长春新碱PEG-PE胶束的制备及其对乳腺癌细胞生长的抑制

为提高长春新碱(VCR)的抗肿瘤活性并降低其毒副作用,利用聚乙二醇衍生化磷脂酰乙醇胺(PEG-PE)聚合物胶束作为载体制备了包载VCR的PEG-PE胶束(VCR胶束),对其理化性质和体外抗肿瘤活性进行研究.采用透射电镜观察胶束的外观形态,动态光散射法测定粒径和粒度分布,HPLC法测定包封率和体外释放度,MTT法测定VCR胶束及游离VCR对MCF-7细胞的毒性.透射电镜负染照片显示,VCR胶束呈不规则的球状结构,粒度分布窄而均一,平均粒径在(11.1±0.1)nm;VCR能有效被PEG-PE胶束包载,VCR与PEG-PE的摩尔比在1∶2～1∶10的范围内包载量均大于95%;体外释放度和耐稀释试验结果表明,VCR胶束在HBS和血清(pH7.0)两种释放介质中稳定,释放符合一级动力学释药模型;体外细胞毒试验表明,VCR胶束能显著提高VCR对MCF-7细胞生长的抑制作用.制得的VCR纳米胶束具有良好的稳定性、较高包封率和显著提高VCR的抗肿瘤活性,表明PEG-PE胶束将是VCR的一个高效输送载体.     

新型γ-聚谷氨酸自组装纳米胶束的制备及用于蛋白载体的研究

对水溶性的γ-聚谷氨酸(γ-PGA)进行了接枝改性,合成了两亲性γ-聚谷氨酸(γ-PGA)接枝衍生物,采用超声探头法制备胆甾醇基γ-PGA自组装胶束,并以卵清蛋白(OVA)作为模型蛋白,研究其载药和释药性能.结果表明,制备的两亲性胆甾醇基γ-PGA自组装胶束平均粒径为299.6+ 27.3nm,粒径的多分散系数较窄(0.17),且具有较低的细胞毒性;其疏水核-亲水壳的纳米微结构对蛋白药物显示了良好载药性能,对OVA载药量可达118.8 μg/mg,包封率33.5％;体外释药结果显示,负载OVA的甾醇基γ-PGA自组装胶束能延缓蛋白的释放,释药速率与介质pH密切相关.     

我科学家抗肿瘤化疗药物纳米载体研究获重大突破

2007年7月4日,国际著名学术期刊Journal of the National Cancer Institute发表了中科院生物物理所题为“磷脂-阿霉素自组装纳米胶束促进对肿瘤的渗透性”的研究论文。这一最新发现表明：聚乙二醇衍生化磷脂与抗肿瘤化疗药物．阿霉素可自组装形成纳米尺度的新型输送载体,     

叶酸受体介导的负载紫杉醇纳米药物输送系统的制备

目的:构建靶向肿瘤组织的药物输送系统,是解决目前临床肿瘤化疗问题的有效途径之一.我们拟开展叶酸受体介导的负载紫杉醇纳米药物输送系统的制备及其表征.方法:以丁二酰化肝素为载体,通过碳二亚胺法将叶酸和丁二酰化肝素连接,制备肝素-叶酸偶联物,然后通过物理方法将紫杉醇包裹在肝素-叶酸偶联物中,在水溶性条件下体系自组装成肝素-叶酸-紫杉醇纳米粒.应用核磁共振氢谱(1H NMR),动态光散射(DLS)和扫描电子显微镜(SEM)对构建的纳米药物结构进行表征,同时观测其在水溶性条件下的自组装行为.结果:成功制备了肝素-叶酸-紫杉醇纳米药物输送系统,检测表明药物系统带有8.5％(w/w)的叶酸并负载9.6％(w/w)的药物,SEM检测表明形成了球状的纳米颗粒,DLS表明粒子的粒径在了86 nm左右.结论:我们成功制备了叶酸受体介导的负载紫杉醇的纳米药物输送系统,在进一步开展的生物活性的检测中,希望通过叶酸受体的靶向作用,引导药物定向分布在肿瘤组织,从而提高化疗药物的治疗效果同时降低其对正常细胞的毒副作用,为开发新型靶向药物输送系统提供基础.     

混合胶束作为药物载体的研究进展

许多抗肿瘤药物因为水溶解性差,在临床上的应用受到了很大影响。胶束可将药物包载到疏水核,可显著提高药物的水溶解性,是一种极具潜力的新型给药体系。然而胶束也面临着一系列问题,比如说需要提高其在体内的动力学稳定性和热力学稳定性等。与此同时,如果想要在单一的胶束体系上实现多种功能,需要对载体材料进行繁杂的修饰,也是一个难题。由不同嵌段聚合物、聚合物/表面活性剂自组装成的混合胶束或聚离子复合物胶束,相对于单一嵌段聚合物形成的胶束而言,物理稳定性和载药能力都得到了提高。同时,通过将具有不同官能团的聚合物制备成混合胶束,可以直接方便得到多功能复合的体系。本文对混合胶束载体系统的药剂学进展进行了综述。     

α-（8-喹啉氧基）单取代酞菁锌聚合物纳米胶束的制备及其特性研究

α-(8-喹啉氧基)单取代酞菁锌(α-(8-QLO)PcZn)是一种疏水性新型光敏剂,利用二嵌段MePEG-b-PCL聚合物纳米胶束作为药物载体,制备了包载α-(8-QLO)PcZn的MePEG-b-PCL聚合物纳米胶束(简称α-(8-QLO)PcZn胶束),实验研究了它的基本光物理和光生物特性.结果表明:α-(8-QLO)PeZn胶束在水溶液中的吸收和荧光光谱与自由药物α-(8-QLO)PcZn在DMF(N,N-二甲基甲酰胺)中的吸收和荧光光谱基本相似;α-(8-QLO)PcZn胶束的平均药物包载效率为(53.07 4±0.74)%,胶束平均粒径为(79.6 4±7.8)nm,;α-(8-QLO)PcZn胶束能够很好地被鼻咽癌细胞C666-1所吸收,且主要分布在细胞核的周围.MePEG-b-PCL胶束是疏水性新型光敏剂α-(8-QLO)PeZn的一种有效传输系统.     

胆甾醇基γ-聚谷氨酸负载阿霉素纳米胶束的制备与体内外释药性能评价

笔者制备了胆甾醇基γ-聚谷氨酸负载阿霉素纳米胶束(DOX/NPs),并考察了该载药纳米胶束体系的形态与粒径、载药量、包封率以及体内外释药的特性。结果表明:DOX/NPs的最佳载药量为22.4%,包封率为90.2%,平均粒径为(312.3±7.2)nm,电镜下观察呈现明显的核壳结构。体外释药结果显示,DOX/NPs能延缓阿霉素的释放,并具有p H敏感的释药特性。小鼠体内释药结果表明:阿霉素经包埋后其消除半衰期(t1/2)、药时曲线下面积(AUC)、平均滞留时间(MRT)均明显大于游离阿霉素,达到了药物缓释的目的。     

综述——纳米材料与药物输递：基于肿瘤异常结构的纳米药物设计

肿瘤组织的血液供给在时间和空间上存在的非均质性、血管的高渗性、淋巴排出功能的低效性共同形成肿瘤微环境,阻碍治疗药物有效地运输到肿瘤,从而影响其疗效．与传统药物相比,纳米药物能优先递送到肿瘤,并具有多药载药与靶向运输等功能．但肿瘤中特有生理屏障的存在阻碍了纳米药物以有效浓度均匀地运输到肿瘤组织．一些美国食品药品管理局批准的纳米药物疗效并不显著,可能与这些生理屏障的阻碍有关．本文概述了肿瘤治疗时药物需跨过的生理屏障,并总结了克服这些生理屏障的方法,探讨了纳米药物研发时针对肿瘤异常结构优化药物递送需考虑的因素．     

巨噬细胞膜伪装纳米颗粒的制备和功能表征

摘要 目的：巨噬细胞具有炎症趋化能力,近年来巨噬细胞膜伪装的纳米递送载体引起研究者的广泛关注。本文提供了一种巨噬细胞膜伪装纳米颗粒的方法,即摄取-挤出法,并对该法制得的纳米颗粒进行表征,考察纳米颗粒在不同细胞中的摄取。方法：利用溶胶-凝胶法制备装载阿霉素的介孔硅（DMSN）纳米颗粒,再利用RAW 264.7巨噬细胞吞噬DMSN,最后将巨噬细胞连续挤出制得巨噬细胞膜伪装的载有阿霉素的介孔硅（DMSN@CM）纳米颗粒。动态光散射激光粒度仪（DLS）测定DMSN@CM颗粒的粒径和表面电位,透射电子显微镜（TEM）观察纳米颗粒形态,聚丙烯酰胺凝胶电泳（SDS-PAGE）验证细胞膜的成功伪装。然后通过激光共聚焦显微镜与流式细胞术共同考察了DMSN@CM在不同细胞中的摄取情况。结果：成功制备了DMSN和DMSN@CM纳米颗粒。DMSN粒径为116.7±3.2 nm,zeta表面电势为 -29.5± 1.3 mV;MSN@CM粒径为128.0±9.3 nm,zeta表面电势为 -26.7 ±1.2 mV。TEM与SDS-PAGE共同验证了DMSN@CM表面细胞膜的成功包覆。细胞摄取试验表明巨噬细胞膜的伪装可以抑制RAW 264.7细胞对DMSN@CM的摄取;促进MDA-MB-231细胞对DMSN@CM的摄取。结论：利用摄取-挤出法成功构建了DMSN@CM纳米颗粒,该法简便高效,为纳米颗粒的细胞膜伪装提供了一种新的手段。     

铁蛋白装载“铁-阿霉素”新策略

铁蛋白具备独特的笼状结构、自组装特性、内在的肿瘤靶向性、良好的生物相容性以及易于规模化生产等优势,是一种具有良好转化前景的纳米药物载体.目前,关于铁蛋白装载抗肿瘤药物阿霉素(doxorubicin, Dox)的研究较多,装载策略包括被动装载和主动内化两类,其中,预先螯合金属离子形成"金属-阿霉素"复合物以促进其主动进入铁蛋白内腔的装载方法具有装载量高、杀伤效应强等特点,然而,此类方法仍存在铁蛋白回收率低、蛋白完整性受损等缺陷.为此,本文结合温度孵育法,利用人重组重链铁蛋白(human heavy chain ferritin, human HFn)发展了一种基于铁离子的"金属-阿霉素"装载新策略,成功构建了"铁蛋白-铁-阿霉素"(HFn(Fe-Dox), HFeD)药物递送系统,该系统具有高装载量(80～100个/HFn)、高包封率(50%～63%)和高蛋白回收率(80%～90%)的特点.同时,该策略很好地保留了铁蛋白的结构完整性、肿瘤靶向性和药物释放可控性,因而保证了HFeD对肿瘤细胞的特异靶向和杀伤.该方法的报道有望增加HFeD成药的可能性,推动铁蛋白药物载体的发展与应用.     

Multifunctionality of lipid-core micelles for drug delivery and tumour targeting

Abstract

Phospholipid micelles have proven to be the versatile pharmaceutical nanocarrier of choice for the delivery of poorly soluble chemotherapeutics for cancer therapy using various treatment modalities. Phospholipid micelles are typically expected to increase the accumulation of the loaded drugs in tumour tissues by taking advantage of the enhanced permeability and retention effect and by ligand-mediated active targeting. Furthermore, by tailoring the composition of the micelles, it is possible to enhance the intracellular delivery of the cargo. This review highlights the important advancements in our laboratory with polyethyleneglycol phosphatidylethanolamine (PEG-PE)-based micellar drug delivery systems for improvement of the therapeutic efficacy of poorly soluble anticancer drugs.     

一种溶酶体靶向的原位自组装短肽设计及抗肿瘤活性研究

肿瘤已成为威胁人类生命的一大杀手,目前主要采用手术和放、化疗等手段进行治疗,但由于放、化疗的细胞选择性差、毒副作用明显且易引起肿瘤细胞产生耐受(/药)性,不利于肿瘤的持续治疗,因此亟待研发具有定向定位优势、毒副作用低的新型靶向药物.原位自组装多肽能识别肿瘤部位的特异性高表达物质,在肿瘤部位靶向性聚集形成稳定的纳米结构,实现精准和高效治疗,有望成为一种新型的抗肿瘤药物.本研究基于多肽原位自组装的设计理念,利用溶酶体内组织蛋白酶L的催化活性,设计了靶向溶酶体且能够原位自组装的多肽分子Fmoc-FFRIKFERQ-OH,研究了该分子的自组装特性及抗肿瘤活性.结果显示,在体外酸性条件下,组织蛋白酶L能精准切割Fmoc-FFRIKFERQ-OH分子,其酶切产物FmocFFR-OH自组装形成长纳米纤维结构,对肿瘤细胞A375和SH-SY5Y均具有较好的杀伤作用.该分子通过靶向溶酶体杀伤肿瘤细胞且对正常细胞的毒性较低,有望成为一种新型的抗肿瘤药物.     

The Investigation on Polyion Complex Micelles Composed of Diammonium Glycyrrhizinate/Poly(Ethylene Glycol)–Glycidyltrimethylammonium Chloride-Grafted Polyasparthydrazide

To prepare stable polyion complex (PIC) micelles, polyasparthydrazide (PAHy) modified with glycidyltrimethylammonium groups and methoxy poly(ethylene glycol) (mPEG) (mPEG-g-PAHy-GTA) was synthesized. The cytotoxicity of the polymer was evaluated by the methyl tetrazolium assay. The polymer entrapped the diammonium glycyrrhizinate (DG) and formed polyion complexes. The effect of pH value, grafting degree of mPEG, copolymer and drug concentration on the micelle formation was investigated by means of measuring entrapment efficiency and micelle size. In vitro DG release from the PIC micelles was detected by dialysis in various media of different ionic strengths. To examine the pharmacokinetic behavior of micelles in vivo, the time course of the drug in plasma was evaluated. The cytotoxicity of the polymer was very low. The results showed that entrapment efficiency can reach about 93%, and the mean particle size was almost 50 nm. The drug release rate decreased with a decrease in ionic strength of the release medium or an increase in the PEG grafting degree. Compared with DG solution, the AUC of DG micelles had a twofold increase. The smaller clearance and longer mean residence time of the DG micelles group compared with DG solution group showed that the DG loaded in PIC micelles can reduce drug elimination and prolong the drug residence time in the blood circulation. The results indicated that PIC micelles composed of mPEG-g-PAHy-GTA would be prospective as a drug carrier to the drugs which can be ionized in solution.KEY WORDS: diammonium glycyrrhizinate, drug delivery systems, poly(ethylene glycol)–glycidyltrimethylammonium chloride-grafted polyasparthydrazide, polyion complex micelles     

以胰岛素样生长因子受体1基因为靶的反义寡核苷酸体内外抗肿瘤研究

以胰岛素样生长因子受体－1基因为靶筛选抗肿瘤药物.根据IGF1RmRNA的二级结构设计了9条反义寡核苷酸药物,以脂质体介导进行转染,MTT染色计算细胞生长抑制率,从中筛选出一条序列并对之进行优化,最后以最佳序列进行体外作用持续时间及体内细胞生长抑制率分析.结果表明该序列在体内外具有良好的抗肿瘤活性,具有剂量依赖性关系,且对荷瘤裸鼠无明显的毒性.IGF1R可作为肿瘤治疗的新靶点.     

A Novel Transdermal Delivery System for the Anti-Inflammatory Lumiracoxib: Influence of Oleic Acid on <Emphasis Type="Italic">In Vitro</Emphasis> Percutaneous Absorption and <Emphasis Type="Italic">In Vivo</Emphasis> Potential Cutaneous Irritation

Transdermal delivery of non-steroidal anti-inflammatory drugs may be an interesting strategy for delivering these drugs to the diseased site, but it would be ineffective due to low skin permeability. We investigated whether oleic acid (OA), a lipid penetration enhancer in poloxamer gels named poloxamer-based delivery systems (PBDS), can improve lumiracoxib (LM) delivery to/through the skin. The LM partition coefficient (K) studies were carried out in order to evaluate the drug lipophilicity grade (K _{octanol/buffer}), showing values >1 which demonstrated its high lipophilicity. Both in vitro percutaneous absorption and skin retention studies of LM were measured in the presence or absence of OA (in different concentrations) in PBDS using porcine ear skin. The flux of in vitro percutaneous absorption and in vitro retention of LM in viable epidermis increased in the presence of 10.0% (w/w) OA in 25.0% (w/w) poloxamer gel. In vivo cutaneous irritation potential was carried out in rabbits showing that this formulation did not provide primary or cumulative cutaneous irritability in animal model. The results showed that 25.0% poloxamer gel containing 10.0% OA is potential transdermal delivery system for LM.     

Cytochrome P450 Enzymes and Drug Metabolism—Basic Concepts and Methods of Assessment

1. The cytochrome P450 enzyme family is one of the major drug metabolizing systems in man.2. Factors such as age, gender, race, environment, and drug treatment may have considerable influence on the activity of these enzymes.3. There are now well-established in vitro techniques for assessing the role of specific cytochrome P450 enzymes in the metabolism of drugs, as well as the inhibitory or inducing effects of drugs on enzyme activity. In vitro data have been utilized to predict clinical outcomes (i.e., pharmacokinetic interactions), with close correlations between in vitro and in vivo data.4. This information can be of considerable practical assistance to clinicians, to help with rational prescribing or to prevent or minimize the potential for drug interactions.     

Liposomal Anticancer Drugs as Agents to be used in Combination with other Anticancer Agents: Studies on a Liposomal Formulation with two Encapsulated Drugs

Abstract

When considering the use of combination therapies with liposomal anticancer agents several approaches can be defined. One approach could rely on administration of one liposomal formulation with more than one entrapped cytotoxic drug. This study focuses on an assessment of a liposomal formulation containing vincristine and mitoxantrone. Distearoyl phosphatidylcholine (DSPC)/Cholesterol (Choi) (55:45 molar ratio) liposomes were loaded with vincristine using transmembrane pH gradients. These systems were subsequently incubated with mitoxantrone to effect uptake of the second drug. Retention of both drugs was determined in vitro and in vivo. In vitro drug release indicated >95% retention of mitoxantrone and approximately 75% retention of vincristine when liposomes were prepared with an initial interior pH of 2.0. In vivo results however, demonstrated that greater than 80% of the encapsulated vincristine was released within 1 hour following i.v. administration. The instability of a liposomal formulation containing two anticancer drugs following i.v. administration may be a consequence of a combination of factors including drug-loading induced collapse of the transmembrane pH gradient, loss due to osmotic effects and an associated insertion of serum proteins into the bilayer, as well as the presence of a large biological “sink” which can alter the transbilayer drug gradient in favor of drug release.     

Brimonidine Tartrate–Eudragit Long-Acting Nanoparticles: Formulation,Optimization, <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis> Evaluation

In the present study, an effort was made to design prolonged release Eudragit nanoparticles of brimonidine tartrate by double emulsion–solvent evaporation technique for the treatment of open-angle glaucoma. The effect of various formulation variables like initial drug amount, lecithin proportion, phase volume and pH, secondary emulsifier and polymer proportion were studied. Various process variables like energy and duration of emulsification, lyophilization on the characteristics of nanoparticles and in vitro drug release profile were studied. The selected formulations were subjected to in vivo intraocular pressure-lowering efficacy studies by administering aqueous dispersion of nanoparticles into the lower cul de sac of glaucomatous rabbits. The prepared Eudragit-based nanoparticles were found to have narrow particle size range and improved drug loading. The investigated process and formulation variables found to have significant effect on the particle size, drug loading and entrapment efficiency, and in vitro drug release profile of nanoparticles. The selected formulations upon in vivo ocular irritability and tolerability tests were found to be well tolerated with no signs of irritation. In vivo pharmacodynamic efficacy studies revealed that the selected nanoparticle formulations significantly improved the therapy as area under the ∆IOP vs. time curve [AUC_{(∆IOP vs.t)}] showed several fold increase in intensity and duration of intraocular pressure (IOP) decrease. All the selected nanoparticle formulations were found to prolong the drug release in vitro and prolong IOP reduction efficacy in vivo, thus rendering them as a potential carrier in developing improved drug delivery systems for the treatment of glaucoma.     

荧光素酶mRNA的构建及电穿孔介导的mRNA体内表达特性北大核心CSCD

为构建一种非复制型mRNA平台并探究电穿孔介导的mRNA对小鼠健康状况的影响及蛋白的表达情况,以荧光素酶作为靶标基因,用T7 RNA聚合酶体外转录及酶法加帽加尾的策略制备mRNA,用活体基因导入仪通过电穿孔的方式体内递送mRNA,借助小动物活体成像系统观测荧光素酶蛋白在小鼠体内的表达强度和持续时间。结果表明,使用该非复制型mRNA平台得到的mRNA成功在体内外表达,电穿孔介导的mRNA对小鼠健康体征无明显影响,所有的小鼠均成功表达了荧光素酶蛋白,蛋白表达在电穿孔后第1天达到峰值,在第4天迅速下降,但蛋白表达强度和持续时间存在较大的小鼠个体间差异。研究对非复制型mRNA的构建及其应用于疫苗或肿瘤药物研发具有重要参考价值。     

Multifunctionality of lipid-core micelles for drug delivery and tumour targeting

Phospholipid micelles have proven to be the versatile pharmaceutical nanocarrier of choice for the delivery of poorly soluble chemotherapeutics for cancer therapy using various treatment modalities. Phospholipid micelles are typically expected to increase the accumulation of the loaded drugs in tumour tissues by taking advantage of the enhanced permeability and retention effect and by ligand-mediated active targeting. Furthermore, by tailoring the composition of the micelles, it is possible to enhance the intracellular delivery of the cargo. This review highlights the important advancements in our laboratory with polyethyleneglycol phosphatidylethanolamine (PEG-PE)-based micellar drug delivery systems for improvement of the therapeutic efficacy of poorly soluble anticancer drugs.