一个两亲性共聚物的阴离子聚合通过π-π堆积作用稳定嵌段共聚物胶束的制备
Summary
生活在甲氧基聚乙二醇（MPEG-b -PPheGE）苯基缩水甘油醚（PheGE）的阴离子聚合的关键步骤进行说明。将所得嵌段共聚物胶束（带宽模型）的下生理学上得到有关条件装载阿霉素14％（重量％）和药物的持续释放超过4天。
Abstract
在这项研究中，包括与苯基成形芯嵌段的两亲共聚物由甲氧基聚乙二醇（MPEG-b -PPheGE）活苯基缩水甘油醚（PheGE）的阴离子聚合来合成。该共聚物的表征揭示了窄的分子量分布（PDI <1.03），并确认的mPEG 122的聚合度- B – （PheGE）15。使用具有通过动态光散射和透射电子显微镜计算的聚集行为建立荧光法，共聚物的临界胶束浓度进行评价。该共聚物为在药物输送应用中使用的潜力，它初步包括体外生物相容性，装载和疏水性抗癌药物多柔比星（DOX）的释放进行评价。阿霉素的稳定胶束制剂与载药量高达14％（重量％），载药effici制备encies> 60％（W / W）4天以上生理学相关条件（酸性和中性pH值，白蛋白的存在）根据药物的和持续释放。高载药量水平和持续释放归因于稳定DOX和胶束的形成芯块之间的π-π相互作用。
Introduction
在含水介质中，两亲性嵌段共聚物组装形成纳米尺寸的嵌段共聚物胶束（带宽模型），该组成由亲水壳或电晕包围的疏水核。胶束核心可作为疏水性药物的结合的贮存器;同时，亲水电晕提供核心和外部介质之间的界面。聚（乙二醇）（PEG）和其衍生物是聚合物的最重要的一个类和最广泛使用的药物制剂之一。1-3带宽模型已经被证明是一个值得药物递送平台，靠这个几个配方现在在后期临床开发技术。4最常见的，该共聚物的疏水性嵌段包含聚己内酯，聚（D，L-丙交酯），聚（环氧丙烷）或聚（β-苄基-L-天门冬氨酸）的5 -9
片冈的研究小组调查了来自PEO-b形成球形胶束</em> -PBLA和聚（环氧乙烷） – B -用于递送阿霉素（DOX）10,11在他们的报告中（聚天冬氨酸共轭多柔比星），他们提出了在聚合物缀合的药物或PBLA之间的π-π相互作用和游离DOX用于稳定导致在药物装载和保留增加胶束芯。它建立了药物和成芯块之间的相容性或相互作用是关键性能相关的参数的决定因素。12除了DOX，一些癌症治疗包括其核心结构（ 例如 ，甲氨蝶呤，olaparib，SN内芳环-38）。
其结果存在这样包括在其芯成形块苄环共聚物的合成显著兴趣。 PEG和其衍生物的阴离子开环聚合使以上分子量的控制，导致以良好的收率低多分散性的材料。13,14 Ethyle与苯基缩水甘油醚（PheGE）或氧化苯乙烯NE氧化物（SO）可以是（共）聚合以形成形成胶束为疏水性药物溶解嵌段共聚物。15-18目前的报告描述了活苯基的阴离子聚合的必要步骤缩水甘油基上的mPEG-OH醚单体作为大分子引发剂（ 图1）。然后将所得嵌段共聚物和它的聚集体的特征在于相关于药物递送用的特性方面。
Protocol
图1.示意图，显示了MPEG-b -PPheGE共聚物的制备九个关键步骤。 请点击此处查看该图的放大版本。 1.受干燥天气影响的试剂准备 试剂的制备。 在烘箱中在50℃下称重15克的mPEG-5K（M N =5400克/摩尔，PDI 1….
Representative Results
图3. 苯基缩水甘油醚的基于MPEG大分子引发剂阴离子聚合的插图制作MPEG- 期 B – （PheGE）15 制备嵌段共聚物胶束的阿霉素的装载示意图使用萘钾说明了羟基的mPEG的去质子化。作为自由基阴离子，其次是苯基缩水甘油醚（PheGE）单体?…
Discussion
由于良好的控制了阴离子聚合提供了对分子量它是业界最实用的流程的基础上环氧乙烷单体（PEG和PPG）聚合物的制备方法之一。必须使用最佳和严格的条件为，以实现成功的聚合。所有试剂和适当的装置的严格纯化是用于合成的活性质至关重要。当前设置的限制大多与依赖于插管传输技术相关。使用适当的压力，插管是为学术设置一个安全的实验室规模的技术。施加这些预防措施将提供更好的在?…
Declarações
The authors have nothing to disclose.
Acknowledgements
CA acknowledges a Discovery grant from the Natural Sciences and Engineering Research Council of Canada. CA acknowledges a Chair in Pharmaceutics and Drug Delivery from GSK. The authors declare no competing financial interest.
Materials
| DMEM/HAMF12 | Gibco, Life Technologies | 12500 | Supplemented with 10%FBS. Warm in 37 °C water bath |
|||||
| Trypsin-EDTA(0.25%) | Sigma-Aldrich | T4049 | Warm in 37 °C water bath | |||||
| Fetal bovine serum (FBS) | Sigma-Aldrich | F1051 | Canada origin | |||||
| MDA-MB-468 cell line | ATCC | HTB-132 | ||||||
| MTS tetrazolium reagent | PROMEGA | G111B | ||||||
| Phenazine ethosulfate (PES) | Sigma-Aldrich | P4544 | >95% | |||||
| mPEG5K (Mn 5400 g/mol) | Sigma-Aldrich | 81323 | PDI=1.02 | |||||
| Dimethylsolfoxide (DMSO) | Sigma-Aldrich | D4540 | >99.5% | |||||
| Naphthalene | Sigma-Aldrich | 147141 | >99% | |||||
| Phenyl glycidyl ether | Sigma-Aldrich | A32608 | >85% | |||||
| Benzophenone | Sigma-Aldrich | 427551 | >99% | |||||
| Potassium | Sigma-Aldrich | 451096 | >98% | |||||
| Tetrahydrofuran | Caledon Laboratory Chemicals | 8900 1 | ACS | |||||
| Hexane | Caledon Laboratory Chemicals | 5500 1 | ACS | |||||
| Calcium hydride (CaH2) | ACP | C-0460 | >99.5% | |||||
| Diethyl Ether | Caledon Laboratory Chemicals | 1/10/4800 | ACS | |||||
| Microplate reader | BioTek Instruments | |||||||
| Differential scanning calorimetry (DSC) | TA Instruments Inc | DSC Q100 | ||||||
| Gel permeation chromatography (GPC) | Waters | 2695 separation moldule / 2414 detector | 2 Columns: Agilent Plgel 5µm Mixed-D | |||||
| NMR spectroscopy | Varian Mercury 400MHz | |||||||
| Chloroform-d | Sigma-Aldrich | 151858 | 99.96% | |||||
| DMSO-d | Sigma-Aldrich | 156914 | 99.96% | |||||
| Vaccum pump | Gardner Denver Welch Vacuum Tech, Inc. | Ultimate pressure 1.10-4 torr | ||||||
| Drierit with indicator, 8 mesh | Sigma-Aldrich | 238988 | Regenerated at 230°C for 2 hrs | |||||
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Citar este artigo
Le Dévédec, F., Houdaihed, L., Allen, C. Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions. J. Vis. Exp. (116), e54422, doi:10.3791/54422 (2016).