Summary

可逆二硫键交联胶束生产的简便和有效途径

Published: December 23, 2016
doi:

Summary

To deliver cancer drugs to tumor sites with high specificity and reduced side effects, new methods based on nanoparticles are required. Here, we describe disulfide cross-linked micelles that can be easily prepared by hydrogen peroxide-mediated oxidation and are able to dissociate efficiently under a reducing tumor environment to release payloads.

Abstract

纳米是治疗,运用是在尺度纳米生物医学应用的颗粒的独特性能的一种新兴的形式。提高药物输送到最大限度的治疗效果,减少药物的副作用是一些当今纳米的基石。特别是纳米颗粒已经发现在癌症治疗中具有广泛的应用。纳米颗粒提供了高度的设计,应用,以及基于所述肿瘤微环境的生产灵活性预计为与快速翻译到临床实践更有效。聚合物胶束纳米载体药物输送应用的热门选择。

在本文中,我们描述了用于合成根据一个明确定义的两亲性线性树枝状共聚物(telodendrimer,TD)的自组装载药,二硫化交联的胶束一个简单而有效的协议。 TD是由聚乙烯GL的ycol(PEG)作为亲水性链段和硫醇化胆酸群集作为使用基于溶液的肽化学芯成形疏水部分附着逐步到胺封端的聚乙二醇。化疗药物,如紫杉醇(PTX),可以使用标准溶剂蒸发方法被加载。将O 2介导的氧化先前用于形成从上阵的游离巯基帧内胶束二硫化物交联。然而,反应缓慢,对于大规模生产是不可行的。最近,H 2 O 2介导的氧化方法进行了探讨作为一种更可行和有效的方法,它比以前报道的方法快96倍。使用这种方法,将50克的PTX加载,二硫化物交联的纳米颗粒已成功地生产具有窄粒度分布和高载药量的效率。将所得的胶束溶液的稳定性使用扰乱条件如共孵育瓦特分析了第i洗涤剂,十二烷基硫酸钠,有或没有还原剂。相比,他们的非交联的对应时,载药,二硫化交联的胶束显示出较少的溶血活性。

Introduction

纳米技术是受益了许多医学领域1的快速新兴领域。纳米颗粒提供用于设计和调节是不与其他类型的常规治疗剂的可行性的机会。纳米载体增强药物对生物降解的稳定性,延长药物的循环时间,克服药物的溶解度的问题,并且可以进行微调为靶向药物递送和用于共输送显像剂1,2。基于纳米粒子输送系统持有癌症成像和治疗的承诺。肿瘤脉管系统是泄漏到大分子,并可能导致在通过增强的渗透性和保留(EPR)效果3肿瘤部位循环纳米颗粒的优先积累。间正在积极进行作为抗癌药物载体的几个纳米载体( 例如,脂质体,水凝胶,和聚合物胶束),聚合物胶束已超过第得到广泛普及Ë过去十年4,5。

聚合物胶束是一个热力学系统,该系统,在静脉内给药,可以潜在地稀释的临界胶束浓度(CMC)以下,从而导致它们的解离成unimers。交联的策略已被用于最小化胶束解离成unimers。但是,过分稳定胶束可以防止药物从靶部位释放,从而降低了整体的治疗效果。几种化学方法已被开发,以使交联降解响应于氧化还原或外界刺激,如还原的二硫键6,7-和pH裂解8或可水解酯键9,10。

我们以前曾报道了设计和由树突胆酸(CA)的块和线性聚乙二醇(PEG)共聚物,胶束纳米颗粒的合成称为末端树枝状聚合物(TD)11-15 </SUP>。这些TD被表示为PEG 了nK -CAy(其中n =分子量以千道尔顿(K),Y =(CA)的单位胆酸数)。他们封装药物的特点是体积小,保质期长,效率高,如疏水核心紫杉醇(PTX)和阿霉素(DOX)。 TD的积木,如PEG,赖氨酸,和CA,是生物相容的,和聚乙二醇电晕的存在可以赋予“隐形”纳米颗粒性质,防止胶束纳米颗粒的非特异性摄取被网状内皮系统。

巯基化线性树枝状聚合物可以很容易地通过引入半胱氨酸到我们的标准TD的树枝状寡聚赖氨酸骨干产生。本文介绍通过引入二硫键交联成阵的疏水性芯( 图1)用于生产可逆交联的胶束药物递送系统的一个浅显协议。

Protocol

伦理学声明:雌性无胸腺裸鼠(怒族/怒族株),6-8周龄,购然后根据指引AAALAC无病原体条件下保存,被允许适应环境之前的任何实验至少4天。根据协议号07-13119和09-15584号,由动物使用和注意事项管理咨询委员会在加州大学戴维斯分校的认可符合机构的指导方针所有的动物实验进行和。 1. TD PEG 5K -Cys合成4- -Ebes 8 -CA 8 在一个圆底烧瓶中…

Representative Results

制备与表征载药,二硫化交联胶束 两亲性聚合物的PEG 5K -Cys 4 -Ebes 8 -CA 8能够形成用于癌症的药物递送二硫化物交联的胶束体系的树枝状聚合物。在结构上,它被定义为通过一个支链聚(赖氨酸半胱氨酸EBES)主链相连的线性PEG分子(亲水域,分子量5K)的一端胆酸(疏水性结构域)的树枝状低聚物。存在使…

Discussion

几个纳米颗粒已经研究了其在药物递送的潜在用途。脂质体阿霉素和紫杉醇(PTX)-loaded人血清白蛋白的纳米聚集体用于癌症治疗由FDA批准的纳米治疗剂之中。然而,虽然临床上有效的,这两种纳米治疗剂的在尺寸上相对“大”,他们往往在肝脏和肺蓄积。具有相对较小的颗粒尺寸和较高的药物装载容量高分子胶束正在出现用于药物递送的纳米载体。其独特的核 – 壳结构“”溶解“'通过物理包?…

Declarações

The authors have nothing to disclose.

Acknowledgements

The authors thank Ms.Alisha Knudson for the editorial help. They would also like to acknowledge the financial support from the NIH/NCI (3R01CA115483, to K.S.L.), the DoD PRMRP Award (W81XWH-13-1-0490, to K.S.L.), the NIH/NCI (1R01CA199668, to Y.L.), and the NIH/NICHD (1R01HD086195, to Y.L.).

Materials

MeO-PEG5K-NH2 Rapp Polymere 125000-2
Fmoc-Lys(Fmoc)-OH Aaptec AFK107
Fmoc-Lys(Boc)-OH Anaspec AS-20132
Fmoc-Cys(Trt)-OH Aapptec AAC105
Dimethylformamide Fisher Scientific BP1160-4
Ethyl ether Fisher Scientific E134-20
N,N-Diisopropylethylamine Sigma Aldrich D125806
Trifluoroacetic acid Sigma Aldrich T6508 Corrosive, handle with care
4-methyl piperidine Alfa-Aesar L-02709
Ebes linker Anaspec AS-61924
Cholic acid Sigma Aldrich C1129
1,2-Ethanedithiol Sigma Aldrich 02390 Handle inside fume hood. Bleach gloves after usage
Triisopropylsilane Sigma Aldrich 233781
Chloroform (anhydrous) Sigma Aldrich 288306
Hydrogen peroxide solution 30% Aaron Industries NA
HoBt-Cl Aaptec CXZ096
DIC Sigma Aldrich D125407
Female athymic nude mice (Nu/Nu strain), 6–8 weeks age Harlan (Livermore, CA)

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Li, Y., Bharadwaj, G., Lee, J. S. A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles. J. Vis. Exp. (118), e54722, doi:10.3791/54722 (2016).

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