制备及个体表征和多载药物理截留聚合物胶束
Summary
The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.
Abstract
像polyethyleneglycol- 块 -polylactic酸（PEG-B-PLA）两亲性嵌段共聚物可以自组装成胶束高于临界胶束浓度形成由亲水壳在水环境包围着的疏水核心。这些胶束的核心可以利用来加载疏水性的，水溶性差的药物，如多西他赛（DTX）和依维莫司（EVR）。的胶束结构和药物装载能力系统的表征之前是重要的体外和体内研究可以进行。本文所描述的协议的目标是提供必要的特征步骤，以实现规范化胶束制品。 DTX和EVR有1.9和9.6微克固有溶解度/ ml的分别可通过溶剂浇铸这增加DTX和EVR的水溶性，以分别1.86和1.85毫克/毫升来实现这些胶束的制备。在胶束的eval药物稳定性uated在室温下超过48小时表明药物的97％或更多保留在溶液中。胶束粒度，使用动态光散射评估，并表明，这些胶束的尺寸低于50纳米，取决于聚合物的分子量。用汇条件下透析在pH值7.4，在37℃下超过48小时的胶束释药进行了评估。曲线拟合结果表明，药物释放是由表明它是扩散驱动的第一顺序流程驱动。
Introduction
具有重复结构的两亲嵌段共聚物的亲水和疏水结构域的组成可以自发自组装，以形成被称为聚合物胶束三维大分子装配体。这些结构具有内疏水核由亲水壳包围。疏水芯具有或者通过物理截留通过疏水相互作用或由上到聚合物骨架化学缀合到掺入疏水性药物的能力。1许多优势存在，使用这些嵌段共聚物形成胶束用于药物递送。这些包括掺入难溶性药物，提高了掺入药物的药代动力学，和生物相容性和/或生物降解性聚合物的使他们安全的替代品常规增溶剂。2采用高分子胶束的另一个优点是它们的胶体粒径，15-之间150纳米3，使他们每年有吸引力renteral交付。因此，在过去的20年聚合物胶束已经成为可行的药物递送系统对水难溶性药物特别是用于癌症治疗。3,4-
目前有五个聚合胶束制剂用于癌症治疗正在进行临床试验。4四个在临床试验中的胶束是基于PEG的嵌段共聚物，而最后是含有聚环氧乙烷三嵌段共聚物。这些微胶粒的大小而变化，从20纳米至85纳米。使用基于PEG的聚合物的优点是它们的生物相容性和因第二块上也可以是可生物降解的。最近基于polyethyleneglycol- 块 -polylactic酸（PEG-b -PLA）聚合物胶束新药物递送系统已被开发用于并发递送多种抗癌药物。在PEG-B- PLA胶束都是生物相容性和生物降解。这些多药胶束已示出为在体外和体内2,5,6-不同癌症模型ynergistic抑制和配合到利用多种药物的化疗，以防止电阻和降低毒性的当前范例。因此，存在大量的在制备和用于癌症和其它疾病状态使用表征这些胶束药物递送系统的兴趣。
在下面的工作我们提出由这种胶束可以制备和表征评价他们的利益疾病状态之前，一步一步的过程。对于这项工作的目的2难溶于抗癌剂，多西紫杉醇（DTX）和依维莫司（EVR）已被选定。既DTX和EVR是水溶性差的化合物与固有水溶解度在1.9和9.6微克/ ml的分别。7,8-二PEG-不同分子量b -PLA聚合物在这个协议中被用作配制的聚合物的积木胶束，这些聚合物聚乙二醇2000 – B -PLA 1800（3800道尔顿）和PEG 4000 – B -PLA 2200（6200道尔顿）。因此，PEG-b -PLA胶束可以提供一个独特的平台作为纳米载体的DTX和EVR单独和组合。所需的试剂/材料和设备需要准备和表征这些胶束列于表1。
Protocol
Representative Results
Discussion
The use of polymeric micelles for drug delivery continues to expand due to their versatility and ability to deliver hydrophobic drugs for various disease states. Therefore, the techniques needed to prepare and characterize these formulations prior to use in cell culture or animals is a critical first step to determine the best pairing between the drug and the polymer. PEG-b-PLA are excellent amphiphilic block copolymers for drug delivery purposes. However, the block length of the hydrophilic and hydrophobic s…
Disclosures
The authors have nothing to disclose.
Acknowledgements
This study was supported by the grant from AACP New Pharmacy Faculty Research Award Program, Medical Research Foundation of Oregon New Investigator Grant, Oregon State University-Startup fund, and Pacific University, School of Pharmacy Start-up fund.
Materials
| PEG2000-b-PLA1800 | Advanced Polymer Materials, Inc | 6-01- PLA/2000 | PLA MW can be specified on ordering |
| PEG4000-b-PLA2200 | Advanced Polymer Materials, Inc | 6-01- PLA/4000 | PLA MW can be specified on ordering |
| Docetaxel | LC Laboratories | D-1000 | 100 mg |
| Everolimus | LC Laboratories | E-4040 | 100 mg |
| Acetonitrile | EMD/VWR | EM-AX0145-1 | HPLC grade; 4 L |
| Round bottom flask | Glassco/VWR | 89426-496 | 5 mL |
| RV 10 Control Rotary Evaporators | IKA Works | 8025001 | Rotoevaporator |
| Shimadzhu HPLC with DAD detector | Shimadzhu | RP-HPLC | |
| Slide-a-lyzer dialysis casette MWCO 7000 | Thermo Scientific, Inc | 66370 | 3 mL |
| Phosphate buffer pH 7.4 200 mM | VWR | 100190-870 | 500 mL |
| Malvern NanoZS | Malvern Instruments, UK | DLS | |
| Nylon filter | Acrodisc/VWR | 28143-242 | 13 mm; 0.2µM |
| Phosphoric acid, NF | Spectrum Chemical/VWR | 700000-626 | 100 mL |
| GraphPad Prism | www.graphpad.com | Analysis software | |
| Zorbax SB-C8 Rapid Resolution cartridge | Agilent Technologies | 866953-906 | 4.6 ×75mm, 3.5 micron |
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