基于分子对接技术的三元混合胶束对多西他赛的增溶效应及安全性

目的为提高抗肿瘤药物多西他赛的水溶性,制备磷脂-胆酸钠-Soluplus■三元混合胶束包载多西他赛,结合分子对接仿真技术研究三元混合胶束的结构及形成机制。方法采用薄膜分散法制备Soluplus?胶束、磷脂-胆酸钠二元混合胶束、磷脂-胆酸钠-Soluplus■三元混合胶束;采用芘荧光探针法测定不同胶束的临界胶束浓度值;测定不同混合胶束对多西他赛的最大增溶量;结合分子对接仿真技术对混合胶束结构进行研究;采用紫外分光光度法对不同类型胶束进行体外溶血安全性评价。结果芘荧光探针法测定临界胶束浓度结果表明不同胶束的形成能力为:Soluplus■胶束>三元混合胶束>二元混合胶束。三种胶束对多西他赛的增溶能力为:Soluplus■胶束>三元混合胶束>二元混合胶束。胶束结构研究结果表明,磷脂、胆酸钠与Soluplus■的对接结合能分别为-9.11和-5.12 kcal·mol^-1,主要以氢键和疏水作用与Soluplus■相结合,位于Soluplus■分子空穴中,离子效应得以屏蔽。体外溶血实验结果显示在磷脂-胆酸钠二元混合胶束中插入Soluplus■制备的三元混合胶束溶血安全性提高。结论在磷脂-胆汁盐-Soluplus■三元混合胶束中,高分子聚合物Soluplus■的加入使二元混合胶束的增溶量增加,溶血作用降低,安全性提高,这对于今后高低分子组合物组分对药物的增溶及保护作用具有重要参考意义。     

色胺酮纳米胶束的制备及其性质研究

目的制备色胺酮纳米胶束,改善色胺酮的水溶性,并进行体外性质考察。方法以二硬脂酰基磷脂酰乙醇胺-聚乙二醇2000(DSPE-PEG2000)为载体,用溶剂挥发法制备色胺酮纳米胶束,通过正交实验筛选制备胶束的最佳条件,核磁共振氢谱(1 HNMR)验证色胺酮包载于纳米胶束,用芘荧光探针法测定其临界胶束浓度(CMC),用紫外分光光度计测定其包封率和载药率,动态光散射法测定胶束的粒径,以粒径、外观形态和包封率为指标考察胶束的稳定性。结果色胺酮纳米胶束的CMC为8.93×10-6mol·L~(-1),色胺酮与聚合物投药比为0.442 9∶1(mol∶mol),真空干燥1h,水化5min时,胶束的包封率为32.24%±1.37%,载药率为5.468%±0.39%。色胺酮纳米胶束平均粒径为112.5nm,平均分散系数为0.208,4℃条件下胶束可稳定15d以上。结论制备色胺酮纳米胶束,将色胺酮的溶解度提高至1.625mmol·L~(-1),为改善色胺酮生物利用度的研究奠定了基础。     

冬凌草甲素长循环胶束的制备及药动学性质的考察

目的制备冬凌草甲素长循环胶束,对比普通冬凌草甲素磷脂/胆盐混合胶束和冬凌草甲素长循环胶束在大鼠体内的药动学差异。方法用薄膜分散法制备冬凌草甲素长循环胶束和普通冬凌草甲素磷脂/胆盐混合胶束,测定粒径,HPLC法测定血浆中冬凌草甲素的浓度,并用DAS2.0软件计算药动学参数。结果胶束粒径为14.53±1.19 nm,PDI为0.28±0.06。冬凌草甲素长循环胶束的体内T1/2为125.25±40.78 h,是普通胶束的12.8倍,AUC为168.04±39.01μg.L-1.h-1,为普通胶束的5.8倍(P<0.05)。结论所制备的冬凌草甲素长循环胶束与普通磷脂/胆盐混合胶束相比,其体内半衰期明显延长,生物利用度显著提高,具有长循环的效果。     

Preparation of long - circulating oridion - containing miceile and its pharmacokinetics

目的 制备冬凌草甲素长循环胶束,对比普通冬凌草甲素磷脂/胆盐混合胶束和冬凌草甲素长循环胶束在大鼠体内的药动学差异.方法 用薄膜分散法制备冬凌草甲素长循环胶束和普通冬凌草甲素磷脂/胆盐混合胶束,测定粒径,HPLC法测定血浆中冬凌草甲素的浓度,并用DAS2.0软件计算药动学参数.结果 胶束粒径为14.53±1.19 nm,PDI为0.28±0.06.冬凌草甲素长循环胶束的体内T1/2为125.25±40.78 h,是普通胶束的12.8倍,AUC为168.04±39.01 μg·L-1·h-1,为普通胶束的5.8倍(P＜0.05).结论 所制备的冬凌草甲素长循环胶束与普通磷脂/胆盐混合胶束相比,其体内半衰期明显延长,生物利用度显著提高,具有长循环的效果.     

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。     

应用混合胶束制备紫杉醇注射液

用吐温-80与大豆磷脂制备紫杉醇混合胶束注射液。用HPLC法考察载药胶束稀释3d内的稳定性；用荧光分析法测得空白胶束的临界胶束浓度（CMC）比吐温-80胶束低，微极性比聚氧乙烯蓖麻油注射液低。人与磷脂含量达120mg／ml的制品稀释后于室温放置3d，紫杉醇含量未见明显下降。     

多西他赛混合胶束的制备及其性能评价

目的为提高难溶性药物多西他赛的水溶性,制备多西他赛-聚乙烯己内酰胺-聚醋酸乙烯酯-聚乙二醇接枝共聚物(soluplus)-聚乙二醇-15-羟基硬脂酸酯(solutol HS15)混合胶束(docetaxel mixed micelles,DTX-MMs),并对其性质进行评价。方法以soluplus和solutol HS15作为两亲性载体材料,采用薄膜分散法制备DTX-MMs;利用马尔文激光粒度仪测定胶束的粒径及分布;采用透射电镜观察混合胶束的形态;采用高效液相色谱法测定混合胶束的包封率和载药量;采用芘荧光探针法测定混合胶束的临界胶束浓度;以自制多西他赛注射液为对照,比较两种制剂的体内外性质差异。结果由薄膜分散法制备的混合胶束的包封率和载药量分别为89.91%和4.658%,平均粒径为(72.54±2.2)nm,多分散系数为0.16±0.036;透射电镜下观察到混合胶束呈球形、分散良好;测得的临界胶束质量浓度值为(6.76×10~(-2))g·L~(-1);与多西他赛注射剂相比,混合胶束具有一定的缓释能力,无溶血现象,药时曲线下面积(AUC_(0-t))提高了2.638倍。结论采用薄膜分散法制备的混合胶束,粒径小,包封率高,稳定性好,可显著提高多西他赛在水中的溶解度,具有良好的体内外性能。     

注射用七叶皂苷钠脂质体制备工艺的研究及初步稳定性考察

目的 优化注射用七叶皂苷钠脂质体的制备工艺。方法 采用单因素考察法及Box-Behnken设计-响应曲面法,考察磷脂种类选择、药物与磷脂比例(W/W)、磷脂与胆固醇比例(W/W)、DSPE-mPEG2000用量、无水乙醇用量(W/V)、水相pH等因素对注射用七叶皂苷钠脂质体包封率的影响,优化其制备工艺,并通过透射电镜、粒径分布以及电位对脂质体进行质量评价。结果 药物在水合介质的质量浓度为2.5 mg·mL^-1,磷脂选用EPCS,药物与磷脂比例为1∶20,磷脂与胆固醇比例为3∶1,DSPE-mPEG2000用量为0.1%、无水乙醇用量为15%(W/V),水相pH为3.5。制备得到的注射用七叶皂苷钠脂质体具有高包封率(99.33%),粒径均一为(107.33±0.84) nm,多分散系数(PDI)为(0.130±0.017);Zeta电位为(-30.34±0.23) mv。结论 优化筛选的脂质体制备工艺简便、包封率高、稳定性好,适用于注射用七叶皂苷钠脂质体的制备。     

表面活性剂临界胶束浓度测定方法的建立和比较

目的：临界胶束浓度（Critical Micelle Concentration,CMC）是表面活性剂重要的功能性指标, 本文旨在建立一种适用于离子型和非离子型表面活性剂临界胶束浓度的快速准确的测定方法。方法：采用芘荧光光谱法测定不同类型表面活性剂CMC值,并将结果与传统表面张力法和电导率法结果相比较。 结果：芘荧光法测定不同种类表面活性剂CMC值重复性良好,其测定结果与经典的表面张力法和电导率法测定结果相比无显著性差异。结论：建立了重复性和准确度良好的芘荧光光谱法,该法操作简单、准确度高,可以替代表面张力法及电导率法测定表面活性剂的CMC值。     

蓝萼甲素自组装纳米胶束的制备与性质研究

摘要目的制备蓝萼甲素自组装纳米胶束,并考察其性质。方法以三嵌段聚合物聚酯 聚乙二醇（PLGA PEG PLGA）为载体,采用溶剂蒸发法制备蓝萼甲素胶束,并通过正交实验筛选最佳制备工艺;采用芘荧光探针法测定临界胶束浓度（CMC）,透析法测载药胶束包封率和载药量,Zetasizer nano ZS仪测定其粒径和Zeta电位,透射电镜观察形态,并对其体外释放进行研究。结果胶束的CMC为2.5×10－3 mg&#8226;mL－1;平均粒径（62.49±0.60）nm,电位为（－25.4±0.4） mV;平均包封率（84.85±2.00）%;平均载药量（5.36±1.00）%;体外缓释约12 h,符合Higuchi方程。结论用三嵌段聚合物PLGA PEG PLGA可制备蓝萼甲素纳米胶束,因其缓释和纳米粒度特性而具有良好的应用前景。     

染料木素MePEG-PLGA共聚物胶束的制备及其药动学研究

目的制备染料木素(GEN)MePEG-PLGA共聚物胶束,考察其理化性质、初步稳定性及静脉给药后大鼠体内的药动学行为。方法采用改良的自乳化溶剂挥发法制备胶束,考察其形态、包封率、载药量、粒径和Zeta电位;采用动态膜透析技术考察其释药行为,并对其释药规律进行拟合;将胶束冻干品置于4℃冰箱中保存,分别于放置1 d、10 d、1个月、3个月、6个月后取样,考察其包封率和载药量变化;对健康大鼠尾静脉注射GEN胶束,采用HPLC测定GEN在大鼠体内的血药浓度,采用DAS 2.0软件处理血药浓度数据,SPSS 17.0软件对主要药动学参数进行统计学分析。结果制备所得胶束的包封率为(84.43±2.93)%,载药量为(2.63±0.91)%,粒径为(63.75±4.12)nm;GEN胶束的释药行为最符合Weibull模型;GEN胶束冻干品6个月渗漏率为2.45%,载药量下降0.18%;大鼠尾静脉注射GEN胶束和GEN乳剂40 mg.kg 1后,主要药动学参数AUC0-t分别为(99.46±4.77)mg.L 1.h和(57.51±1.37)mg.L 1.h,t1/2分别为(7.48±1.15)h和(4.95±1.15)h,Cmax分别为(16.03±1.20)mg.L 1和(16.73±1.10)mg.L 1,CL分别为(0.36±0.02)L.h 1.kg 1和(0.67±0.02)L.h 1.kg 1。结论制备所得的GEN胶束形态规整,粒径分布狭窄,包封率较高,具有一定的缓释特征,稳定性良好,并且明显改变了GEN的药动学行为,使其消除减慢,同时提高了药物的生物利用度。     

荧光分析法测定喜树果药材中的喜树碱

研究了喜树果药材、喜树碱和10-羟基喜树碱的三维荧光图谱和薄层荧光色谱,建立了测定喜树果药材中喜树碱含量的荧光分析方法。在三维荧光图谱中,喜树碱呈现3个荧光峰,激发波长λex分别为215、255和365 nm,发射波长λem均为430 nm;10-羟基喜树碱呈现4个荧光峰,λex分别为220、265、325和375 nm,λem均为555 nm。喜树碱的荧光比10-羟基喜树碱的荧光强。三维荧光图谱对照和薄层荧光色谱分析表明,喜树果药材中的荧光成分主要是喜树碱,10-羟基喜树碱和其他共存组分对喜树碱的荧光基本无干扰。在pH 3.0～6.7条件下,喜树果提取液有稳定的强荧光。以甲醇为溶剂制备喜树果药材提取液,用水适当稀释后于365/430 nm(λex/λem)波长下测定喜树碱的含量。在0.00235～0.235μg.mL 1内,荧光强度与喜树碱浓度之间呈线性关系,回归方程为IF=9+30 844 c,相关系数r=0.999(n=9)。将本法用于喜树果样品中喜树碱含量的测定,结果为0.127%,加标回收率为102%。用薄层荧光扫描法验证了本法的可靠性。结果表明,本法可用于喜树果药材的质量检验。     

大豆磷脂脂质载体与胆酸盐表面活性剂的体外相互作用

采用旋转薄膜蒸发法结合挤压过滤工艺制备大豆磷脂脂质体,所制得脂质体的平均粒径为217nm,跨距0．838,负染色脂质体经透射电镜观察,呈明显的双层膜圆球型结构。以胆酸钠盐和脱氧胆酸钠盐研究其与脂质体之间的相互作用,将500nm波长处的可见光吸收值评价胆盐-脂质体混悬液的浊度,测定脂质体的粒径变化情况。在胆酸盐加入的初期,由于胆酸盐和脂质体形成混合胶团,致使脂质体的粒径和浊度值稍有增加,进一步加入的胆酸盐使脂质体的粒径和浊度值下降。胆盐和脂质体问的相互作用经历了数个重排现象,使脂质体的粒径发生规律性的变化,这与脂质体的体内稳定性密切相关,也可反映脂质体的载药和释药特性。     

Effect of cholesterol on membrane-damaging activity of Naja nigricollis toxin γ toward phospholipid vesicles

Membrane-damaging activity of Naja nigricollis toxin γ on phospholipid vesicles was attenuated by incorporation of cholesterol into phospholipid vesicles. Deprivation of cholesterol from erythrocyte membrane enhanced notably hemolytic activity of toxin γ, while the hemolytic activity of toxin γ on cholesterol-depleted erythrocytes decreased when cholesterol was restored to membrane. Phospholipid-binding capability and oligomeric assembly upon binding with lipid vesicles were modestly affected in the presence of cholesterol. Time-resolved fluorescence and Fourier transform infrared spectra showed that phospholipid-bound toxin γ and cholesterol/phospholipid-bound toxin γ did not adopt the same conformation. Moreover, geometrical arrangement of toxin γ in contact with phospholipid vesicles was different from that with cholesterol/phospholipid vesicles as evidenced by N-(fluorescein-5-thiocarbamoyl)-1, 2-dihexadecanoyl-phosphatidylethanolamine fluorescence enhancement and color transformation of phospholipid/polydiacetylene membrane assay. Taken together, our data show that ordered phospholipid phase arising from incorporation of cholesterol affects conformation and topographical arrangement of toxin γ on water–lipid interface, thus attenuating its membrane-damaging activity against phospholipid vesicles.     

Targeting the ABCB4 gene to control cholesterol homeostasis

INTRODUCTION: Multidrug resistance 3 (MDR3) P-glycoprotein is a lipid floppase that is encoded by the ATP-binding cassette sub-family B member 4 (ABCB4) gene and plays a crucial role in proper bile formation by transporting phosphatidylcholine across the canalicular plasma membrane of the hepatocyte into bile. The relevance of this function is underscored by the severe pathology that develops in patients with ABCB4 deficiency. This deficiency leads to the destruction of hepatocytes and cholangiocytes by bile salts, because their cytolytic action is not reduced by formation of mixed micelles with phospholipid. AREAS COVERED: Evidence that phospholipid secretion into bile is also essential for biliary cholesterol secretion as cholesterol dissolves much better in mixed micelles of bile salts and phospholipid than in pure bile salt micelles. As a consequence, net biliary cholesterol secretion depends on the amount of phospholipid secreted and hence, the expression of ABCB4 indirectly determines biliary cholesterol output. EXPERT OPINION: It can be argued that upregulation of the ABCB4 gene expression may not only be beneficial for liver pathology in patients with partial ABCB4 deficiency, but also for the prevention of gallstone formation and optimal cholesterol disposition in a much larger population.     

咪达唑仑与人血清白蛋白结合的荧光光谱研究

目的:研究咪达唑仑与人血清白蛋白(HSA)的结合作用。方法:分析咪达唑仑与HSA结合的荧光猝灭光谱和同步荧光光谱(激发波长和发射波长的间距(Δλ)分别为15nm和60nm);由Stern-Volmer方程确定咪达唑仑对HSA17℃和37℃时的荧光猝灭速率常数(Kq)及机制,Lineweaver-Burk双对数方程确定17℃和37℃时猝灭反应结合常数(KA)和结合位点数(n);根据反应前后的焓变ΔH和熵变ΔS的相对大小判断咪达唑仑与HSA之间的主要作用力类型。结果:荧光猝灭光谱显示咪达唑仑与HSA有荧光猝灭作用,Δλ=15nm波长的同步荧光光谱显示咪达唑仑对酪氨酸残基发生作用,未对色氨酸残基发生作用;在17℃和37℃时的Kq分别为5.0246×1011和4.757×1011L·mol-1·s-1;17℃和37℃时猝灭反应KA和n分别为2.1717×104、8.7438×103mol·L-1,1.1895、1.0769个;反应前后的ΔH和ΔS均<0。结论:咪达唑仑对人血清白蛋白的猝灭过程为静态猝灭,咪达唑仑与HSA间的作用力主要为范德华力或者氢键作用力。     

Effects of loading procedures of magnetic nanoparticles on the structure and physicochemical properties of cisplatin magnetic liposomes

The effects of different loading procedures of magnetic nanoparticles (MNs) on the structure and physicochemical properties of cisplatin magnetic liposomes were investigated by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy. 1, 2-Dipalmitoyl-sn-glycero-3-Phosphocholine based cisplatin magnetic liposomes were prepared using two different procedures. In procedure I, MNs were combined with phospholipids during film formation; MNs were embedded in a phospholipid bilayer. In procedure II, MNs were mixed with drugs during hydration and MNs were contained in an interior aqueous compartment. The encapsulation efficiency of cisplain and the content of MN in procedure I liposomes were 33.5%?±?3.3% and 2.34?±?0.09?mg?mL^?1, respectively. It indicated that the deliberate MN loading into the liposome structure was not only successful using procedure I, but also superior over procedure II both in cisplatin encapsulation efficiency and MN content, which can promote the magnetic targeting effect of magnetic liposomes during delivering cisplatin.     

Targeting the ABCB4 gene to control cholesterol homeostasis

Introduction: Multidrug resistance 3 (MDR3) P-glycoprotein is a lipid floppase that is encoded by the ATP-binding cassette sub-family B member 4 (ABCB4) gene and plays a crucial role in proper bile formation by transporting phosphatidylcholine across the canalicular plasma membrane of the hepatocyte into bile. The relevance of this function is underscored by the severe pathology that develops in patients with ABCB4 deficiency. This deficiency leads to the destruction of hepatocytes and cholangiocytes by bile salts, because their cytolytic action is not reduced by formation of mixed micelles with phospholipid.

Areas covered: Evidence that phospholipid secretion into bile is also essential for biliary cholesterol secretion as cholesterol dissolves much better in mixed micelles of bile salts and phospholipid than in pure bile salt micelles. As a consequence, net biliary cholesterol secretion depends on the amount of phospholipid secreted and hence, the expression of ABCB4 indirectly determines biliary cholesterol output.

Expert opinion: It can be argued that upregulation of the ABCB4 gene expression may not only be beneficial for liver pathology in patients with partial ABCB4 deficiency, but also for the prevention of gallstone formation and optimal cholesterol disposition in a much larger population.     

光谱法和分子对接法研究盐酸雷尼替丁与溶菌酶的相互作用

目的用荧光光谱法、紫外光谱法和分子对接研究生理条件下盐酸雷尼替丁与溶菌酶相互作用的光谱特性,为盐酸雷尼替丁的体内代谢过程提供一定的理论依据。方法在激发波长(λ_ex)282 nm条件下,测定盐酸雷尼替丁与溶菌酶在不同温度下的荧光猝灭光谱;使用Stern-Volmer曲线方程判断猝灭机制;计算其结合常数(K)、结合位点数(n)和结合距离(r);根据热力学参数判断作用力类型;考察二者的相互作用对溶菌酶构象的影响;应用分子对接模拟二者之间可能存在的作用形式。结果盐酸雷尼替丁可使溶菌酶内源荧光发生猝灭,猝灭机制为复合式静态猝灭;与溶菌酶在25,30和37℃下的K分别为0.82×10³,0.13×10³和0.05×10³L·mol^-1,n分别为0.72,0.56和0.46;通过计算其热力学参数焓变(△H)为-177.25 kJ·mol^-1,熵变(△S)为-540.97 J·mol^-1·K^-1,推断主要作用力类型为氢键和范德华力;供能体与受能体之间r为1.63 nm,推测之间发生了非辐射能量转移;同步荧光光谱、紫外吸收光谱和三维荧光光谱表明,结合反应对溶菌酶的构象有影响;分子对接结果表明,雷尼替丁与Ser72残基形成了2个氢键。结论盐酸雷尼替丁可与溶菌酶结合,猝灭机制为复合式静态猝灭,同时雷尼替丁对溶菌酶的构象有影响。     

维生素B2和B6的同步荧光分析法及其在维生素复合制剂中的应用

本文建立了维生素B₂和B₆的同步荧光分析法。以△λ=58nm进行同步扫描所得的两个同步荧光峰(以发射波长表示,分别位于526nm和389nm)可用以同时分别定量维生素B₂和B₆。方法快速、灵敏。维生素B₂和B₆的工作曲线线性范围分别为0～1μg/ml和0～1.5μg/ml,检出限分别为0.5ng/ml和1ng/ml。方法已应用于三种复合维生素B制剂中维生素B₂和B₆的分析。