脑靶向给药系统研究进展

血-脑屏障阻碍药物进入脑组织,不利于中枢神经系统疾病的治疗.本文介绍了近年来脑靶向给药系统的研究进展,包括通过受体(如载脂蛋白受体、转铁蛋白受体等)介导的主动靶向系统、被动靶向系统(如纳米粒、碳纳米管等)及其他靶向系统(如磁性微粒、阳离子制剂等).     

转铁蛋白修饰的喜树碱- 树枝状高分子复合物的药动学研究

目的探讨转铁蛋白修饰的主动靶向纳米载药复合物在大鼠体内的药动学行为。方法碱水解后采用HPLC法测定大鼠尾静脉给药后血浆中的药物浓度。结果经转铁蛋白修饰的主动靶向复合物能显著提高喜树碱在大鼠体内的半衰期及平均滞留时间,比未经转铁蛋白修饰的载药复合物的半衰期的平均滞留时间短。结论转铁蛋白-聚乙二醇-聚酰胺-胺树枝状分子-喜树碱复合物具有显著的长循环效果。关键词:聚酰胺-胺树枝状聚合物;转铁蛋白;聚乙二醇;喜树碱;药动学     

叶酸受体介导的肿瘤靶向纳米递药系统

叶酸受体在上皮源性的恶性肿瘤细胞膜表面高度表达。叶酸靶向纳米递药系统具有叶酸-叶酸受体主动靶向和纳米递药系统被动靶向的双重优势,可实现化疗药物对肿瘤组织的靶向递送,有效提高药物疗效,减少毒副作用。本文就近年来研究较多的叶酸-脂质体、叶酸-树枝状聚合物、叶酸-聚合物胶束、叶酸-纳米球等叶酸受体介导的肿瘤靶向递药系统进行综述。     

转铁蛋白及其受体作为药物载体的研究进展

目的介绍转铁蛋白及其受体在药学中的应用和新的研究方向。方法通过查阅近年来国内外有关转铁蛋白和转铁蛋白受体特点及其应用的文献,综述了转铁蛋白和转铁蛋白受体的特点和分类;转铁蛋白转运金属离子的能力;利用转铁蛋白受体的抗体向脑部转运药物的应用;转铁蛋白和转铁蛋白受体的抗体与药物的结合方法及应用。结果转铁蛋白具有多态性,主要被划分为血清转铁蛋白、卵(清)转铁蛋白和乳(清)转铁蛋白;转铁蛋白受体主要有转铁蛋白受体1和转铁蛋白受体2;转铁蛋白既能转运金属离子又能转运化学药物及基因药物,并在利用转铁蛋白受体的抗体向脑部转运药物方面显示出巨大的应用前景;转铁蛋白可与药物通过静电引力直接吸附,也可以与药物通过共价键结合。结论转铁蛋白及转铁蛋白受体在靶向药物转运中得到了有效的应用,并将受到更为广泛的关注。     

叶酸受体介导的靶向纳米给药系统研究进展

叶酸受体在许多恶性肿瘤细胞表面过度表达,而在正常细胞中则几乎不表达或只有少量表达。利用叶酸受体表达的特性,通过将叶酸修饰于药物载体表面,可使药物靶向输送至叶酸受体过度表达的肿瘤细胞中,从而避免对正常细胞产生毒性,提高药物疗效;而纳米给药系统因粒径较小等原因可使药物在肿瘤部位浓集。本文对近年来叶酸受体介导的靶向纳米给药系统进行了综述。     

受体介导的肝靶向载药系统研究进展

介绍近几年已报道的有关受体介导的肝靶向载药系统的研究情况。近年来受体介导的肝靶向载药系统的研究取得了一些可喜进展,相关配体-受体可与药物、脂质体、纳米粒、基因、偶联物等相连,提高药物或载体的肝靶向能力。受体介导机制在肝靶向载药系统的研究领域具有广阔的应用前景,尤其是肝脏特异性受体的不断发掘,丰富了肝主动靶向的理论体系,展示了肝脏疾病治疗的美好未来。     

抗肿瘤药物靶向载体系统的研究与开发

综述肿瘤靶向给药的基础和抗肿瘤药物靶向载体系统的发展。分类介绍普通被动靶向载药系统（如微乳、传统脂质体、聚合物纳米粒、固体脂质纳米粒、纳米脂质载体、药-脂结合物纳米粒等）、表面修饰的被动靶向载药系统及主动靶向载药系统（如免疫脂质体、免疫聚合物纳米粒及受体-配体介导靶向纳米载体）的研究与开发。在传统药物制剂的基础上，发展抗肿瘤药物的新型靶向载体系统，改善药物在体内的代谢动力学特性，增加药物定向富集到肿瘤部位甚至肿瘤细胞内，提高疗效，降低毒副作用，是近年来备受关注的课题。     

叶酸受体介导的靶向给药研究进展

目的：介绍叶酸受体介导的靶向给药研究进展。方法：根据近年来的文献资料，对叶酸受体介导的靶向给药研究进行综述。结果：叶酸受体可以与叶酸及其类似物特异性结合，从而提高药物在肿瘤、关节炎的组织分布，达到靶向诊断、治疗的目的。结论：叶酸受体介导的靶向给药是一种很有前景的给药方式。     

功能基修饰的脑靶向递药系统的研究概况

目的:研究功能基修饰的脑靶向递药系统,为提高脑靶向递药系统的靶向效率提供参考。方法:以"功能基""修饰""脑靶向""Functional group""Modified""Brain-targeting"等为关键词,组合查询2001年1月-2018年12月在中国知网、万方数据、维普网、PubMed、Elsevier、Springer Link等数据库中的相关文献,对功能基修饰的脑靶向递药系统进行综述。结果与结论:共检索到相关文献394篇,其中有效文献41篇。脑靶向包括受体介导(介导的受体如转铁蛋白受体、低密度脂蛋白受体、N-乙酰胆碱受体等)、转运体介导(介导的转运体如葡萄糖转运体、谷胱甘肽转运体等)、吸附介导。以上述受体、转运体的配体作为功能基,采用共价键结合或非共价键连接方法进行修饰,构建脑靶向递药系统;功能基通过与相应受体或转运体特异性结合,使药物跨越血脑屏障(BBB)并且在脑内病灶部位释药;除此之外,还可通过功能基带有的正电荷与BBB膜上的负电荷发生静电吸附作用产生非特异性的吸附,介导药物进入脑内。基于受体介导、转运体介导、吸附介导的靶向方式,有望提高脑组织中的药物浓度,提高中枢神经系统疾病的治疗效果,降低毒副作用及不良反应。与受体介导、转运体介导、吸附介导相比较,双级靶向可同时修饰两种靶向分子(一种靶向分子靶向于BBB,另一种靶向分子靶向于病灶),有望提高脑部疾病的治疗效果并降低药物在非病灶部位的蓄积,是一种更为理想的手段。在后续相关研究中建议开发新靶点和新型靶向分子,进一步提高脑靶向递药系统的靶向效率,为开发操作简单、成本低廉的脑靶向递药系统提供参考。     

肿瘤靶向治疗药物研究进展

近年来,随着分子生物学技术的提高及从细胞受体和增殖调控的分子水平对肿瘤发病机制的进一步认识,开始了针对细胞受体、关键基因和调控分子为靶点的治疗,即“靶向治疗”.所谓靶向药物治疗就是使药物瞄准肿瘤部位,在局部保存相对较高的浓度,延长药物作用时间,提高对肿瘤细胞的杀伤力,但对正常组织细胞作用较小.目前,用于肿瘤靶向治疗的药物有控缓释化疗药、脂质体化疗药、分子靶向药物、放射性核素等,药物可通过多途径给予,如血管介入给药、超声介导靶向经皮给药等。     

Multifunctional PLGA nanoparticles combining transferrin-targetability and pH-stimuli sensitivity enhanced doxorubicin intracellular delivery and in vitro antineoplastic activity in MDR tumor cells

Targeted delivery aims to enhance cellular uptake and improve therapeutic outcome with higher disease specificity. The expression of transferrin receptor (TfR) is upregulated on tumor cells, which make the protein Tf and its receptor vastly relevant when applied to targeting strategies. Here, we proposed Tf-decorated pH-sensitive PLGA nanoparticles containing the chemosensitizer poloxamer as a carrier for doxorubicin delivery to tumor cells (Tf-DOX-PLGA-NPs), aiming at alleviating multidrug resistance (MDR). We performed a range of in vitro studies to assess whether targeted NPs have the ability to improve DOX antitumor potential on resistant NCI/ADR-RES cells. All evaluations of the Tf-decorated NPs were performed comparatively to the nontargeted counterparts, aiming to evidence the real role of NP surface functionalization, along with the benefits of pH-sensitivity and poloxamer, in the improvement of antiproliferative activity and reversal of MDR. Tf-DOX-PLGA-NPs induced higher number of apoptotic events and ROS generation, along with cell cycle arrest. Moreover, they were efficiently internalized by NCI/ADR-RES cells, increasing DOX intracellular accumulation, which supports the greater cell killing ability of these targeted NPs with respect to MDR cells. Altogether, these findings supported the effectiveness of the Tf-surface modification of DOX-PLGA-NPs for an improved antiproliferative activity. Therefore, our pH-responsive Tf-inspired NPs are a promising smart drug delivery system to overcome MDR effect at some extent, enhancing the efficacy of DOX antitumor therapy.     

Novel Liposomal Formulation for Targeted Gene Delivery

Purpose Development of a polyethylene glycol (PEG)-stabilized immunoliposome (PSIL) formulation with high DNA content suitable for in vivo intravenous administration and targeted gene delivery. Materials and Methods Plasmid DNA was condensed using 40% ethanol and packaged into neutral PSILs targeted to the mouse transferrin receptor using monoclonal antibodies (MAbs; clones RI7 and 8D3) attached to their PEG maleimide moieties. PSILs size was measured by quasi-elastic light scattering. The targeting capacity of the formulation was determined by transfection of mouse neuroblastoma Neuro 2A (N2A) cells with PSIL-DNA complexes conjugated with either RI7 or 8D3 MAbs. Results DNA encapsulation and MAb conjugation efficiencies averaged 71 ± 14% and 69 ± 5% (mean ± SD), respectively. No alteration in mean particle size (< 100 nm) or DNA leakage were found after 48 h storage in a physiological buffer, and the in vivo terminal half-life reached 23.9 h, indicating that the PSIL-DNA formulation was stable. Addition of free RI7 MAbs prevented transfection of N2A cells with PSIL-DNA complexes conjugated with either RI7 or 8D3 MAbs, confirming that the transfection was transferrin receptor-dependent. Conclusions The present data suggest that our new PSIL formulation combines molecular features required for targeted gene therapy including high DNA encapsulation efficiencies and vector-specific transient transfection capacity. Rivest, Phivilay, contributed equally to this work.     

Synergistic targeted delivery of payload into tumor cells by dual-ligand liposomes co-modified with cholesterol anchored transferrin and TAT

This study was mainly focused on developing a dual-ligand liposomal delivery system to enhance both targeting specificity and cellular uptake. The specific ligand transferrin (TF) and the cationic cell-penetrating peptide TAT were connected with cholesterol via a polyethylene glycol (PEG) spacer to prepare the dual-ligand liposomes (TAT/TF-PEG-LP). Then the in vitro cellular uptake by three kinds of cells that possessed different expressing levels of transferrin receptor (TFR) and the in vivo delivery efficiency were evaluated. Compared to the single-ligand TAT or TF modified liposomes (TAT-PEG-LP or TF-PEG-LP), TAT/TF-PEG-LP exhibited the enhanced cellular uptake and selectivity via the synergistic effect of both ligands in vitro. The ex vivo fluorescence imaging of tumors, the qualitative observation of tumor frozen section and the quantitative determination of cellular uptake in tumor tissues altogether showed the in vivo delivery efficiency of TAT/TF-PEG-LP was higher than that of other liposomes. In conclusion, the dual-ligand liposomes co-modified with TF and TAT possessed a strong capability for synergistic targeted delivery of payload into tumor cells both in vitro and in vivo.     

Transport of Human Recombinant Brain-Derived Neurotrophic Factor (BDNF) Through the Rat Blood−Brain Barrier in Vivo Using Vector-Mediated Peptide Drug Delivery

The blood–brain barrier (BBB) transport of brain-derived neurotrophic factor (BDNF) in anesthetized rats was examined in the present studies using vector-mediated peptide drug delivery. Following tritiation, the BDNF was biotinylated via a disulfide linker and was coupled to a covalent conjugate of neutral avidin (NLA), which binds the biotinylated peptide with a high affinity, and the murine OX26 monoclonal antibody to the rat transferrin receptor. Owing to the abundance of transferrin receptors on brain capillary endothelium, the OX26 monoclonal antibody undergoes receptor-mediated transcytosis through the BBB, and the NLA–OX26 conjugate transports biotinylated peptide therapeutics through the BBB. The present studies show that while unconjugated BDNF was not transported through the BBB in vivo, the conjugation of biotinylated BDNF to the NLA–OX26 vector resulted in a marked increase in the brain delivery of BDNF, as defined by measurements of the percentage of the injected dose (ID) delivered per gram of brain. Although BDNF was not transported through the BBB in vivo, this cationic peptide was avidly bound by isolated human brain capillaries via a low-affinity, high-capacity system that was inhibited by protamine and by serum protein binding of BDNF. In conclusion, these studies show that the delivery of unconjugated BDNF to brain is nil owing to the combined effects of negligible BBB transport and rapid systemic clearance of intravenous administered BDNF. The brain delivery of BDNF may be augmented by conjugation of BDNF to BBB drug delivery vectors, such as the NLA–OX26 conjugate.     

青蒿素及其衍生物纳米制剂在抗肿瘤领域中的研究进展

摘 要青蒿素及其部分衍生物在抗肿瘤方面具有潜在的临床应用价值,但存在水溶性差、半衰期短等缺点,故促使众多学者对其药物制剂进行开发和研究。纳米药物传输系统是一种新型药物递送工具,相比传统的片剂、栓剂、注射剂等,具有稳定性好、靶向释药和联合载药等诸多优点。本文综述了青蒿素类药物的纳米传输载体,包括：纳米粒、脂质体、胶束、纳米微乳和其他纳米载体,概括了青蒿素类药物纳米制剂在肿瘤治疗方面的成果和特点,其中着重介绍青蒿素类药物与转铁蛋白的联合载药递药体系的研究进展。     

转铁蛋白在蛋白多肽药物口服给药中的应用

转铁蛋白作为一种药物载体,在蛋白多肽药物的口服给药领域有着美好前景。以转铁蛋白作为药物载体,可以使蛋白肽类药物在肠道吸收;对转铁蛋白进行适当的修饰,可以提高其递送效率。本文概述了近年来转铁蛋白在蛋白多肽药物口服给药中的作用及有关转运机制的研究进展。     

DOPA-based paclitaxel-loaded liposomes with modifications of transferrin and alendronate for bone and myeloma targeting

Treatment for multiple myeloma (MM) with a combined strategy of bone and tumor targeting remains a crucial technical challenge due to the incorporation of various functional components into one single system. Here, we developed dioleoyl phosphatidic acid (DOPA)-based paclitaxel (PTX)-loaded liposomes with modifications of alendronate and transferrin (Ald-/Tf-modified PTX-L), which were capable of bone affinity mediated by phosphate groups in DOPA and alendronate, and tumor targeting offered by transferrin. Ald-/Tf-modified PTX-L had clear and well-defined spherical shape with an intermediated size of 118.8?±?4.8?nm, a highly negative surface charge of ?46.9?±?6.8?mV and a drug entrapment efficiency (DEE) of approximately 80%. When the pH was changed from pH 7.4 to pH 6.5, the accumulative release of PTX from Ald-/Tf-modified PTX-L significantly increased from 26.7?±?3.7% to 41.7?±?4.9%. Importantly, liposomes based on DOPA displayed an obviously stronger affinity with hydroxyapatite (HAp) than 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-based liposomes. Compared to PTX-L, Ald-/Tf-modified PTX-L exhibited obvious improvement of cytotoxicity (IC_50?=_?1.25?±?0.09?μg/mL), significant enhancement on PTX intracellular accumulation (16.58?±?0.62?μg/mg) and notable promotion to apoptosis induction (45.21?±?3.10%) toward myeloma (MM1s) cells. In this study of antitumor efficacy, Ald-/Tf-modified PTX-L with bone-specific targeting showed a significant effect on extending the median survival time (48 days) and terminal survival time (>?58 days) against the MM1S-injected nude mice among all formulations. The results suggested that Ald-/Tf-modified PTX-L had potential as an efficient anticancer drug delivery system for MM therapy.     

Design,synthesis, and in vitro antitumor activity of a transferrin receptor‐targeted peptide–doxorubicin conjugate

In this study, a peptide–drug conjugate was designed and synthesized by connecting a transferrin receptor (TfR)‐targeted binding peptide analog BP9a (CAHLHNRS) with doxorubicin (DOX) through N‐succinimidyl‐3‐maleimidopropionate (SMP) as the cross‐linker. Confocal laser scanning microscopy results indicated that free DOX mainly accumulated in the nuclei of both TfR overexpressed HepG2 hepatoma cells and L‐O2 normal liver cells expressing low level of TfR; most of the BP9a‐DOX conjugate displayed cytoplasmic location, and its cellular uptake by HepG2 cells was obviously reduced by TfR blockage test. Nevertheless, the cellular uptake of this conjugate by L‐O2 cells was much less than that of free DOX. Meanwhile, the BP9a‐DOX conjugate exhibited lower in vitro antiproliferative activity against HepG2 cells than free DOX, but its cytotoxic effect on L‐O2 cells was decreased compared with that of free DOX. These results suggest that BP9a could be applied as a potential TfR‐targeted peptide vector for selective drug delivery.