不同方法制备脂质体125I-IL-8包封率的比较

本文用四种不同的方法制备脂质体,同时包裹^125I-IL-8。对不同方法制备的脂质体包裹^125I-IL-8的包封率进行对比。结果表明：机械分散法、钙融合法、反相蒸发法制备的脂质体对^125I-IL-8的包封率依次增大。而用反相蒸发法和钙融合法联合制备的脂质体对^125I-IL-8的包封率为最大。     

EPC/CH-茶多酚柔性脂质体的制备研究

目的：应用响应面法优化茶多酚柔性脂质体的制备工艺参数,筛选出最佳处方。方法：以蛋黄卵磷脂（EPC）和胆固醇（CH）作为膜材,以胆酸钠作为柔软剂,采用逆向薄膜蒸发法制备茶多酚柔性脂质体。以脂质体的包封率为考察指标,采用三因素三水平Box-Behnken响应平面法考察脂质体膜材料中蛋黄卵磷脂（EPC）与胆固醇（CH）的质量比（A）,蛋黄卵磷脂（EPC）与茶多酚（TP）的质量比（B）,水油相的体积比（C）对影响茶多酚柔性脂质体包封率的影响,对结果进行二次多项式拟合,并根据模型优化处方,得到最优结果并进行验证。结果：确定最佳工艺条件为：卵磷脂与胆固醇比例为3.82：1,卵磷脂与茶多酚比例为2.68：1,油水相体积比为4.34：1,优化得到实际最优处方包封率为57.37%,实测值与理论值无显著性差异。结论：响应平面法用于茶多酚柔性脂质体处方的优化筛选是可行的,具有很好的预测性,此处方工艺稳定,重现性好,能制得较高包封率的茶多酚柔性脂质体。     

甘氨酸脂质体的制备及其对心肌细胞缺氧/复氧损伤的影响

目的： 将甘氨酸(Gly)包封于脂质体内，制备甘氨酸脂质体(glycine liposomes)微粒；观察甘氨酸脂质体对培养心肌细胞缺氧/复氧损伤的拮抗作用。 方法： （1）采用逆相蒸发法制备Gly脂质体微粒，观察乙醚、氯仿、乙醚＋氯仿3种不同有机溶媒对包封率的影响；透射电镜观察Gly脂质体形态、粒径。（2）建立培养乳鼠心肌细胞缺氧/复氧(H/R)损伤模型，实验结束前测定各组培养液中乳酸脱氢酶（LDH）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）含量。 结果： （1）用乙醚＋氯仿混合溶媒制备的Gly脂质体包封率最高，达到64.8％（P<0.01）；（2）Gly、Gly脂质体与空白脂质体均能抑制缺氧/复氧诱导的心肌细胞LDH、CK、CK-MB释放。其中，Gly脂质体组抑制作用最为明显（P<0.05，P<0.01）。 结论： 用乙醚＋氯仿混合溶媒制备Gly脂质体能获得较高的包封率；Gly脂质体能对培养乳鼠缺氧/复氧心肌细胞发挥保护作用，其作用机制可能与脂质体携载Gly进入细胞作用于胞内细胞器有关。     

尿素脂质体偶联抗血管内皮生长因子受体的制备及理化性质

为了提高尿素注射液治疗血管瘤的疗效,降低其副作用,我们研究制备了尿素免疫脂质体,并对其理化性质进行了研究.将血管内皮生长因子受体(VEGFR)的单克隆抗体作为偶联抗体,应用逆相蒸发法及交联法制备尿素免疫脂质体并测定包封率和偶联率,通过透射电镜观察尿素免疫脂质体的特征.结果表明:尿素免疫脂质体剂型稳定,肉眼观为乳白色混悬液,透射电镜下为大单层球形或近似球形结构,直径约150～200 nm,大部分可见到类核仁结构.其包封率约为54.4%,偶联率约为36.84%.医用尿素可以制成尿素脂质体,VEGFR单克隆抗体可作为免疫脂质体的偶联抗体,但需进一步提高包封率和偶联率.     

磷脂酰聚乙二醇单甲醚脂质体的制备及其载药性能

目的 制备新型磷脂酰聚乙二醇单甲醚脂质体,并初步考察其载药性能和对人肺腺癌A549细胞的抗肿瘤效果.方法 化学合成一系列磷脂酰聚乙二醇单甲醚,应用超声薄膜法制备脂质体和载药脂质体,测定它们的药物包封率和粒径;采用MTT法考察磷脂酰聚乙二醇单甲醚脂质体和载药磷脂酰聚乙二醇单甲醚脂质体对A549细胞增殖的影响;采用共聚焦显微镜观察脂质体在细胞中的定位.结果 载紫杉醇脂质体的药物包封率约为83％;粒径范围在100～200 nm;MTT实验显示载紫杉醇脂质体能显著抑制A549细胞的增殖并有长循环效果,而脂质体本身并无抑制作用.结论 载药磷脂酰聚乙二醇单甲醚脂质体有缓释作用,可以开发成为新型的抗肿瘤药物载体.     

包裹NR2B重组质粒免疫脂质体的制备及其特征分析

目的: 制备包裹pcDNA3.1-NR2B重组质粒的免疫脂质体.方法: 采用逆相蒸发法, 制备含pcDNA3.1-NR2B质粒的脂质体, 并与小鼠抗大鼠转铁蛋白受体的单克隆抗体(mAb OX26)相连, 形成免疫脂质体, 并对其形态结构、粒径、包封率及偶联抗体的分布进行初步检测研究.结果: 所获得的免疫脂质体近球形、平均粒径低于100 nm、包封率达30.4%、偶联抗体呈均匀分布.结论: 成功地制备了免疫脂质体, 为应用于体内试验奠定了基础.     

碘海醇脂质体的制备及其质量评价

采用逆相蒸发法制备碘海醇脂质体。对脂质体的形态、包封率、粒径分布、体外释放及体内造影情况等性质进行研究。透射电镜下观察脂质体为粒径均匀的球状或近球状小囊泡。HPLC法测定碘海醇脂质体包封率为82.35%±1.82%。碘海醇脂质体平均粒径207.7nm,分散指数0.355,Zeta电位-1.83mV。体外释放度试验表明碘海醇脂质体中药物的释放明显比碘海醇单纯药物缓慢,24h才达到98.57%。体内试验结果表明脂质体包裹的造影剂比普通造影剂CT峰值推后,信号增强,作用时间延长。碘海醇脂质体包封率较高、重现性良好。将碘海醇包裹于脂质体后减少给药剂量、延长作用时间,并可能减小对血管和中枢神经的毒性。     

壳聚糖-hVEGF165基因微粒的制备及体外转染的实验研究

采用复凝聚法制备壳聚糖-hVEGF165基因微粒，观察微粒形态，测定微粒的粒径、基因包封率和载药量，以Lipofectamine^TM2000转染试剂作为阳性对照，检测微粒对心肌细胞的转染活性及对心肌细胞存活率的影响。结果表明：微粒形态多呈球形，粒径小，基因包封率和载药量均较高，转染活性略低于脂质体，但微粒对心肌细胞的毒性明显低于脂质体。     

ENHANCED ANTITUMOR EFFECTS OF INTERLEUKIN-2 LIPOSOMES IN C57BL/6N MICE WITH B-16 MELANOMA PULMONARY METASTASES

为研究白细胞介素－２（ＩＬ－２）脂质体对小鼠Ｂ－１６黑色素瘤肺转移瘤的抑制效应和对荷瘤鼠脾淋巴细胞增殖的影响，应用改良超声－薄膜法制备ＩＬ－２脂质体；正常及免疫受抑Ｃ５７ＢＬ／６Ｎ小鼠建立Ｂ－１６黑色素瘤肺转移瘤模型，腹腔注射游离ＩＬ－２（０．２×１０４～５×１０４ｕｋｇ－１ｄ－１×１０ｄ）或脂质体包封的ＩＬ－２（０．０４×１０４～１．０×１０４ｕｋｇ－１ｄ－１×１０ｄ）。结果表明：改良超声－薄膜法制备的ＩＬ－２脂质体为直径２００～２５００ｎｍ的大单层脂质体，包封率４８．２％，具有良好的稳定性。ＩＬ－２脂质体可使荷瘤鼠肺湿重下降０．４％～１３．１％，肺转移瘤结节降低２．７％～４３．５％，脾细胞３Ｈ－ＴｄＲ掺入量增加１．０５～１．９０倍，其作用效应相当于５倍量的游离ＩＬ－２，且对免疫受抑荷瘤鼠的作用更强。提示ＩＬ－２经脂质体包封后，其抑瘤活性和促进淋巴细胞增殖的活性提高约５倍，是一种有希望应用于肿瘤生物治疗的新型制剂。     

长循环超顺磁性氧化铁脂质体纳米微粒的制备及理化性质**☆

背景：常见的超顺磁性氧化铁纳米微粒都局限应用于网状内皮系统病变的诊断。 目的：尝试制备新型MR对比剂长循环超顺磁性氧化铁纳米微粒脂质体纳米微粒,并对其理化性质进行测定。 方法：采用以下方法制备长循环超顺磁性氧化铁脂质体纳米微粒：①精密称取一定量DSPG、DSPE-PEG2000,采用薄膜分散法合成长循环空白脂质体纳米微粒。②采用化学共沉淀法,在碱性条件下与月桂酸反应形成月桂酸稳定的超顺磁性氧化铁纳米微粒。③将上述反应产物以一定比例混合,加入TES缓冲液透析3 d,过凝胶柱去除过大的脂质体及游离的磷脂。 结果与结论：长循环超顺磁性氧化铁脂质体在电镜下显示为类圆形、大小较均匀。衍射图说明产物均为面心立方尖晶石结构的Fe3O4,而且粒子的结晶状态很好。多分散系数为0.212。长循环超顺磁性氧化铁脂质体纳米微粒铁含量为6.721 3 g/L。长循环超顺磁性氧化铁脂质体T2值随着铁浓度的增加逐渐下降。提示制备的长循环超顺磁性氧化铁脂质体纳米微粒粒径大小适宜,分布均匀,可制成适合于皮下或静脉注射的制剂。     

Localized drug delivery using crosslinked gelatin gels containing liposomes: factors influencing liposome stability and drug release

We describe a drug-delivery vehicle that combines the sustained release properties of liposomes with the structural advantages of crosslinked gelatin gels that can be implanted directly or coated onto medical devices. Liposome inclusion in gelatin gels does not compromise thermal stability nor does it interfere with the resiliency of gels to tensile force. However, electron spin resonance analysis of sequestered DPPC liposomes revealed a slight depression (ca. 1.0 degrees C) of the gel-to-fluid phase transition relative to liposomes in suspension. The level of liposome release from gels was determined by liposome concentration, liposome size, and the presence of poly(ethylene oxide) chains in the gel matrix or in the liposome membrane. Both neutral and charged liposomes displayed relatively high affinities for poly(ethylene glycol)gelatin gels, with only 10-15% release of initially sequestered liposomes while liposomes in which poly(ethylene glycol) was included within the membrane were not as well retained (approximately 65% release). The in vitro efflux of ciprofloxacin from liposomal gels immersed in serum was nearly complete after 24 h compared to 38% release of liposomal chlorhexidine after 6 days. The serum-induced destabilization of liposomal ciprofloxacin depended on the accessibility of serum components to gels as partly immersed gels retained approximately 50% of their load of drug after 24 h. In vivo experiments using a catheterized rabbit model of urinary tract infection revealed the absence of viable Escherichia coli on coated catheter surfaces in seven out of nine cases while all untreated catheter surfaces examined (n = 7) were contaminated.     

Preparation of RGD-modified Long Circulating Liposome Loading Matrine,and its in vitro Anti-cancer Effects

Aim: To prepare RGD-modified long circulating liposome (LCL) loading matrine (RGD-M-LCL) to improve the tumor-targeting and efficacy of matrine. Methods: LCL which was prepared with HSPC, cholesterol, DSPE-PEG2000 and DSPE-PEG-MAL was modified with an RGD motif confirmed by high performance liquid chromatography (HPLC). The encapsulation efficiency of RGD-M-LCL was also detected by HPLC. MTT assay was used to examine the effects of RGD-M-LCL on the proliferation of Bcap-37, HT-29 and A375 cells. The percentage of apoptotic cells and morphological changes in Bcap-37 cells treated with RGD-M-LCL were detected by Annexin-V-FITC/PI affinity assay and observed under light microscope, respectively. Results: Spherical or oval single-chamber particles of uniform sizes with little agglutination or adhesion were observed under transmission electronic microscope. The RGD motif was successfully coupled to the DSPE-PEG-MAL on liposomes, as confirmed by HPLC. An encapsulation efficiency of 83.13% was obtained when the drug-lipid molar ratio was 0.1, and the encapsulation efficiency was negatively related to the drug-lipid ratio in the range of 0.1~0.4, and to the duration of storage. We found that, compared with free matrine, RGD-M-LCL had much stronger in vitro activity, leading to anti-proliferative and pro-apoptotic effects against cancer cells (P<0.01). Conclusion: RGD-M-LCL, a novel delivery system for anti-cancer drugs, was successfully prepared, and we demonstrated that the use of this material could augment the effects of matrine on cancer cells in vitro.     

脂质体姜黄素联合索拉非尼对人肝癌Huh7细胞的抑制作用

【摘 要】 目的:探讨脂质体姜黄素联合索拉非尼对肝癌Huh7细胞的抑制作用。 方法:采用脂质体包埋技术制备脂质体姜黄素,并通过Nano-ZS激光粒度测定仪测定其粒径大小及Zeta电位。分别用浓度为10 ?mol/L脂质体姜黄素、0.1 ?mol/L索拉非尼单独及联合处理人肝癌Huh7细胞,应用CCK8检测和EdU检测评价其对Huh7细胞增殖的影响,通过Transwell小室迁移实验检测其对Huh7细胞迁移能力的影响。 结果:获得粒径为（118.7±13.6） nm、Zeta电位为（-9.8±1.1） mV的脂质体姜黄素,脂质体姜黄素单独使用可显著抑制Huh7细胞的增殖和迁移,脂质体姜黄素与索拉非尼联合使用可显著提高索拉非尼对Huh7细胞增殖与迁移的抑制能力。 结论:脂质体姜黄素与索拉非尼联合使用可显著抑制肝癌Huh7细胞的增殖和迁移,是肝癌治疗的一种潜在策略。     

Preparation and Targeting Evaluation of Recombined Intrakine Plasmid pEGFP/SDF-1/KDE/Folate-Liposome Complexes

Objective:To prepare folate liposome complexes of recombinant plasmid pEGFP/SDF-1/KDEL wich contained intrakine SDF-1/KDEL gene and to observe its targeting for breast cancer cells.Methods:Reverse phase evaporation method was employed for preparing folate-liposome complexeses of pEGFP/SDF-1/KDEL,so that preparation condition was optimized;and fluorometric method was taken for testing encapsulation efficiency.Particle diameter of liposome was tested by transmission electron microscopy.Complexeses encapsulated with 0.05-0.25 mg/ml calcein were got and incubated with breast cancer cell line MDA-MB-231 cells for 2 to 12 h,then dissolved them with dimethyl sulfoxide,then detected absorbance with microplate reader.Results:The optimized encapsulation condition are as follows:molecular ratio of lecithin and cholesterol was 3:1,rotary speed was 150 r/min under temperature of 43℃,and encapsulation efficiency reached 81%in this experiment.Average liposome particle diameter was 210 nm;8 h after incubation, the intake of MDA-MB-231 cells to 0.25 mg/ml compounds achieved saturation. Conclusion:The pEGFP/SDF-1/KDEL folic acid liposome complexes prepared has a high encapsulating rate,liposome particle diameters are homogeneous,which is available for targeting for breast cancer cells in vitro.     

A simple one-step protocol for preparing small-sized doxorubicin-loaded liposomes.

A simple, single-step, extrusion-free protocol for preparing doxorubicin-loaded liposomes (100150 nm), based on the ethanol injection method (EIM), is described. Efficient encapsulation of doxorubicin (up to 98%) was obtained concomitantly with liposome preparation avoiding the need for an additional loading step. Parameters such as stock concentration of phospholipid, injection ratio, lipid composition, and drug-to-phospholipid ratio affected the resultant liposome size and magnitude of doxorubicin encapsulation. A lipid stock concentration (50 mM) and injection ratio (1:10) resulted in 96.0 +/- 2.92% encapsulation efficiency of doxorubicin (drug-to-lipid mole ratio: 0.192) and mean diameter of 135 +/- 2.32 nm for SCOL-2 formulation (DSPC/ cholesterol /oleic acid: 2/2/1; molar ratios). Replacement of phospholipid DSPC with DMPC or DPPC did not affect the mean liposome size and doxorubicin-encapsulation efficiency. These findings offer promise for scale-up and development on a large-scale production of doxorubicin-loaded liposomes for effective cancer therapy.     

Effect of liposomes on hamster oral mucosa

The histologic reaction to topically applied or intramucosally injected DPPC/chol (2:1 molar ratio) liposomes was investigated. No reaction to liposomes was observed 4 days after daily topical application. However, a mild focal immune type inflammatory reaction was observed after 21 days topical treatment. Intramucosal injection of liposome produced no irritation but a macrophage reaction limited to the injection site, which was followed by healing and complete tissue regeneration.     

重组真核表达质粒pEGFP/hVEGF165转染兔成骨细胞条件的优化

背景：血管内皮生长因子能够提高骨细胞的增殖能力,促进骨折局部血管发生,在骨缺损修复过程中发挥着至关重要的作用。 目的：优化重组真核质粒pEGFP/hVEGF165转染兔成骨细胞的条件,为构建新型组织工程骨种子细胞提供实验基础。 方法：体外分离、培养并鉴定兔成骨细胞。分别应用0.8,1.0,1.2 μg的质粒和1.5,2.0,2.5,3.0 μL脂质体两两组合,通过脂质体法将重组真核表达质粒pEGFP/hVEGF165转染入兔成骨细胞,转染48 h后倒置荧光显微镜下观察并测定转染率。 结果与结论：随着脂质体剂量的增加,成骨细胞死亡增多。转染48 h后,倒置荧光显微镜下可见细胞质内发绿色荧光的小颗粒成弥散分布,或在核周浓集成块状。其中,脂质体2.5 μL和质粒1.2 μg条件下的转染率最高,可达56%。说明质粒与脂质体之间的交互作用能够显著影响转染率,脂质体2.5 μL和质粒1.2 μg是转染兔成骨细胞的最佳条件。     

Simultaneous quantification of components of neoglycolipid-coated liposomes using high-performance liquid chromatography with evaporative light scattering detection

Liposomes composed of dipalmitoylphosphatidylcholine (DPPC), cholesterol and a neoglycolipid, mannopentaose-conjugated dipalmitoylphosphatidylethanolamine (Man5-DPPE), have been shown to have a strong adjuvant effect in inducing the antigen-specific cellular immunity. In this study, a rapid and simple analytical method using a HPLC system with an evaporative light scattering detector was developed for simultaneous quantification of the liposome components Man5-DPPE, cholesterol and DPPC. The chromatographic separation of these components was performed using a trimethylsilane column with an isocratic mobile phase of chloroform-methanol-water (1:33:6, v/v) after disrupting the liposomes with chloroform-methanol-water (10:10:3, v/v). This HPLC method provided sufficient reproducibility and linearity of calibration curves for the quantification of the liposome constituents. In addition, this method can be used for the quantification of various neoglycolipids with different carbohydrate structures.     

负载多柔比星的EGFR靶向光敏脂质体对胃癌细胞的杀伤作用研究

目的:构建靶向EGFR的光敏脂质体,提高化疗药物对胃癌细胞系的杀伤效果,并降低相关毒副反应.方法:以联乙炔基甘油磷脂酰胆碱(Diacetylenic glycerophosphatidylcholine,PC)(以下简称PC)为原料,采用薄膜分散法制备光反应性脂质体,表面修饰表皮生长因子受体(Epidermal gro...     

Protein adsorption on biomedical polymers with a phosphorylcholine moiety adsorbed with phospholipid.

The effects of phospholipid adsorption onto the polymer surface during adsorption of plasma proteins were investigated. When a polymer with the phosphorylcholine moiety, 2-methacryloyloxyethyl phosphorylcholine (MPC) co-polymer, was treated with dipalmitoylphosphatidylcholine (DPPC) liposome solution, an organized adsorption layer of DPPC was formed on the MPC co-polymer surface, which was confirmed by differential scanning calorimetric analysis and X-ray photoelectron spectroscopy. On the other hand, an organized layer of DPPC on poly(n-butyl methacrylate) and poly(2-hydroxyethyl methacrylate) could not be found. The amount of albumin adsorbed on the polymer surfaces was decreased by pretreatment of the surface with DPPC liposome solution in every polymer case. The smallest amount of adsorbed proteins was found on the MPC co-polymer. Protein adsorption on the surface of MPC co-polymers from the plasma was also small. The difference in protein adsorption on the polymers probably reflects the difference in the orientation of the phospholipid molecules which cover the polymer surface.