PELGE纳米粒的制备及影响粒径大小的因素

目的通过开环共聚方法合成三嵌段共聚物(PEG—PLGA—PEG，简称PELGE)。采用超声乳化一溶剂蒸发法(O／W)制备PELGE纳米粒。方法对可能影响纳米粒粒径大小的因素，如有机相和水相的体积比、聚合物的浓度、表面活性剂的浓度等做了较详细的考察。结果其优选方案为：高分子载体材料的质量浓度为10mg／ml，有机溶剂为丙酮／二氯甲烷(体积比为2／3/a)的混合溶剂，F68溶液的质量浓度为30g／L，油相与水相体积比为1：8。结论制备的纳米粒大小均匀，呈规整球形，粒径分布范围为60～100nm。     

离子凝胶法制备壳聚糖纳米微粒

目的 :研究医用壳聚糖 (CS)纳米微粒制备的理想条件和影响因素。方法 :采用离子凝胶法 ,以不同浓度 CS溶液与三聚磷酸盐 (TPP)溶液配比反应制备 CS纳米微粒 ,观察了 CS、TPP浓度、CS∶ TPP质量比和反应体系p H值对纳米微粒制备的影响。结果 :反应条件对纳米微粒的制备有重要影响 ,在 CS与 TPP溶液浓度分别为 0 .4～ 2 .5 m g·m l- 1 与 0 .4～ 1.5 m g· ml- 1 时 ,保持质量比在 3∶ 1～ 6∶ 1之间 ,可稳定得到 CS纳米微粒 ;当 p H值为 4 .5～ 6 .0时 CS纳米微粒保持稳定 ,当 p H值 >6 .5则出现沉淀。结论 :离子凝胶法制备 CS纳米微粒简单温和 ,不需使用有机溶剂 ,在上述反应条件下制备 ,可以得到满足生物医学应用要求的 CS纳米微粒     

叶酸偶联壳聚糖纳米粒的制备

目的制备叶酸偶联的壳聚糖纳米粒。方法根据叶酸与壳聚糖的偶联比选择最佳工艺条件,通过叶酸活性酯与壳聚糖上的氨基反应,制得叶酸偶联的壳聚糖,再通过离子交联法制得叶酸偶联壳聚糖纳米粒,并测定纳米粒的粒径和表面电位。结果正交实验结果显示叶酸活性酯用量和反应温度是影响偶联比的主要因素,在叶酸活性酯与壳聚糖用量比为2∶1,反应温度50℃,反应时间2 h的条件下可得到偶联比大致为每个壳聚糖分子上偶联3个叶酸分子的叶酸偶联壳聚糖。所制得的纳米粒粒径316 nm,表面电位为(24.85±1.14)mV,透射电镜下观察其形态圆整。结论该方法可成功制备叶酸偶联壳聚糖纳米粒。     

磁性阿霉素聚氰基丙烯酸正丁酯纳米粒的合成及其对MG-63人骨肉瘤细胞的效应

目的:利用FeCl2.4H2O、FeCl3.6H2O、α-氰基丙烯酸正丁酯、盐酸阿霉素等试剂合成磁性阿霉素聚氰基丙烯酸正丁酯纳米粒的稳定胶体液,并研究其对MG-63型人骨肉瘤细胞的作用。方法:①用FeCl2.4H2O、FeCl3.6H2O、盐酸阿霉素、α-氰基丙烯酸正丁酯等试剂合成磁性阿霉素聚氰基丙烯酸正丁酯纳米粒。②在透射电镜下观察纳米粒的物理形态;用振动样品磁强计检测纳米粒的饱和磁化强度;用紫外分光光度计测定药物的包封率、载药量。③用扫描电镜观察、MTT法和流式细胞仪测定法检测其对MG-63型人骨肉瘤细胞的作用。结果:利用FeCl2.4H2O、FeCl3.6H2O、盐酸阿霉素、α-氰基丙烯酸正丁酯等试剂成功合成了一种稳定的棕色胶体溶液;透射电镜下观察,形态近似于球形,分散度好,平均直径184.60 nm;振动样品磁强计检测胶体中纳米粒的饱和磁化强度为0.558 emu/g,紫外分光光度计等仪器测定药物的包封率为90.73%,载药量为10.68%;通过扫描电镜、MTT法和流式细胞仪测定法检测,表明该胶体溶液较ADM对MG-63人骨肉瘤细胞有更强的抑制作用。结论:该胶体溶液性质稳定,药物颗粒不超过300 nm,理论上可以在动物血管中随循环流动而不会沉淀;该纳米粒的饱和磁化强度为0.558 emu/g,微粒可被4 250 Gs的磁场所吸引,以达到磁靶向的效应;药物的包封率为90.73%,载药量为10.68%,表明药物合成的效率较好;且该胶体溶液较ADM对MG-63人骨肉瘤细胞有更强的抑制作用,为下一步动物实验提供了基础。     

Solid State NMR Investigations on Nanosized Carrier Systems

Pharmaceutical Research -     

Chemotherapeutic efficacy of poly (DL-lactide-co-glycolide) nanoparticle encapsulated antitubercular drugs at sub-therapeutic dose against experimental tuberculosis

The present study was designed to evaluate the chemotherapeutic efficacy of poly (DL-lactide-co-glycolide) (PLG) nanoparticles (NP) encapsulating three front-line antitubercular drugs (ATDs: rifampicin, RIF; isoniazid, INH and pyrazinamide, PZA) at 2/3rd therapeutic dose. PLG nanoparticles prepared by the double emulsion and solvent evaporation technique were administered orally at 2/3rd therapeutic dose to guinea pigs. A single oral administration of the formulation resulted in sustained drug levels in the plasma for 7-12 days and in the organs for 11-14 days with a significant improvement in mean residence time as well as drug bioavailability. The administration of PLG nanoparticles every 10 days (five doses) to Mycobacterium tuberculosis H(37)Rv infected guinea pigs led to undetectable bacilli in the organs, as did 46 conventional doses. Therefore, nanoparticle based antitubercular chemotherapy forms a sound basis for a reduction in dosing frequency and also offers the possibility of reducing the drug dosage.     

VEGF纳米粒的制备及药剂学性质研究

目的:将VEGF制备为纳米粒,以提高VEGF在体内的稳定性,解决VEGF半衰期短等问题,并对所制备的VEGF纳米粒进行药`剂学性质研究。方法:以无毒、可生物降解的聚氰基丙烯酸酯为材料,采用乳化聚合法制备VEGF纳米粒,对其外观形态、粒径分布、包封率和载药量以及体外释放进行考察。结果:制备了纳米粒胶体溶液及其冻干品:电子透射显微镜下观察纳米粒形态,外形为粒径比较均匀的球状或近球状的纳米粒,平均粒径为90 nm,粒径范围为50~150 nm;包封率大于85%,载药量约为42%,冻干品的再分散性良好。结论:本研究制备的VEGF纳米粒,包封率和载药量相对较高,质量稳定,重现性好。     

盐酸克班宁氰基丙烯酸正丁酯毫微粒的制备工艺研究

目的:优选盐酸克班宁毫微粒的制备最佳工艺。方法:以氰基丙烯酸正丁酯为聚合材料,采用乳化聚合法制备盐酸克班宁毫微粒Cre-PBCA-NP;以包封率为评价指标,通过均匀设计法,优化制备工艺。结果:按优化工艺条件,制得载药毫微粒,包封率80%.结论:经过优化筛选出的工艺,为盐酸克班宁聚氰基丙烯酸正丁酯毫微粒的最佳制备工艺。     

Polymersome carriers: From self-assembly to siRNA and protein therapeutics

Polymersomes are polymer-based vesicular shells that form upon hydration of amphiphilic block copolymers. These high molecular weight amphiphiles impart physicochemical properties that allow polymersomes to stably encapsulate or integrate a broad range of active molecules. This robustness together with recently described mechanisms for controlled breakdown of degradable polymersomes as well as escape from endolysosomes suggests that polymersomes might be usefully viewed as having structure/property/function relationships somewhere between lipid vesicles and viral capsids. Here we summarize the assembly and development of controlled release polymersomes to encapsulate therapeutics ranging from small molecule anti-cancer drugs to siRNA and therapeutic proteins.     

Effect of Polymer Molecular Weight on Nanocomminution of Poorly Soluble Drug

The reduction of particle size to nanometers has been an important tool used for efficient drug delivery. Solid drug nanoparticles can be conveniently prepared by nanocomminution. This process relies on mechanical energy and the selection of a proper polymeric stabilizer. The long chains of polymers provide steric stabilization for drug nanoparticles. In this research, itraconazole and hydroxypropyl cellulose were used to study the effect of the molecular weight of a polymer on particle size reduction. In principle, an increase in molecular weight produces two counteracting effects: a decrease in the diffusion rate of chains and an increase in the physical adsorption of a polymer. The effects of particle size reduction are more pronounced in systems involving smaller molecular weights, and the effects of changing molecular weights disappear with time. Systems of higher molecular weight show larger aggregates in their redispersion after drying. Based on the results of our research, it appears that polymers of smaller molecular weight are more suitable than larger polymers for efficient nanocomminution. This indicates that the kinetic aspects of molecular weight are important.