>99.9%;大鼠静脉注射,实验药与Amphotec的Cmax,AUC0~168 h和AUC0~∞无显著性差异(P>0.05)。结论:采用有机溶剂注入法制备两性霉素B脂质体具有较高包封率,在大鼠体内的药动学特征与Amphotec一致。     

挤压器联动装置制备两性霉素B脂质体

目的考察挤压器联动装置制备两性霉素B脂质体制剂的稳定性。方法使用联动装置制备两性霉素B脂质体,用透析法检测两性霉素B脂质体的药物包封率,粒径仪器跟踪脂质体制剂的粒径及其分布,测定稳定性、泄漏率及毒性。结果所用联动装置可使脂质体的制备工艺简化,投料成品一步完成,同时可在线监控粒径。采用此装置制备的两性霉素B脂质体的粒径显著小于手动方式所制备,且粒径分布较窄;药物包封率为97．3％。通过与手动方法制备的脂质体制剂的多项技术指标对比,表明采用联动装置制备的两性霉素B脂质体制剂的药物包封率高,制剂稳定性好,药物渗漏率低。结论挤压器联动装置可用于工业化生产两性霉素B脂质体制剂的产品质量稳定、可控。     

RMP-7及其衍生物对脂质体跨血脑屏障作用的影响

目的研究RMP-7及其衍生物对脂质体跨血脑屏障的促进作用。方法测定RMP-7与DSPE-PEG-NHS偶联的物质的量比；用血脑屏障的体外模型验证其生物活性；观察脑组织切片中伊文思蓝的荧光位置和强度，测定脑组织中伊文思蓝的浓度。结果RMP-7与DSPE-PEG-NHS偶联物质的量比为1∶1；RMP-7和DSPE-PEG-RMP-7能使过氧化合物酶跨血脑屏障体外模型的转运速率增加2～3倍，修饰脂质体后能使所包封的伊文思蓝在脑中的浓度增加。结论RMP-7与DSPE-PEG-RMP-7对脂质体跨血脑屏障均有促进作用，且后者效果更好。     

两性霉素B脂质体治疗隐球菌性脑膜炎疗效观察

目的:对比观察两性霉素B(AMB)和AMB脂质体治疗新型隐球菌性脑膜炎(隐脑)的临床疗效及不良反应.方法:将22例隐脑患者随机分为AMB组和AMB脂质体组,分别给予AMB及AMB脂质体静脉滴注,部分患者加AMB鞘内注射,按标准评定疗效和不良反应.结果:患者可以较好地耐受两性霉素B脂质体静脉滴注及鞘内注射,AMB脂质体发生不良反应的几率及严重程度明显低于普通AMB.结论:两性霉素B脂质体治疗新型隐脑优于普通AMB.     

两性霉素B长循环脂质体冻干剂的制备工艺研究

目的:对两性霉素B长循环脂质体的冻干工艺进行研究,制备两性霉素B长循环脂质体的冻干剂.方法:采用薄膜-超声法制备了两性霉素B长循环脂质体混悬液.以冻干品再分散后的粒径、包封率为评价指标,考察了不同种类的冻干保护剂和浓度对脂质体冻干品的影响,并对冻干工艺参数进行了优化.结果:选择海藻糖为冻干保护剂,冻干效果较好.制备的冻干剂的平均粒径为(116.8±1.6)nm,药物包封率为(76.0±1.9)%.结论:通过冻干保护剂的筛选和优化冻干工艺参数可以获得最佳的两性霉素B长循环脂质体的冻干品.     

神经生长因子脂质体跨血脑屏障体内外研究神经生长因子脂质体跨血脑屏障体内外研究

目的研究神经生长因子（nerve growth factor,NGF）脂质体在体外血脑屏障（blood-brain barrier,BBB）模型上的通透性以及在体内脑组织的分布，并对体内外结果进行相关性分析。方法用小鼠脑微血管内皮细胞(BMVEC)建立的BBB体外实验模型，研究NGF脂质体在体外模型上的通透率；¹²⁵I-NGF和SDS-PAGE法联合使用研究NGF脂质体在脑组织的分布。结果NGF脂质体的最高包封率为34%，平均粒径小于100 nm。脂质体能够增加NGF在BBB模型上的通透率，以NGF-SSL-T为最大。脑组织药物浓度次序为NGF-SSL-T>NGF-SSL+RMP-7>NGF-SSL。体内外结果具有良好相关性。结论脂质体能够增加NGF跨越BBB的能力，RMP-7偶联在脂质体上（NGF-SSL-T）效果好于RMP-7与脂质体的简单混合（NGF-SSL+RMP-7）。     

两性霉素B及其卵磷脂-胆固醇脂质体降解动力学研究

目的考察以卵磷脂、胆固醇为膜材制备的两性霉素B脂质体的稳定性及降解动力学。方法应用高效液相色谱法考察光和热对两性霉素B溶液及其脂质体中药物稳定性及降解动力学的影响,并拟合其降解动力学模型,求算降解半衰期。结果两性霉素B溶液及其脂质体光降解分别符合一级和零级动力学过程,降解半衰期分别为2.6和24.7d;热降解过程分别符合零级动力学和Higuchi方程;40℃下半衰期分别为27.8和1532.8d;60℃下半衰期分别为8.2和17.9d。结论脂质体可明显降低两性霉素B的光和热降解,延长药物降解半衰期,显著提高两性霉素B的稳定性。     

两性霉素B磁性脂质体的制备与质量控制

目的:制备稳定的两性霉素B磁性脂质体。方法:采用薄膜分散加超声法制备了两性霉素B磁性脂质体。以影响磁性脂质体稳定性和均匀度的两性霉素B浓度、卵磷脂与胆固醇用量比、磁性液体加入量及超声条件为考察因素,进行正交试验,以磁性脂质体溶液的均匀度和稳定性为考察指标,以溶液的状态、溶液的沉淀量和放置保存时沉淀量的增加量为评分标准对处方进行了筛选。建立了两性霉素B磁性脂质体的紫外分析方法。结果:按正交试验设计最优组合制备的磁性脂质体回收率为100.75%;包封率为76.07%。两性霉素B的线性范围为1~10mg.L-1,回归方程A=0.1547C 0.003,r=0.9998。结论:采用薄膜分散加超声法,用正交试验法筛选处方能够制备稳定的磁性脂质体溶液。     

两性霉素B脂质体-微球的制备及工艺优化

目的 应用Box-Behnken响应面分析法优化两性霉素B脂质体-微球的制备条件。方法 采用乳化-相分离法制备包载两性霉素B脂质体的海藻酸钠微球,通过单因素实验确定显著影响微球成球性的因素,利用Box-Behnken响应面分析法考察氯化钙浓度、司盘80用量及搅拌速度对微球粒径、跨距、包封率、1h释放量及72h释放量的影响,筛选最佳制备工艺,并进行体外抑菌试验。结果 最佳制备工艺条件为氯化钙浓度41%,司盘80用量4.3%,搅拌速度678r/min。此优化条件下,制得的两性霉素B脂质体-微球平均粒径为8.0μm,药物包封率大于80%,体外抑菌试验结果显示载药微球具有较好的抑菌能力。结论 Box-Behnken响应面分析法可有效平衡各因素之间的相互影响,适用于两性霉素B脂质体-微球的制备工艺筛选。     

The study on brain targeting of the amphotericin B liposomes

To improve transporting drugs across the Blood Brain Barrier (BBB) into the brain, RMP-7 was conjugated to the surface of liposomes containing Amphotericin B (AmB) for cerebral inflammation, because it can selectively bound to the B2 receptors on the capillary blood vessel. First, RMP-7 was conjugated to DSPE-PEG-NHS [1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly (ethylenegly-col)]-hydroxy succinamide, PEG M 3400] under mild condition to obtain a predominantly 1:1 conjugate (DSPE-PEG-RMP-7), as evidenced by the Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS). The second, endothelium cell was cultured on the cell insert to form an in vitro BBB model and the stereoscan microscope, electric resistance and permeation of horse-radish peroxidase (HRP) across the endothelium cell monolayer were used as indicators to evaluate the integrality of the monolayer, and then the in vitro BBB model was used to determine the bioactivity of DSPE-PEG-RMP-7 "opening" BBB. The results demonstrated the in vitro BBB model was set up, RMP-7 and DSPE-PEG-RMP-7 could improve the transporting of HRP across the BBB. The third, the liposomes containing AmB (AmB-L-PEG) was prepared by modified Film-sonication method and DSPE-PEG-RMP-7 was used to modify the AmB-L-PEG to obtain AmB-L-PEG-RMP-7. The fourth, tissue distribution of AmB in the rats of three groups was determined: Group I, AmB-L-PEG; Group II, AmB-L-PEG+RMP-7 (the physical mixture of AmB-L-PEG and RMP-7); Group III, AmB-PEG-RMP-7. The drugs were transfused into the rats through the femoral vein. The concentration of AmB in the tissue was checked using High-Performance Liquid Chromatography (HPLC) method. The rank of AmB concentration in the brain were as follows: III>II>I. The AmB concentration in the liver, spleen, lung and kidney had no significant difference. The concentration of AmB in the brain of the group III was raised several times higher than that in the other two groups, because the DSPE-PEG-RMP-7 had been inserted in the surface of AmB-L-PEG. Both the RMP-7 and AmB-L-PEG could reach BBB at the same time. When RMP-7 selectively reacted with the B2 receptor, the BBB is "opened" and AmB was transported into the brain at the same time. While in group II, the RMP-7 could improve the AmB concentration in the brain a little, because the RMP-7 and liposomes could not reach BBB at the same time. The distribution of AmB in the tissues demonstrated that the RMP-7 and its derivative had selectivity to the brain.     

The Study on Brain Targeting of the Amphotericin B Liposomes

To improve transporting drugs across the Blood Brain Barrier (BBB) into the brain, RMP-7 was conjugated to the surface of liposomes containing Amphotericin B (AmB) for cerebral inflammation, because it can selectively bound to the B2 receptors on the capillary blood vessel. First, RMP-7 was conjugated to DSPE-PEG-NHS [1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly (ethylenegly-col)]-hydroxy succinamide, PEG M 3400] under mild condition to obtain a predominantly 1:1 conjugate (DSPE-PEG-RMP-7), as evidenced by the Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS). The second, endothelium cell was cultured on the cell insert to form an in vitro BBB model and the stereoscan microscope, electric resistance and permeation of horse-radish peroxidase (HRP) across the endothelium cell monolayer were used as indicators to evaluate the integrality of the monolayer, and then the in vitro BBB model was used to determine the bioactivity of DSPE-PEG-RMP-7 "opening" BBB. The results demonstrated the in vitro BBB model was set up, RMP-7 and DSPE-PEG-RMP-7 could improve the transporting of HRP across the BBB. The third, the liposomes containing AmB (AmB-L-PEG) was prepared by modified Film-sonication method and DSPE-PEG-RMP-7 was used to modify the AmB-L-PEG to obtain AmB-L-PEG-RMP-7. The fourth, tissue distribution of AmB in the rats of three groups was determined: Group I, AmB-L-PEG; Group II, AmB-L-PEG+RMP-7 (the physical mixture of AmB-L-PEG and RMP-7); Group III, AmB-PEG-RMP-7. The drugs were transfused into the rats through the femoral vein. The concentration of AmB in the tissue was checked using High-Performance Liquid Chromatography (HPLC) method. The rank of AmB concentration in the brain were as follows: III>II>I. The AmB concentration in the liver, spleen, lung and kidney had no significant difference. The concentration of AmB in the brain of the group III was raised several times higher than that in the other two groups, because the DSPE-PEG-RMP-7 had been inserted in the surface of AmB-L-PEG. Both the RMP-7 and AmB-L-PEG could reach BBB at the same time. When RMP-7 selectively reacted with the B2 receptor, the BBB is "opened" and AmB was transported into the brain at the same time. While in group II, the RMP-7 could improve the AmB concentration in the brain a little, because the RMP-7 and liposomes could not reach BBB at the same time. The distribution of AmB in the tissues demonstrated that the RMP-7 and its derivative had selectivity to the brain.     

The effect of RMP-7 and its derivative on transporting Evans blue liposomes into the brain

To investigate the effect of RMP-7 and its derivative on drug transport across blood brain barrier (BBB), RMP-7 and DSPE-PEG-NHS [1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethyleneglycol)]-hydroxy succinamide, PEG M 3400] were conjugated under mild conditions and the reaction ratio was determined using MALDI-TOF-MS (matrix-assisted laser desorption-ionization time-of-flight mass spectrometry). An endothelial cell monolayer in vitro BBB model was established and used to determine the bioactivity of RMP-7 and its derivative “opening BBB.” Horse radish peroxide (HRP), liposome (HRP-L-PEG), and Evens blue (EB) liposome (EB-L-PEG) were prepared using the reverse-phase evaporation method. HRP-L-PEG-RMP-7 and EB-L-PEG-RMP-7 were obtained by inserting DSPE-PEG-RMP-7 into the surface of liposome. The bioactivity of RMP-7 and DSPE-PEG-RMP-7 opening BBB were evaluated to determine their effect on the permeation ratio of HRP and HRP liposome across the in vitro BBB model. To evaluate the in vivo bioactivity of RMP-7 and DSPE-PEG-RMP-7 on EB transport across BBB into the brain, the indicated compounds were administered to rats. Then, brain slices were analyzed using confocal laser scanning microcopy and the EB concentration in the brain, liver, spleen, lung, and kidney was determined using the formamide-extraction-ultraviolet-spectrophotometric method. The results demonstrated that RMP-7 was conjugated with DSPE-PEG-NHS at the molecular ratio of 1:1 and the product is DSPE-PEG-RMP-7. Compared with adding HRP alone, RMP-7 and DSPE-PEG-RMP-7 improved 2- to 3-fold the transport of HRP in the in vitro BBB model. The in vivo experiments showed that DSPE-PEG-RMP-7 was better at facilitating EB transport into brain than RMP-7. The reason may be that DSPE-PEG-RMP-7 can “open BBB” as soon as the EB-L-PEG-RMP-7 reaches BBB.     

Synergic anticandidal effect of epigallocatechin-O-gallate combined with amphotericin B in a murine model of disseminated candidiasis and its anticandidal mechanism

In the present study, we investigated synergic anticandidal effect of epigallocatechin-O-gallate (EGCG) in a murine model of disseminated candidiasis caused by Candida albicans. In addition, its mechanism was examined. In the animal system, EGCG-given BALB/c mice group intraperitoneally (i.p.) before intravenous (i.v.) inoculation with viable C. albicans yeast cells survived longer than diluent-received (control) mice group (p<0.05). EGCG treatment inhibited the hyphal formation from the yeast form of C. albicans, causing growth-inhibition of the candidal cells. In experiments determining synergic effect, mice given diluent (control), Amp B (amphotericin B; 0.5 mg/kg of body weight), or EGCG (2 mg/kg) had mean survival times (MST) of approximately 10.9, 11.7, and 13.9 d, respectively. However, mice administered combination of Amp B (0.5 mg/kg) plus EGCG (2 mg/kg) had a MST value of 42.1 d, surviving an average of app. 30 d longer than the Amp B alone-received mice groups. The MST value from the combination-treated mice groups was much greater than MST value from mice groups that received four times the Amp B dose. These results indicate that EGCG, which has anticandidal activity causing blockage of the hyphal formation, has the synergism combined with Amp B against disseminated candidiasis.     

The Effect of RMP-7 and its Derivative on Transporting Evens Blue Liposomes into the Brain

To investigate the effect of RMP-7 and its derivative on drug transport across blood brain barrier (BBB), RMP-7 and DSPE-PEG-NHS [1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethyleneglycol)]-hydroxy succinamide, PEG M 3400] were conjugated under mild conditions and the reaction ratio was determined using MALDI–TOF-MS (matrix-assisted laser desorption-ionization time-of-flight mass spectrometry). An endothelial cell monolayer in vitro BBB model was established and used to determine the bioactivity of RMP-7 and its derivative “opening BBB.” Horse radish peroxide (HRP), liposome (HRP-L-PEG), and Evens blue (EB) liposome (EB-L-PEG) were prepared using the reverse-phase evaporation method. HRP-L-PEG-RMP-7 and EB-L-PEG-RMP-7 were obtained by inserting DSPE-PEG-RMP-7 into the surface of liposome. The bioactivity of RMP-7 and DSPE-PEG-RMP-7 opening BBB were evaluated to determine their effect on the permeation ratio of HRP and HRP liposome across the in vitro BBB model. To evaluate the in vivo bioactivity of RMP-7 and DSPE-PEG-RMP-7 on EB transport across BBB into the brain, the indicated compounds were administered to rats. Then, brain slices were analyzed using confocal laser scanning microcopy and the EB concentration in the brain, liver, spleen, lung, and kidney was determined using the formamide–extraction–ultraviolet-spectrophotometric method. The results demonstrated that RMP-7 was conjugated with DSPE-PEG-NHS at the molecular ratio of 1:1 and the product is DSPE-PEG-RMP-7. Compared with adding HRP alone, RMP-7 and DSPE-PEG-RMP-7 improved 2- to 3-fold the transport of HRP in the in vitro BBB model. The in vivo experiments showed that DSPE-PEG-RMP-7 was better at facilitating EB transport into brain than RMP-7. The reason may be that DSPE-PEG-RMP-7 can “open BBB” as soon as the EB-L-PEG-RMP-7 reaches BBB.     

Ginkgo terpene component has an anti-inflammatory effect on Candida albicans-caused arthritic inflammation

The Ginkgo biloba extract, EGb 761, contains flavonoid glycosides and unique terpene lactones as major active components. In this study, we determined the anti-inflammatory effect of the water-soluble portion (GH415) of the EGb 761 on the inflammation caused by Candida albicans, a major ethiological agent that causes fungal arthritis. For inflammatory induction, an emulsified mixture of C. albicans cell wall and Complete Freund's Adjuvant (CACW/CFA) was injected into BALB/c mice by the hind footpad route once a day for 3 days. Twenty-four hours after the final injection, mice having the swollen footpad were given the GH415 (2 mg/dose) intraperitoneally to the mice once every 3 days for 15 days. The footpad-swelling of these mice was measured during the entire observation period. Results showed that the GH415 treatment reduced the swelling. In the same animal model, this effect was enhanced by treatment with the GH415 entrapped within liposome (Lipo-GH: 200 micro/dose). Further analysis revealed that terpene, not flavone portion, was responsible for such therapeutic anti-inflammatory effect. Treatment with the terpene (7.4 microg/dose) by liposomal delivery method had similar effects as the treatment with indomethacin at 30 microg/dose. Addition of the terpene to lipopolysaccharide-treated macrophages showed suppression of nitric oxide (NO) production. These results suggest that blockage of the NO production from the macrophages that infiltrated to the inflamed site may be a possible mechanism for the therapeutic anti-inflammatory effect.