喷雾干燥牛血清白蛋白微球中地塞米松磷酸钠和5-氟尿嘧啶的含量测定

用等吸收双波长紫外分光光度法测定了喷雾干燥牛血清白蛋白微球中地塞米松磷酸钠和 ５氟尿嘧啶的含量。回收率及重现性均好。方法快捷、准确。     

甲氧基聚乙二醇白蛋白5-氟尿嘧啶在小鼠体内的药动学

考察了甲氧摹聚乙二醇白蛋白5-氟尿嘧啶偶联物(mPEG-BSA-1)在小鼠体内的药物动力学,以确定它是否有延长5-氟尿嘧啶(1)的半衰期、减小其峰浓度的作用.小鼠腹腔注射mPEG-BSA-1和1原药,采用HPLC法测定血药浓度,计算两组的药动学参数:Cmax为(6.606±0.87)和(57.80±8.09)μg/ml,t1/2为(332.85±47.27)和(9.88±1.39) min,AUC0→∞为(2 721±396.2)和(1 238±180.5) μg·min·ml-1.结果显示,mPEG-BSA-1能延长1的半衰期,减小其峰浓度.     

5-羟甲基糠醛与牛血清白蛋白相互作用的光谱特性研究

目的:研究在模拟人体生理条件下5-羟甲基糠醛(5-HMF)和牛血清白蛋白(BSA)结合反应的特征。方法:采用荧光光谱法和紫外光谱法。取一定浓度的BSA与不同浓度的5-HMF溶液反应(27、37℃下),测定荧光强度和吸光度,再以此通过S理te,r测n-V定ol了m其er公相式互计结算合结时合5-常HM数F和与结B合SA位作点用数距,通离过。计结算果热:2力7、学37数℃据下探5讨-H5M-HFM与FB与SAB的SA结的合相常互数作K用分机别制为;运1.4用×1F0?3rsLt.erm能ol量-1转和移7.9原×103L.mol-1,结合位点数分别为0.61和0.78;根据基本热力学参数判断二者主要通过典型的疏水作用力发生相互作用,作用距离为5.6nm。结论:5-HMF对BSA有较强的荧光猝灭作用,该过程为静态猝灭,二者在试验浓度范围内形成了复合物,从而使5-HMF可以BSA为载体进行贮存和运输。     

5-氟尿嘧啶聚乳酸微囊的制备

采用五种不同方法制备5-氟尿嘧啶聚乳酸微囊,并对其外观性质及药物含量等进行了比较。     

亚甲蓝类似物的合成及其与牛血清白蛋白相互作用的研究

目的 合成3种亚甲蓝类似物3,7-二(二正丙胺基)-吩噻嗪-5-鎓碘化物、3,7-二(二正丁胺基)-吩噻嗪-5-鎓碘化物和3,7-二(二正戊胺基)-吩噻嗪-5-鎓碘化物,并研究模拟生理条件下这3种亚甲蓝类似物与牛血清白蛋白的相互作用.方法 通过1H-NMR及MS对这3种亚甲蓝类似物进行结构表征,应用荧光光谱法研究了模拟生理条件下这3种亚甲蓝类似物与牛血清白蛋白的相互作用.结果 3种亚甲蓝类似物和BSA相互作用形成了蛋白质-药物复合物并猝灭其固有荧光,亚甲蓝类似物与BSA相互作用过程的ΔG0<0,亚甲蓝类似物与BSA荧光残基间的距离r均小于7 nm.结论 亚甲蓝类似物和BSA相互作用的猝灭机制为静态猝灭,二者之间的反应是自发进行的.非辐射能量转移理论表明BSA与亚甲蓝类似物之间存在非辐射能量转移.同步荧光光谱和三维荧光光谱的研究结果表明,亚甲蓝类似物与BSA的相互作用导致BSA构象发生变化.     

5-氟尿嘧啶聚乙二醇-聚十六烷基氰丙烯酸酯纳米粒的制备

目的:以聚乙二醇-聚十六烷基氰丙烯酸酯(PEG-PHDCA)聚合物制备5-氟尿嘧啶(5-Fu)纳米粒,并对其进行体外释药研究.方法:采用溶剂扩散法制备5-Fu PEG-PHDCA纳米粒,在单因素基础上采用正交设计法优化得到最佳处方,并对5-Fu聚合物纳米粒的粒径、Zeta电位、载药量、包封率和体外释放进行了研究.结果:制得的5-Fu聚合物纳米粒的平均粒径为132 nm,Zeta电位为-(12±2)V,载药量为12.3%,包封率为48.8%.体外释放研究发现,5-Fu PEG-PHDCA纳米粒释药近似符合Higuchi释药模型:Q=0.564 4+8.386t1/2(r=0.996 0).结论:采用溶剂扩散法制备5-Fu聚合物纳米粒方法简单,重现性好,其体外释放显示出明显缓释作用.     

白藜芦醇联合5-氟尿嘧啶抗肿瘤活性的研究

目的探讨白藜芦醇(Res)与5-氟尿嘧啶(5-Fu)联合应用的抗肿瘤活性。方法 MTT法检测Res合用5-Fu对刀豆蛋白A诱导的小鼠脾细胞增殖的影响;接种S180肉瘤的小鼠随机分为模型组、Res组(20mg/kg)、5-Fu组(20 mg/kg)、Res合用5-Fu组(Res 20 mg/kg+5-Fu 20 mg/kg),每组10只。腹腔注射给药10 d后,各组称体重,计算抑瘤率、脾指数、胸腺指数。结果 Res合用5-Fu对淋巴细胞增殖表现出较强的抑制活性(P<0.01),抑制作用随药物浓度的增加而显著提高。Res合用5-Fu组的瘤重较模型组明显降低(P<0.01),抑瘤率达到41%,明显大于单用Res或5-Fu。Res合用5-Fu可提高脾指数和胸腺指数,对5-Fu所致的免疫低下有一定保护作用。结论 Res合用5-Fu具有较好的体内外抗肿瘤活性,两者有协同作用。     

5-氟尿嘧啶脂质体凝胶剂的制备和评价

目的 研制5-氟尿嘧啶(5-Fu)脂质体凝胶剂,并进行质量评价.方法 采用逆相蒸发-冻融法制备5-Fu脂质体,再用卡波普为基质制成凝胶剂;以离心法测定脂质体的包封率;以体外经皮渗透释药法,比较5-Fu脂质体凝胶剂及5-Fu普通凝胶剂中的经皮渗透作用.结果 5-Fu脂质体平均粒径为2.16±0.30μm,平均包封率为(56.17±2.52)%;体外透皮实验中,脂质体凝胶剂24h的药物浓度为158.6 mg·mL-1,明显高于普通凝胶剂91.2mg·mL-1.结论 载药脂质体凝胶剂可显著减少药物经皮吸收,可维持较长释药时间.     

抗氧化活性藻蓝色素与牛血清白蛋白的相互作用

目的:进一步验证藻蓝色素(phycocyanobilin,PCB)的抗氧化作用,并研究藻蓝色素与牛血清白蛋白(bovine serum albu-min,BSA)之间的相互结合反应。方法:通过1,1-二苯基-2-苦基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)清除法验证PCB的抗氧化作用。用荧光光谱法、分光光度法研究了PCB与BSA的相互结合反应。结果:PCB对DPPH自由基的清除作用呈现一定的量效关系。随着PCB浓度的增加,BSA的荧光强度有规律地降低且呈良好的线性关系。结论:抗氧化活性PCB能够有效地淬灭BSA的内源荧光,该猝灭作用属于静态荧光猝灭作用,反应的结合常数K=1.22×106L.mol-1,结合位点数n=1.14,与PCB的结合基本不会引起BSA的构象变化。     

5-氟尿嘧啶温度敏感性脂质体制备方法的优化

用正交设计法L9（34，四因素三水平）筛选5－氟尿嘧啶温度敏感性脂质体的制备工艺。用100℃水浴加热导致制剂破坏的方法作为稳定性测定标准，对制备工艺进行筛选。最终选定5－氟尿嘧啶温度敏感性脂质体的制备方法为：取主药和各种辅料，用匀浆机7000r／min搅拌1h，再用超声波乳化器在超声强度（out－putl）、超声间隙（cycle）50％状态下，超声10min，同时用水浴冷却，控制脂质体溶液温度在30－40℃之间。     

甲氧基聚乙二醇吡硫醇制备条件的优化研究

目的优化甲氧基聚乙二醇吡硫醇的制备条件。方法采用N-羟基丁二酰亚胺活性酯法合成甲氧基聚乙二醇吡硫醇,并以紫外分光光度法测定的甲氧基聚乙二醇吡硫醇中吡硫醇的载药量为考察指标,通过正交试验对合成工艺进行优化。结果甲氧基聚乙二醇吡硫醇较优工艺条件为:单甲氧基聚乙二醇4000琥珀酸单酯(mPEG4K-S)与N-羟基丁二酰亚胺(NHS)物质的量比为1∶1.5,在5℃反应2.5 h后再在5℃下加入吡硫醇和4-二甲氨基吡啶(DMAP)反应20 h。结论该合成工艺操作简便,稳定可行,产物中吡硫醇的载药量高。     

Preparation,characterization, and optimization of pancreas-targeted 5-Fu loaded magnetic bovine serum albumin microspheres

The magnetic bovine serum albumin (BSA) microspheres (MS) were prepared by emulsification/solidification method. In this experiment, two kinds of magnetic MS, e.g. BSA MS and PEG-incorporated BSA microspheres (PMS) were prepared. The obtained MS were characterized by Malvern laser particle sizer and scanning electron microscopy (SEM). The obtained MS were spherical and about 1.3 μm in size. The magnetic responsivity and in vitro release behavior of these MS were studied in detail. The in vivo distribution and targeting delivery of 5-fluorouracil (5-Fu) magnetic MS after artery administration were studied in rat. The results showed that PMS could efficiently delivery 5-Fu to the targeted site compared with BSA MS without PEG MS and free drug.     

含5－FU的杂氮硅三环衍生物抗瘤活性及吞噬活性的测定

观察含５－ＦＵ的杂氮硅三环衍生物Ⅴ对小鼠肉瘤Ｓ－１８０及ＥＳＣ的抑瘤活性及其对荷瘤小鼠吞噬功能的影响。结果表明：化合物Ⅴ对小鼠Ｓ－１８０，ＥＳＣ抑瘤率分别可达６７．１％，５６．７％，并能增强荷瘤小鼠腹腔吞噬细胞的吞噬功能，其吞噬百分率与吞噬指数与对照组相比差异均有显著意义。     

含5－FU的杂氮硅三环衍生物抗瘤活性及吞噬活性的测定

观察含５－ＦＵ的杂氮硅三环衍生物Ⅴ对小鼠肉瘤Ｓ－１８０及ＥＳＣ的抑瘤活性及其对荷瘤小鼠吞噬功能的影响。结果表明：化合物Ⅴ对小鼠Ｓ－１８０，ＥＳＣ抑瘤率分别可达６７．１％，５６．７％，并能增强荷瘤小鼠腹腔吞噬细胞的吞噬功能，其吞噬百分率与吞噬指数与对照组相比差异均有显著意义。     

多层海藻酸-壳聚糖聚电解质膜微球的制备与体外释放特性研究

目的：制备牛血清白蛋白-海藻酸-壳聚糖微球（BSA-ACM）,牛血清白蛋白-海藻酸-壳聚糖-海藻酸钠微球（BSA-ACAM）,牛血清白蛋白-海藻酸-壳聚糖-海藻酸-壳聚糖-海藻酸钠微球（BSA-ACACAM）。方法：以海藻酸钠和壳聚糖溶液为囊材,对BSA进行反复包裹,采用乳化-交联法制备BSA-ACM、BSA-ACAM、BSA-ACACAM;采用扫描电镜测定微球粒径,Micro-BCA试剂盒测定载药量,考察包封率和24h体外释药特性,并进行Higuchi方程拟合。结果：BSA-ACM、BSA-ACAM、BSA-ACACAM微球球形圆整,分散性好,平均粒径分别为（3.79±1.33）、（3.52±0.96）、（3.07±1.17）μm;载药量分别为（17.97±1.33）%、（16.95±0.46）%、（16.47±1.49）%;包封率分别为（65.78±4.98）%、（63.99±4.83）%、（55.00±1.50）%。微球体外释放速率与聚电解质膜包裹层数呈负相关,均符合Higuchi方程（r分别为0.9787、0.9869、0.9808）,24h内累积释放量分别为32.15%、25.59%、16.72%,无明显突释现象。结论：多层海藻酸-壳聚糖聚电解质膜微球能减少药物的突释,具有良好的缓释效果。     

5-羟甲基糠醛与不同血清白蛋白的结合反应机制研究

利用光谱实验结合计算机模拟技术研究中药活性成分5-羟甲基糠醛 (5-HMF) 与人血清白蛋白 (HSA) 及牛血清白蛋白 (BSA) 的结合反应机制。结果表明, 5-HMF与HSA及BSA均结合生成静态复合物, 但结合强度存在一定的差异, 5-HMF与HSA及BSA分子的结合距离不同, 且r值均很小, 说明发生了能量转移现象。药物分子与血清白蛋白 (SA) 相互作用过程中, 药物分子对HSA及BSA构象均产生影响, 使结合位域的疏水性发生改变, 但对不同血清白蛋白影响程度迥异。应用荧光相图法解析出5-HMF与BSA及HSA反应构象形态的变迁均为“二态”模型。金属离子Co (Ⅱ) 介导药物与SA相互作用的程度随SA种类不同而存在差别。依据计算机模拟建立的分子对接结果显示, 5-HMF与血清白蛋白的相互作用主要为疏水作用和氢键, 分子模拟结果与光谱实验结果一致, 此为5-HMF的药理作用机制研究提供一定理论参考。     

Preparation and Characterization of 125I Labeled Bovine Serum Albumin

Bovine serum albumin is a model protein, which has been conventionally used as protein standard and in many areas of biochemistry, pharmacology and medicine. Radioiodination procedure for bovine serum albumin employing chloramine-T as an oxidant with slight modification was evaluated critically to establish the optimal conditions for the preparation of radiolabeled tracer (¹²⁵I-BSA) with required specific activity without impairing the immune reactivity and biological activity. Optimized radioiodination procedure involving 10 µg of chloramine-T along with 20 µg of sodium metabisulphite with 60 seconds incubation at 2° yielded ¹²⁵I-BSA with high integrity.     

Preparation, characterization and biodistribution of the lactone form of 10-hydroxycamptothecin (HCPT)-loaded bovine serum albumin (BSA) nanoparticles

10-Hydroxycamptothecin (HCPT) is insoluble in both water and physiological acceptable organic solvents and tends to change into its carboxylate form, which shows minimal anticancer activity and several unpredictable side effects. The goal of this study is to exploit an appropriate delivery system for HCPT to improve the stability of its lactone form. Bovine serum albumin (BSA) nanoparticles entrapping HCPT were prepared by reformative emulsion-heat stabilization technique. During this process, HCPT transformed from lactone to carboxylate and finally back to lactone form successfully. A simple reversed-phased HPLC method was developed to analyze both lactone and carboxylate forms of HCPT synchronously. Mean particle size and the ratio of lactone and carboxylate forms of HCPT were evaluated to investigate the effects of the formulations and preparation conditions. It was indicated the percentage of lactone form of HCPT in resultant BSA nanoparticles could be improved over 95% through adjusting the concentration of NaOH solution and the stirring time after high-speed emulsification. This drug delivery system was also characterized by dynamic light scattering (DLS) and light microscopy. The investigations on drug loading, in vitro release and body distribution in rats after intravenous (i.v.) administration were also carried out. It was found that the obtained nanoparticles showed spherical shape with the mean particle size of around 600 nm, and drug loading content, encapsulation efficiency and yield achieved 2.21%, 57.5% and 90.5% with the optimal preparation conditions, respectively. The in vitro release behavior exhibited a sustaining release manner and was affected by the trypsin in medium. HCPT could release more than 90% within 20 h in the medium of pH 7.4 PBS containing 750 U/ml trypsin, but only 25% within 40 h in the pure pH 7.4 PBS. The results of body distribution study in rats showed the liver targeting potential of HCPT–BSA nanoparticles that 59.6%, 52.9% and 55.3% of the examined amount of lactone HCPT accumulated in livers at 1, 4 and 24 h after injection, respectively. These results suggest that the HCPT–BSA nanoparticles seem to be a stable delivery system for poorly soluble HCPT or its derivatives.     

Enhanced liver targeting of 5-fluorouracil using galactosylated human serum albumin as a carrier molecule

The objective of this study was to develop a liver-specific antihepatocarcinoma agent. The galactosylated human serum albumin 5-fluorouracil conjugate (GHSA-5-FU) was prepared and tested for its chemical characteristic, biodistribution and primary cytotoxicity. The matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was applied to determined the molar ratio (moles of 5-FU/mole of G-HSA and moles of galactose/mole of HSA) of the conjugate. The liver targeting ability of GHSA-5-FU labeled by ¹³¹I was evaluated by measuring the total radioactivity in organs after i.v. administration in mice and rabbits, and the cytotoxicity of the conjugate was assayed by MTT method. The results showed that the molar ratio of galactose to HSA was 50, and the 5-FU to GHSA was 15. Liver uptake in rabbits and mice peaked within 5–20 min after injection. The radioactivity (counts/g tissue) of the conjugate in the liver was several times higher than those in the other organs. The conjugate showed strong cytotoxicity, but no significant cytotoxicity difference was found between GHSA-5-FU and free 5-FU.