T7肽修饰共载多柔比星与miRNA脂质体的制备及其对结肠癌细胞的增殖抑制作用

目的 制备T7肽修饰共载多柔比星(DOX)与MIFsiRNA脂质体(T7-LPs-DOX/RNA),研究其对人源结肠癌细胞(RKO)的靶向抑制作用.方法 薄膜分散法制备脂质体,透射电镜观察其形态.流式细胞仪检测RKO细胞对不同脂质体的摄取效率和摄取机制.细胞克隆形成实验检测不同脂质体对RKO细胞存活率的影响.构建RKO细胞肿瘤球模型,观察T7-LPs-DOX/RNA对实体肿瘤球的穿透能力.结果 RKO细胞对T7-LPs的摄取效率显著强于普通脂质体,T7-LPs-DOX/RNA对RKO细胞增殖抑制作用强于其他脂质体(P＜0.05).经过T7肽修饰后,脂质体对肿瘤球的穿透能力显著增强.结论 T7-LPs-DOX/RNA是一种有效的结肠癌靶向给药系统.     

多肽修饰脂质体靶向药物递送系统研究进展

目的介绍近年来多肽修饰脂质体靶向药物递送系统的研究进展。方法查阅和归纳总结近几年相关文献。结果阐述了精氨酸-甘氨酸-天冬氨酸（RGD）多肽、丙氨酸-脯氨酸-精氨酸-脯氨酸-甘氨酸（APRPG）多肽、细胞穿透肽（CPP）、血管活性肠肽（VIP）等修饰脂质体的研究进展。多肽修饰的包载药物的脂质体可以增加药物在体内的选择性,减少药物毒副作用,提高药物治疗指数。结论多肽分子是机体内一类重要的生物活性物质,将其作为导向物以配体-受体特异性结合的方式应用于靶向药物递送系统,具有良好的研究价值和应用前景。     

多肽修饰脂质体靶向药物递送系统研究进展

目的 介绍近年来多肽修饰脂质体靶向药物递送系统的研究进展。方法 查阅和归纳总结近几年相关文献。结果 阐述了精氨酸-甘氨酸-天冬氨酸(RGD)多肽、丙氨酸-脯氨酸-精氨酸-脯氨酸-甘氨酸(APRPG)多肽、细胞穿透肽(CPP)、血管活性肠肽(VIP)等修饰脂质体的研究进展。多肽修饰的包载药物的脂质体可以增加药物在体内的选择性,减少药物毒副作用,提高药物治疗指数。结论 多肽分子是机体内一类重要的生物活性物质,将其作为导向物以配体-受体特异性结合的方式应用于靶向药物递送系统,具有良好的研究价值和应用前景。     

主动靶向脂质体研究进展

目的 介绍主动靶向脂质体最新研究进展。方法 查阅近年来国内外相关文献,对主动靶向脂质体的表面修饰、配体选择及应用进行进行总结和归纳。结果 主动靶向脂质体的表面修饰有三种方法：作为组份直接制备;键合到脂质体表面;后插入法。主动靶向脂质体可以将药物传递到靶组织、靶向细胞或靶细胞器,提高药物的生物利用度,而不增加对正常组织或细胞的毒性,是近年研究最为广泛的主动靶向给药系统。结论 主动靶向脂质体是一种非常有前途的给药系统。     

RVG29修饰脂质体对脑胶质瘤靶向性的初步研究

目的 研究一种新型配体RVG29修饰脂质体后,对体外脑胶质瘤的靶向性.方法 采用有机相合成法制备DSPE-PEG2000-RVG29 PPP(D-RVG29)材料,按照薄膜分散法制备脂质体,通过C6细胞和Hela细胞的细胞摄取考察D-RVG29修饰脂质体后,对体外脑胶质瘤的靶向性.结果 在脂质体处方中加入DSPE-PEG2000-OME(D-OME)可使D-RVG29修饰脂质体具有更好的粒径和分布范围,C6细胞对D-RVG29修饰脂质体的摄取强于未修饰D-RVG29的脂质体,Hela细胞对两种脂质体的摄取强度无明显区别.结论 D-OME可以提高D-RVG29修饰脂质体的稳定性,D-RVG29修饰脂质体具有体外脑胶质瘤细胞的靶向性.     

受体介导脂质体的研究进展

配体修饰脂质体通过受体介导的内吞作用主动靶向药物至靶位,增加了药物靶向的特异性,减少了对非靶组织器管损伤,提高了疗效,是一种具有广阔发展前景的剂型。本文综述了近年来受体介导脂质体的研究进展。     

受体介导脂质体的研究进展

配体修饰脂质体通过受体介导的内吞作用主动靶向药物至靶位，增加了药物靶向的特异性，减少了对非靶组织器管损伤，提高了疗效，是一种具有广阔发展前景的剂型。本文综述了近年来受体介导脂质体的研究进展。     

穿膜肽TAT和脑肿瘤靶向肽T7双修饰脂质体的制备和体外靶向性评价

本文旨在制备T7肽和穿膜肽TAT双修饰的脂质体(T7 and TAT dual modified liposomes,T7-TAT-LIP)用于血脑屏障和脑肿瘤细胞双级靶向药物递送。研究以CFPE为荧光探针,T7修饰的PEG-DSPE、TAT修饰的PEG-DSPE、卵磷脂、PEG-DSPE和胆固醇为材料,采用成膜水化法制备脂质体,对T7浓度、TAT浓度、连接T7和TAT的PEG长度进行优化,表征其粒径、zeta电位、形态和稳定性。以b End.3细胞和C6细胞为模型,考察T7-TAT-LIP的细胞摄取能力,表征其穿过血脑屏障和脑肿瘤细胞靶向能力。结果表明,T7用量为脂质的6%、修饰T7所用PEG链长为2000、TAT用量为脂质的0.5%、修饰TAT所用PEG链长为1000时所得到的双修饰脂质体被C6细胞摄取能力最强。优化后T7-TAT-LIP粒径为118 nm,zeta电位为-6.32 m V,透射电镜下形态圆整。脂质体在PBS中较为稳定,37℃放置24 h,浊度和粒径无明显变化;4~8℃放置1个月,粒径和PDI无明显变化。在不同时间点,b End.3和C6细胞摄取T7-TAT-LIP的强度均高于单配体修饰脂质体,且随着孵育时间提高,摄取浓度逐渐提高。这些结果说明,双修饰脂质体具有血脑屏障和脑肿瘤细胞双级靶向能力,且效果优于单配体修饰脂质体。     

配体修饰脂质体的研究进展

目的:寻找较为稳定、有效且制备方法可靠的新的配体修饰脂质体(Ligand-modified liposomes,LML)。方法:查阅配体修饰脂质体的相关文献,综述了叶酸、甘露糖基、抗体、肽等不同配体修饰的脂质体的研究进展。结果与结论:配体修饰后的脂质体在靶向性与药效学方面有明显的提升,但也面临着巨大的挑战,如抗体和蛋白质等大分子配体会增加脂质体的免疫性,加快脂质体的循环清除等。配体修饰脂质体作为药物载体将会逐渐在疫苗接种、基因转染、靶向制剂方面发挥更加重要的作用。     

提高脂质体主动靶向性材料的研究进展

目的:为制备高效的脂质体提供参考。方法:以"材料""脂质体""Materials modified liposomes"等为关键词,组合查询2000-2016年在Pub Med、中国知网、万方、维普等数据库中的相关文献,对修饰脂质体材料的种类、特点及其在制剂中的应用研究进行综述。结果与结论:共检索到相关文献439篇,其中有效文献45篇。目前用于修饰脂质体的材料主要有糖类及其衍生物、配体类、聚合物类及肽类等。其中糖类及其衍生物、配体类和肽类修饰后的脂质体具有主动靶向性,能提高药物的生物利用度;聚合物类修饰后的脂质体可提高药物的稳定性。目前国内修饰脂质体材料还处在研发阶段,临床应用较少,存在经修饰的脂质体在体内外的靶向性是否具有可比性、各类材料是否能广泛用于不同含药脂质体的修饰、修饰后的脂质体能否实现大规模生产、修饰脂质体的设计与制备过程均较普通脂质体复杂等问题,有待今后去攻克。     

透明质酸修饰的空腔靶向纳米载体制备及其体内外性能评价

目的:制备具有pH响应性的透明质酸衍生物修饰的主动靶向载药空腔纳米球载体,并进行相关性能测定.方法:采用One-pot法制备空腔碳酸钙纳米球,并用透明质酸与壳聚糖的偶联物进行修饰,得到具有pH响应性的靶向给药载体;以阿霉素作为模型药物,对载体的粒径及Zeta电位、包封率、载药量及体外释放进行考察;以人肝癌HepG2细胞...     

Folate-modified poly(2-ethyl-2-oxazoline) as hydrophilic corona in polymeric micelles for enhanced intracellular doxorubicin delivery

The transmembrane transport of drug loaded micelles to intracellular compartment is quite crucial for efficient drug delivery. In the current study, we investigated the cellular internalization and anticancer activity of doxorubicin loaded micelles with folate modified stealthy PEOz corona. Folate-decorated micelles incorporating doxorubicin were characterized for particle size, degree of folate decoration, drug loading content and encapsulation efficiency, morphology, and surface charge. The targeting capability and cell viability were assessed using HeLa, KB, A549 and MCF-7/ADR cell lines. In vitro study clearly illustrated the folate receptor (FR) mediated targeting of FA modified micelles to FR-positive human HeLa, KB and MCF-7/ADR cells, while specific delivery to FR-negative A549 cells was not apparently increased at the same experimental conditions. Cytotoxicity assay showed 60% and 58% decrease in IC₅₀ values for HeLa and KB cells, while only a slight decrease for A549 cells, following treatment with folate modified formulations. The enhanced intracellular delivery of FA modified micelles in MCF-7/ADR cells was also observed. In vivo antitumor tests revealed DOX entrapped FA-PEOz-PCL micelles effectively inhibited the tumor growth and reduced the toxicity to mice compared with free DOX. The current study showed that the targeted nano-vector improved cytotoxicity of DOX and suggested that this novel PEOz endowed stealthy micelle system held great promise in tumor targeted therapy.     

Binding Characterization of Aptamer-Drug Layered Microformulations and In Vitro Release Assessment

Efficient delivery of adequate active ingredients to targeted malignant cells is critical, attributing to recurrent biophysical and biochemical challenges associated with conventional pharmaceutical delivery systems. These challenges include drug leakage, low targeting capability, high systemic cytotoxicity, and poor pharmacokinetics and pharmacodynamics. Targeted delivery system is a promising development to deliver sufficient amounts of drug molecules to target cells in a controlled release pattern mode. Aptameric ligands possess unique affinity targeting capabilities which can be exploited in the design of high pay-load drug formulations to navigate active molecules to the malignant sites. This study focuses on the development of a copolymeric and multifunctional drug-loaded aptamer-conjugated poly(lactide-co-glycolic acid)–polyethylenimine (PLGA-PEI) (DPAP) delivery system, via a layer-by-layer synthesis method, using a water-in-oil-in-water double emulsion approach. The binding characteristics, targeting capability, biophysical properties, encapsulation efficiency, and drug release profile of the DPAP system were investigated under varying conditions of ionic strength, polymer composition and molecular weight (MW), and degree of PEGylation of the synthetic core. Experimental results showed increased drug release rate with increasing buffer ionic strength. DPAP particulate system obtained the highest drug release of 50% at day 9 at 1 M NaCl ionic strength. DPAP formulation, using PLGA 65:35 and PEI MW of ∼800 Da, demonstrated an encapsulation efficiency of 78.93%, and a loading capacity of 0.1605 mg bovine serum albumin per mg PLGA. DPAP (PLGA 65:35, PEI MW∼25 kDa) formulation showed a high release rate with a biphasic release profile. Experimental data depicted a lower targeting power and reduced drug release rate for the PEGylated DPAP formulations. The outcomes from the present study lay the foundation to optimize the performance of DPAP system as an effective synthetic drug carrier for targeted delivery.     

冬凌草甲素靶向给药系统研究进展

目的介绍冬凌草甲素靶向制剂的研究现状。方法综述近年来国内外相关研究,介绍靶向制剂靶向原理和特性、药动药效学研究进展,并对其可行性和前景进行分析。结果冬凌草甲素靶向制剂不仅可以提高冬凌草甲素的溶解度,而且提高了靶部位药物浓度,增强抗肿瘤效果、降低不良反应。结论开发更高靶向效率、安全、经济、多类型的给药系统是未来冬凌草甲素靶向制剂的研究焦点。     

适配体C2min介导的可靶向2种前列腺癌基因的递送系统

目的 通过合成可靶向两种前列腺癌的基因载体PAMAM-PEG-C2min,以提高基因的转染效率和肿瘤靶向性。方法 将双功能聚乙二醇的一端与聚酰胺-胺（PAMAM）相连,另一端与适配体（C2min）连接,并利用¹H NMR技术对合成的PAMAM-PEG-C2min基因载体进行结构鉴定。通过两种前列腺癌PC3和LNCaP细胞的体外摄取和基因转染实验（包载siR-M基因）,考察纳米复合物的生物学特性。并利用动物活体成像技术考察合成的纳米复合物的体内分布特征。结果 核磁共振结果表明,本研究成功合成了PAMAM-PEG-C2min。PC3和LNCaP细胞对PAMAM-PEG-C2min的摄取结果体现出浓度依赖性。且与不经C2min修饰的PAMA-PEGM相比,PAMAM-PEG-C2min递药系统的基因转染效率和肿瘤细胞靶向性明显提高。体内靶向性结果表明,PAMAM-PEG-C2min可实现同时靶向2种前列腺癌组织的作用。结论 本研究合成的PAMAM-PEG-C2min递送载体具有良好的肿瘤靶向性,为前列腺癌的综合治疗和靶向治疗提供了新的技术平台。     

Dual ligands modified double targeted nano-system for liver targeted gene delivery

Abstract

Context: It is now well established that the surface of nanocarriers with specific ligands defines a new biological identity, which assist in targeting and internalization of the nanocarriers to specific cell populations, such as cancers and disease organs.

Objective: The aim of this study is to develop systemically administrable dual ligands modified nano-system which could both target cancer cells and macrophages in the liver.

Methods: Transferrin (Tf) and mannan (M) were linked onto polyethylene glycol-phosphatidylethanolamine (PEG-PE) and PE separately to get transferrin-PEG-PE (T-PEG-PE) and mannan-PE (M-PE) ligands for the surface modification of carriers. The in vivo transfection efficiency of the novel dual ligands modified (D-modified) vectors were evaluated in tumor bearing animal models.

Results: D-modified solid lipid nanoparticles/enhanced green fluorescence protein plasmid (D-SLN/pEGFP) has a particle size of 198?nm and a gene loading quantity of 89%. D-SLN/pEGFP displayed over 25% higher transfection efficiency than M-PE modified SLN/pEGFP (M-SLN/pEGFP) in HepG2 cells and T-PEG-PE modified SLN/pEGFP (T-SLN/pEGFP) in Kupffer cells (KCs) isolated from mice.

Conclusion: It could be concluded that T-PEG-PE and M-PE could function as excellent active targeting ligands to improve the cell targeting ability of the carriers and the dual ligands modified vectors could be applied as a promising active targeting gene delivery system.     

Receptor-mediated targeted drug or toxin delivery

The new approach to the treatment of cancer or to immunomodulation is drug targeting. Cellular uptake of drugs bound to a targeting carrier or to a targetable polymeric carrier is mostly restricted to receptor-mediated endocytosis. Factors that influence the efficiency of receptor-mediated uptake of targeted drug conjugate are the affinity of the targeting moieties, the affinity and nature of the target antigen, density of the target antigen, the epitope of the target antigen, the type of cell target, the rate of endocytosis, the route of internalization of the ligand-receptor complex, the ability of the drug or toxin to release from its targeted carrier, the ability of the drug or toxin to escape from a vesicular compartment into the cytosol, the affinity of the carrier to the drug and the concentration of the carrier. Targeted chemotherapy is also significantly influenced by the antigenic modulation and/or immunoselection of tumor cells. The binding of drug (toxin) to targetable polymeric carrier considerably decreases unwanted side toxicity.     

Macrophage-targeted photodynamic therapy

Photodynamic therapy (PDT) uses light activatable molecules that after illumination produce reactive oxygen species and unwanted tissue destruction. PDT has dual selectivity due to control of light delivery and to some extent selective photosensitizer (PS) accumulation in tumors or other diseased tissue, additional targeted selectivity of PS for disease is necessary. The delivery of drugs to selected lesions can be enhanced by the preparation of targeted macromolecular conjugates that employ cell type specific targeting by ligand-receptor recognition. Macrophages and monocytes express a scavenger-receptor that is a high-capacity route for delivering molecules into endocytic compartments in a cell-type specific manner. We have shown that by attaching PS to scavenger-receptor ligands it is possible to get three logs of selective cell killing in macrophages while leaving non-macrophage cells unharmed. The capability to selectively kill macrophages has applications in treating cancer and in the detection and therapy of vulnerable atherosclerotic plaque and possibly for autoimmune disease and some infections.     

Honokiol-loaded polymeric nanoparticles: an active targeting drug delivery system for the treatment of nasopharyngeal carcinoma

The purpose of this study was to develop a novel drug delivery system for a sustained and targeted delivery of honokiol (HK) to the nasopharyngeal carcinoma (NPC) HNE-1 cell lines, since the folate receptor (FR) is over-expressed on their surface. Emulsion solvent evaporation was used to develop the active targeting nanoparticles-loaded HK (ATNH) using copolymerpoly (?-caprolactone)-poly (ethyleneglycol)-poly (?-caprolactone) (PCEC), which was modified with folate (FA) by introducing Polythylenimine (PEI). ATNH characterization, including particle size distribution, morphology, drug loading, encapsulation efficiency and drug release, was performed. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were employed to evaluate the shape and construction, respectively. MTT assay, cell uptake study and apoptosis test were assayed to detect the antitumor properties and targeting uptake by HNE-1 cells in vitro. Cell-cycle redistribution, ^18?F-FDG PET/CT and immunohistochemistry were performed in vivo. The ATNH we developed were successfully synthesized and showed a suitable size distribution, high encapsulation efficiency, gradual release, and targeting uptake by the cells in vitro. Moreover, ATNH significantly inhibited tumor growth, metabolism, proliferation, micro-vessel generation, and caused cell-cycle arrest at G₁ phase. Thus, these nanoparticles we developed might represent a novel formulation for HK delivery and a promising potential therapy in the treatment of cancer.     

Intracellular delivery of redox cycler-doxorubicin to the mitochondria of cancer cell by folate receptor targeted mitocancerotropic liposomes

Cancer cells reflect higher level of ROS in comparison to the normal cell, so they become more vulnerable to further oxidative stress induced by exogenous ROS-generating agents. Through this a novel therapeutic strategy has evolved, which involves the delivery of redox cycler-doxorubicin (DOX) to the mitochondria of cancer cell where it acts as a source of exogenous ROS production. The purpose of this study is to develop a liposomal preparation which exhibits a propensity to selectively target cancer cell along with the potential of delivering drug to mitochondria of cell. We have rendered liposomes mitocancerotropic (FA-MTLs) by their surface modification with dual ligands, folic acid (FA) for cancer cell targeting and triphenylphosphonium (TPP) cations for mitochondria targeting. The cytotoxicity, ROS production and cell uptake of doxorubicin loaded liposomes were evaluated in FR (+) KB cells and found to be increased considerably with FA-MTLs in comparison to folic acid appended, mitochondria targeted and non-targeted liposomes. As confirmed by confocal microscopy, the STPP appended liposomes delivered DOX to mitochondria of cancer cell and also showed higher ROS production and cytotoxicity in comparison to folic acid appended and non-targeted liposomes. Most importantly, mitocancerotropic liposomes showed superior activity over mitochondria targeted liposomes which confirm the synergistic effect imparted by the presence of dual ligands - folic acid and TPP on the enhancement of cellular and mitochondrial delivery of doxorubicin in KB cells.