聚(2-乙基丙烯酸)脂质体的制体及其热敏性研究

采用插入法以脂肪酰胺修饰的聚(2-乙基丙烯酸)衍生物构建热敏递药的高分子脂质体。用荧光分析法，借助荧光分光光度仪和粒径仪系统地研究了高分子脂质体的热敏特性。结果发现，采用脂肪胺修饰的聚(2-乙基丙烯酸)制备的脂质体具有明显的热敏释药特性，其释药特性与插入的高分子结构有关，还与制备脂质体的磷脂组成有关，同时采用聚(2-乙基丙烯酸)制备的脂质体还具有显著的酸敏释药特性。以聚(2-乙基丙烯酸)为热敏诱导介质制备的脂质体在体外实验中呈现出良好的热敏释药特性，且制剂制备方法简便、可靠。     

聚(2-乙基丙烯酸)脂肪酰胺衍生物构建的酸敏脂质体

本实验合成了系列聚(2-乙基丙烯酸)长链脂肪酰胺衍生物，并采用高分子插入法制备了聚(2-乙基丙烯酸)酸敏高分子脂质体。应用荧光指示剂、粒径仪、荧光显微镜及细胞实验，系统研究了高分子修饰和脂肪胺的链长对高分子衍生物嵌入脂质体的效率和质量的影响。结果表明，高分子插入法可以制备聚(2-乙基丙烯酸)酸敏高分子脂质体。(1) 高分子嵌入量与高分子脂肪胺的链长无关，但与高分子修饰度相关。(2) 高分子嵌入量与起始的高分子-脂质体比例成正比。(3) 在酸性条件下聚(2-乙基丙烯酸)脂质体可产生显著的脂质体融合及释药行为。(4) 聚(2-乙基丙烯酸)脂质体在细胞内呈现出良好的酸敏诱导释药特性。实验证明这种方法制备的脂质体具有良好的酸敏释药性能，并且制备方法简便，可控性好，实用性强。     

聚(2-乙基-2-噁唑啉)修饰超氧化物歧化酶模拟物脂质体冻干制剂的制备

目的:制备聚(2-乙基-2-噁唑啉)(PEOZ)修饰超氧化物歧化酶(SOD)模拟物脂质体的冻干制剂。方法:通过考察预冻方式、预冻时间、真空干燥时间及联合冻干保护剂的种类及比例等优化冻干工艺,并测定所制制剂的水化复溶时间、粒径和包封率。结果:以10%乳糖+1%甘露醇+10%海藻糖作为联合冻干保护剂,并以外加方式加入PEOZ修饰SOD模拟物脂质体中,快速冷冻5h,真空干燥30h,可得到外观光洁、平整的目标冻干制剂;其水化复溶时间为(10±1)s,粒径为(159.3±10.2)nm,包封率为86.25%(RSD=3.26%,n=6)。结论:该优化冻干工艺质量可控,重复性好。     

酸敏高分子诱导的脂质体膜融合性能研究

本文研究了具有酸敏特性的高分子聚(2-乙基丙烯酸)诱导的脂质体-脂质体及脂质体-细胞膜之间的融合特性。采用脂肪胺修饰的聚(2-乙基丙烯酸)制备酸敏高分子脂质体。用荧光共振能量转移法定量测定脂质体间的融合程度，采用粒径仪研究脂质体在发生膜融合时的粒径变化。结果显示，聚(2-乙基丙烯酸)酸敏高分子脂质体有很强的酸敏融合性能。在酸性条件下高分子酸敏脂质体之间可以相互融合，其程度与脂质体表面酸敏高分子聚(2-乙基丙烯酸)的分子质量成正比；高分子酸敏脂质体的酸敏融合性与构成其磷脂膜的磷脂种类有关，另外脂质体膜中加入胆固醇可降低高分子酸敏脂质体的膜融合性能；高分子酸敏脂质体与血红细胞膜影融合；酸敏高分子诱导的脂质体融合会引起脂质体膜通透性的增加。聚(2-乙基丙烯酸)诱导的酸敏高分子脂质体的膜融合特性说明其可用于制备酸敏控释脂质体。     

2-(2-芳基)乙基苯甲酸的合成

以邻氰基氯苄为原料,与苯甲醛或2-噻吩甲醛经Wittig-Horner反应、水解及氢化反应制得2-(2-苯乙基)苯甲酸或2-(2-噻吩基)乙基苯甲酸,总收率分别约64%和60%。     

多西他赛pH敏感型聚(2-乙基-2-噁唑啉)-聚(D,L-丙交酯)自组装胶束的制备及其性质

目的利用两亲性嵌段共聚物聚(2-乙基-2-噁唑啉)-聚(D,L-丙交酯)[poly(2-ethyl-2-oxazo-line)-poly(D,L-lactide),PEOz-PDLLA]的自组装性能制备pH敏感型多西他赛胶束,并对其相关性质进行考察。方法运用阳离子开环聚合反应得到PEOz-PDLLA,通过FITR、1H-NMR和凝胶色谱法对其结构进行表征,采用电位滴定法测定共聚物pKa,应用荧光探针技术确定临界胶束浓度(criticalm icelle concentration,CMC)。动态光散射法和Zeta电位测试仪测定胶束的粒径和Zeta电位。以薄膜分散法包载多西他赛,并用透析法研究载药胶束的体外释放度。结果PEOz-PDLLA的亲水/疏水段分子质量比值为0.76,pKa为6.41,CMC为0.8×10-3g.L-1。载药胶束包封率为94.9%、载药量质量分数为8.7%、平均粒径为(35.3±4.9)nm、Zeta电位为(25.51±2.14)mV,在pH5.0的释放介质中释药速度加快。结论PEOz-PDLLA嵌段共聚物可自组装形成胶束,高效包载多西他赛,体外释放具有pH敏感性。     

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。     

7-乙基-10-羟基喜树碱长循环脂质体的制备及药动学研究

目的:研究7-乙基-10-羟基喜树碱长循环脂质体(Lip-SN38)的制备方法以及在大鼠体内的药动学.方法:采用两步合成法制备脂质体空间稳定膜材甲氧基聚乙二醇.磷脂酰乙醇胺(mPEG-PE);同时采用薄膜分散法制备Lip-SN38;用阳离子交换树脂微型小柱层析法分离游离药物和脂质体,紫外分光光度法测定包封率;HPLC法测定大鼠血浆中药物浓度.结果:Lip-SN38平均粒径<200 nm,药物包封率>90%;48 h只有<30%的药物体外释放;大鼠尾静脉注射Lip-SN38,剂量为10 mg·kg-1,与SN3.8溶液剂相比,t1/2β增加4.61倍.结论:采用薄膜分散法可制得包封率高、粒径小的脂质体,mPEG-PE修饰磷脂膜可增加Lip-SN38的t1/2β,延长药物在血中的循环时间.     

应用胚胎干细胞试验(EST)评价邻苯二甲酸二(2-乙基)己酯(DEHP)的胚胎毒性

目的利用小鼠胚胎干细胞试验(EST)模型,初步评价邻苯二甲酸二(2-乙基)己酯(DEHP)的胚胎毒性。方法采用悬滴悬浮法培养小鼠胚胎干细胞(m ESCs),观察受试物对m ESCs分化能力的影响,结合CCK-8法判断受试物对m ESCs及小鼠胚胎成纤维细胞(3T3)的细胞毒性结果,预测受试物的胚胎毒性。用已知强胚胎毒性化合物5-氟尿嘧啶(5-Fluorouracil,5-FU)、无胚胎毒性化合物青霉素-G(P-G)对模型进行有效性验证,并将经过验证的EST模型用于评价受试物DEHP的胚胎毒性。结果利用建立的EST模型对5-FU、P-G胚胎毒性进行评价,结果表明5-FU为强胚胎毒性,P-G为无胚胎毒性,与文献报道一致;DEHP对m ESCs和3T3的半数抑制浓度分别为IC50m ESCs=315μmol/L(126μg/ml),IC503T3=307μmol/L(122.8μg/ml),m ESCs的半数抑制分化浓度为ID50m ESCs=323μmol/L(129.2μg/ml),经EST模型判断公式计算得出该化合物为弱胚胎毒性化合物。结论建立的EST模型的有效性验证结果与ECVAM的结论一致,可用于胚胎毒性的筛选和评价;经EST模型评价DEHP的胚胎毒性为弱胚胎毒性。     

2-(氨基)乙基甲基砜盐酸盐的合成

甲基亚磺酸锌二水合物(2)与环氧乙烷经开环、氯代、取代及水解反应制得2-(氨基)乙基甲基砜盐酸盐(1),总收率50%。2或甲基亚磺酸钠与N-(2-溴乙基)邻苯二甲酰亚胺经取代和水解反应也可制得1,总收率68%或79%。     

Preparation and properties of poly(vinyl alcohol)-stabilized liposomes

The purpose of this work is to evaluate the improvement in physical stability of poly(vinyl alcohol) (PVA) modified liposomes. Liposomes composed of soya phosphatidylcholile (SPC) and cholesterol (1:1 molar ratio) were prepared by reverse phase evaporation method. Two types of interaction between liposome and PVA were investigated: PVA addition into lipid bilayer during liposome preparation and coating of already formed liposomes with PVA. The microparticles system was morphologically characterized by transmission electron microscopy (TEM) and particles analysis. Changes in particles size and zeta potential confirmed the existence of a thick polymer layer on the surface of liposomes. The amount of PVA adsorbing to liposomes and the encapsulation efficiency increased with increasing polymer concentration. The physical stability was evaluated by measuring the release rate of contents at 20 and 37 degrees C, the PVA modified liposomes were more stable than the conventional liposomes. Comparing with PVA-coated liposomes, the liposomes with PVA addition to the bilayer were more stable, and had higher entrapment efficiency.     

聚乙二醇POPA磷脂衍生物构建的酶敏脂质体

以磷酰胺键将聚乙二醇高分子MePEG2000-NH₂与磷脂POPA连接在一起, 合成聚乙二醇磷脂衍生物, 以聚乙二醇磷脂衍生物为主要膜材构建酸敏脂质体。采用荧光分析法系统研究了聚乙二醇磷脂衍生物脂质体在酸性条件下对荧光染料的释药特性。以聚乙二醇磷脂衍生物构建的酸敏脂质体,在pH 6.5～7.5时稳定,其稳定性与制备脂质体的磷脂种类及胆固醇含量密切相关,在pH 5.0时发生显著的荧光泄漏,泄漏率与环境酸性的强度及处于酸性的时间呈正相关。聚乙二醇磷脂衍生物构建的脂质体具有开发成酸敏释药脂质体的前景。
     

2-脱氧葡萄糖聚乳酸微球的制备及其体外释药性能的研究

目的采用W/O/O乳化溶剂挥发法制备2-脱氧葡萄糖聚乳酸微球(2-Deoxyglucoseloadedpoly(DL-lactide)microspheres,2DG-PLA-MS),并研究其体外释药性能。方法考察3个因素(即投药比、水丙酮体积比和丙酮液体石蜡体积比)对微球的粒径、载药量和包封率的影响,应用正交实验优选最佳制备工艺条件。结果2DG-PLA-MS的制备工艺稳定,重复性好,微球表面圆整,粒径分布均匀,微球平均粒径45μm,平均载药量为42.41%,平均包封率为72.63%。该微球在14d的药物累积释放率达82.96%。结论2DG-PLA-MS具有明显的缓慢释放作用,能够实现延长药物作用时间、减少给药次数、降低药用剂量和减少不良反应等作用。     

Preparation, characterization and controlled release investigation of interpenetrating polymer networks of poly(acrylic acid)/triazole modified poly(vinyl alcohol)

A series of interpenetrating polymer networks of poly(acrylic acid) (PAA)/triazole modified poly(vinyl alcohol) (TMIPNs) were synthesized by radical polymerization in methanol at room temperature with l-ascorbic acid (Vc) and peroxide hydrogen (H2O2) as initiators and trihydroxymethyl propane glycidol ether (6360) as a crosslinker. The structures of the gels were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The swelling/deswelling behavior of hydrogels was studied in different pH and different concentrations of NaCl aqueous solutions. The results showed that the TMIPNs hydrogels had excellent pH- and salt-sensitivity in the range of the investigation. The mechanism of the swelling and the deswelling was discussed and the results were confirmed further by scanning electron microscope (SEM). In addition, the controlled release behavior of TMIPNs in vitro was also studied. The effects of physical stimulus (ultraviolet ray and ultrasonic wave), salt concentration, pH value and the swelling/deswelling on the controlled released behavior were also explored.     

Preparation and characterization of novel poly(ethylene glycol) paclitaxel derivatives

Paclitaxel has been found to be very effective against several human cancers; one of the major problems with its use is its poor solubility, which makes necessary its solubilization with excipients that can determine allergic reactions often severe. The aim of this study is to develop highly water-soluble prodrugs of paclitaxel. For this purpose we prepared a series of new paclitaxel–poly(ethylene glycol) (PEG) conjugates that were characterized and evaluated for their in vitro stability and cytotoxicity. In particular, in order to modulate the release of paclitaxel from prodrugs, we prepared different compounds introducing PEG in the drug C2′ and/or C7 positions via ester or carbamate linkage. The conjugates were obtained in high purity and good yield. The carbamate prodrugs were highly stable in different media, while the compounds obtained linking PEG at C2′ position through an ester bond showed lower stability. Finally, the cytotoxic activity of the conjugates was evaluated on two cancer cell lines and the results showed that all the derivatives had a reduced cytotoxicity compared to that of paclitaxel.     

紫杉醇PLGA微球制备及体外性质评估

目的：以乳酸-羟基乙酸共聚物（PLGA）为材料,制备用于肿瘤内注射的紫杉醇PLGA长效缓释微球.方法：采用改良溶剂蒸发法制备,对微球的体外性质以及不同剂量（10,15,25 kGy）60Coγ射线对微球性质的影响进行考察.结果：制得的微球形态圆整,载药量、包封率、平均粒径和跨距分别为1.53%,97.29%,42.72μm和0.95.药物体外释放30 d累计释放达到56.19%,体外降解30 d后微球失去完整结构,表面粗糙.3个剂量60Coγ射线的灭菌效果均良好,且对微球的体外性质均无明显影响.微球中二氯甲烷的残留量低于药典规定的限度.结论：紫舷杉醇PLGA微球满足缓释长效的要求,对恶性肿瘤的间质化疗具有一定前景.