Name: preparation and characterization of individual and multi-drug loaded physically entrapped polymeric micelles
Uploaded: 2015-08-28T13:00:00.000+00:00
Duration: 7 min 32 s
Description: Watch this Scientific Journal Video about Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles at JoVE.com

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.

通过溶剂流延法1.准备个人与多药胶束的<ol><li>称取DTX 1毫克或EVR 1毫克或两种药物在每个1毫克的双药物胶束（DDM）。 </li><li>称取15毫克聚乙二醇2000 - B -PLA 1800或PEG 4000 - B -PLA 2200无论是个人或DDM。 </li><li>溶解药物/药物和聚合物在0.5毫升乙腈和地点在一个5毫升圆底烧瓶中。 </li><li>通过使用旋转蒸发器蒸发该药物（多个） - 聚合物乙腈减压溶液形成薄药物分布的聚合物膜。设定旋转蒸发器至100rpm，40℃的水浴温度和260毫巴进行5分钟，随后降低至100毫巴3个多分钟的真空压力。 </li><li>再水化用0.5ml去离子水的药物-聚合物膜在 50℃，轻轻摇动烧瓶以形成胶束。 </li><li>筛选结果通过0.2μm的尼龙过滤器荷兰国际集团胶束溶液，以除去任何未溶解的药物或污染物至1.5 ml离心管中。 </li></ol>用反相高效液相色谱（RP-HPLC）2.评估药物的装载及稳定性的胶束<ol><li>与equilibriated在40℃的等度模式用乙腈/水流动相（62/38）含有0.1％磷酸和1％甲醇以1ml / min的流速一个C8柱进行RP-HPLC分析和注射体积为10微升。 </li><li>经RP-HPLC分析，以确定初始载药量之前，在流动相100的稀释:新鲜配制的胶团（第1节）1。商店未稀释的个体微胶粒和DDM在室温（25℃）48小时，并准备新鲜1:100稀释的样品用流动相以通过RP-HPLC重新评估，并确定在24小时的药物（多个）稳定在胶束。 </li><li>分别监控DTX和EVR峰在227和279纳米为1.7和5.7分钟分别保留时间。执行一式三份的所有测量。目前的数据为平均±SD载药量。 </li></ol> 3.评估的胶束粒度的动态光散射（DLS） <ol><li>稀释新鲜制备的胶束在去离子水中以1:20的比例（如在第1节中描述），以得到最后的聚合物的1.5毫克/毫升浓度。 </li><li>测量He-Ne激光器（633纳米）的强度在173°，以确定散射。进行所有的测量在25℃以下预平衡2分钟。 </li><li>执行一式三份的所有测量。本数据作为平均数Z均尺寸±SD随着分布的多分散性指数（PDI）。 </li></ol> 在 4.评估的体外药物从个人胶束和DDM发布<ol><li>如第1装入2.5毫升胶束描述成3 ml的透析盒与制备单独的和胶束DDM7000克/ mol的分子量截止（MWCO）。 注意:此MWCO被选择，以使游离药物（多个）连同非关联聚合物分子自由扩散出带盒，从而保证漏槽条件。 </li><li>放置盒在2.5L的10mM的pH 7.4的磷酸盐缓冲液（制备稀释的库存的200mM溶液），并改变它的缓冲器，每3小时，以确保接收器的条件。保持缓冲器的在 37℃的温度在整个实验的持续时间。 </li><li>于0，0.5％，1，2，3，6，9，12，24，和48小时，撤回150微升在盒的溶液和替换用150微升新鲜缓冲液中。 </li><li>中所确定的第2条，以确定药物浓度分析用RP-HPLC样品。曲线拟合的基础上，使用stastitical软件一阶段的指数关联的简单扩散模型的药物（S）发布的数据。 </li><li>电子商务计算达到药物释放的50％所需要的时间（t 1/2）基于曲线拟合在个别胶束或DDM乙酰胆碱的药物。请在四组所有的测量。 </li></ol>

<ol>
	<li>Yokoyama, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymeric+micelles+as+a+new+drug+carrier+system+and+their+required+considerations+for+clinical+trials.">Polymeric micelles as a new drug carrier system and their required considerations for clinical trials.</a> Expert Opin Drug Deliv. 7, 145-158 (2010).</li><li>Shin, H. C., Alani, A. W., Rao, D. A., Rockich, N. C., Kwon, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-drug+loaded+polymeric+micelles+for+simultaneous+delivery+of+poorly+soluble+anticancer+drugs.">Multi-drug loaded polymeric micelles for simultaneous delivery of poorly soluble anticancer drugs.</a> J Control Release. 140, 294-300 (2009).</li><li>Adams, M. L., Lavasanifar, A., Kwon, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amphiphilic+block+copolymers+for+drug+delivery.">Amphiphilic block copolymers for drug delivery.</a> J Pharm Sci. 92, 1343-1355 (2003).</li><li>Oerlemans, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymeric+micelles+in+anticancer+therapy:+targeting,+imaging+and+triggered+release.">Polymeric micelles in anticancer therapy: targeting, imaging and triggered release.</a> Pharm Res. 27, 2569-2589 (2010).</li><li>Shin, H. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3-in-1+polymeric+micelle+nanocontainer+for+poorly+water-soluble+drugs.">A 3-in-1 polymeric micelle nanocontainer for poorly water-soluble drugs.</a> Mol Pharm. 8, 1257-1265 (2011).</li><li>Hasenstein, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antitumor+activity+of+Triolimus:+a+novel+multidrug-loaded+micelle+containing+Paclitaxel+Rapamycin,+and+17-AAG.">Antitumor activity of Triolimus: a novel multidrug-loaded micelle containing Paclitaxel Rapamycin, and 17-AAG.</a> Mol Cancer Ther. 11, 2233-2242 (2012).</li><li>Mazzaferro, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bivalent+sequential+binding+of+docetaxel+to+methyl-beta-cyclodextrin.">Bivalent sequential binding of docetaxel to methyl-beta-cyclodextrin.</a> Int J Pharm. 416, 171-180 (2011).</li><li>Iwase, Y., Maitani, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+in+vivo+evaluation+of+liposomal+everolimus+for+lung+carcinoma+and+thyroid+carcinoma.">Preparation and in vivo evaluation of liposomal everolimus for lung carcinoma and thyroid carcinoma.</a> Biol Pharm Bull. 35, 975-979 (2012).</li><li>Mishra, G. P., Doddapaneni, B. S., Nguyen, D., Alani, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antiangiogenic+effect+of+docetaxel+and+everolimus+as+individual+and+dual-drug-loaded+micellar+nanocarriers.">Antiangiogenic effect of docetaxel and everolimus as individual and dual-drug-loaded micellar nanocarriers.</a> Pharm Res. 31, 660-669 (2014).</li><li>Xu, W., Ling, P., Zhang, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymeric+micelles,+a+promising+drug+delivery+system+to+enhance+bioavailability+of+poorly+water-soluble+drugs.">Polymeric micelles, a promising drug delivery system to enhance bioavailability of poorly water-soluble drugs.</a> J Drug Deliv. 2013, 340315 (2013).</li><li>Lavasanifar, A., Samuel, J., Kwon, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(ethylene+oxide)-block-poly(L-amino+acid)+micelles+for+drug+delivery.">Poly(ethylene oxide)-block-poly(L-amino acid) micelles for drug delivery.</a> Adv Drug Deliv Rev. 54, 169-190 (2002).</li></ol>

The authors have nothing to disclose.

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...

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。

<table><tbody><tr><td>PEG2000-b-PLA1800</td><td>Advanced Polymer Materials, Inc</td><td>6-01- PLA/2000</td><td>PLA MW can be specified on ordering</td></tr><tr><td>PEG4000-b-PLA2200</td><td>Advanced Polymer Materials, Inc</td><td>6-01- PLA/4000</td><td>PLA MW can be specified on ordering</td></tr><tr><td>Docetaxel</td><td>LC Laboratories</td><td>D-1000</td><td>100 mg</td></tr><tr><td>Everolimus</td><td>LC Laboratories</td><td>E-4040</td><td>100 mg</td></tr><tr><td>Acetonitrile</td><td>EMD/VWR</td><td>EM-AX0145-1</td><td>HPLC grade; 4 L</td></tr><tr><td>Round bottom flask&amp;nbsp;</td><td>Glassco/VWR</td><td>89426-496</td><td>5 ml</td></tr><tr><td>RV 10 Control Rotary Evaporators</td><td>IKA Works</td><td>8025001</td><td>Rotoevaporator</td></tr><tr><td>Shimadzhu HPLC with DAD detector</td><td>Shimadzhu</td><td></td><td>RP-HPLC</td></tr><tr><td>Slide-a-lyzer dialysis casette MWCO 7000</td><td>Thermo Scientific, Inc</td><td>66370</td><td>3 ml</td></tr><tr><td>Phosphate buffer pH 7.4, 200 mM</td><td>VWR</td><td>100190-870</td><td>500 ml</td></tr><tr><td>Malvern NanoZS</td><td>Malvern Instruments, UK</td><td></td><td>DLS</td></tr><tr><td>Nylon filter</td><td>Acrodisc/VWR</td><td>28143-242</td><td>13 mm; 0.2&amp;micro;M</td></tr><tr><td>Phosphoric acid, NF</td><td>Spectrum Chemical/VWR</td><td>700000-626</td><td>100 ml</td></tr><tr><td>GraphPad Prism</td><td>&lt;a href=&quot;http://www.graphpad.com/&quot;&gt;www.graphpad.com&lt;/a&gt;</td><td></td><td>Analysis software</td></tr><tr><td>Zorbax SB-C8 Rapid Resolution cartridge&amp;nbsp;</td><td>Agilent Technologies</td><td>866953-906</td><td>4.6 &amp;times;75 mm, 3.5 &amp;#956;m</td></tr></tbody></table>

preparation and characterization of individual and multi-drug loaded physically entrapped polymeric micelles

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。

个别的DTX或EVR胶束及DTX和EVR DDM在PEG-b -PLA胶束成功配制在任一PEG 4000 - B -PLA 2200或PEG 2000 - B -PLA 1800（ 图1）。 DTX时，EVR和DDM显示了相似的稳定性在PEG 4000 - B -PLA 2200或PEG 2000 - B -PLA 1800超过48小时（ 图2）。 b -PLA 2200和PEG 2000 - -</e...

Watch this Scientific Journal Video about Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles at JoVE.com

Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

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.

制备及个体表征和多载药物理截留聚合物胶束

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar ...

preparation-characterization-individual-multi-drug-loaded-physically

Universidad San Sebastian

Research

JoVE Journal

Chemistry

11.2K 次观看.  Pacific University. 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.

视频: Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

A Facile and Efficient Approach for the Production of Reversible Disulfide Cross-linked Micelles

Nanomedicine is an emerging form of therapy that harnesses the unique properties of particles that are nanometers in scale for biomedical application. Improving drug delivery to maximize therapeutic outcomes and to reduce drug-associated side effects are some of the cornerstones of present-day nanomedicine. Nanoparticles in particular have found a wide application in cancer treatment. Nanoparticles that offer a high degree of flexibility in design, application, and production based on the tumor microenvironment are projected to be more effective with rapid translation into clinical practice. The polymeric micellar nano-carrier is a popular choice for drug delivery applications.
In this article, we describe a simple and effective protocol for synthesizing drug-loaded, disulfide cross-linked micelles based on the self-assembly of a well-defined amphiphilic linear-dendritic copolymer (telodendrimer, TD). TD is composed of polyethylene glycol (PEG) as the hydrophilic segment and a thiolated cholic acid cluster as the core-forming hydrophobic moiety attached stepwise to an amine-terminated PEG using solution-based peptide chemistry. Chemotherapy drugs, such as paclitaxel (PTX), can be loaded using a standard solvent evaporation method. The O2-mediated oxidation was previously utilized to form intra-micellar disulfide cross-links from free thiol groups on the TDs. However, the reaction was slow and not feasible for large-scale production. Recently, an H2O2-mediated oxidation method was explored as a more feasible and efficient approach, and it was 96 times faster than the previously reported method. Using this approach, 50 g of PTX-loaded, disulfide cross-linked nanoparticles have been successfully produced with narrow particle size distribution and high drug loading efficiency. The stability of the resulting micelle solution is analyzed using disrupting conditions such as co-incubation with a detergent, sodium dodecyl sulfate, with or without a reducing agent. The drug-loaded, disulfide cross-linked micelles demonstrated less hemolytic activity when compared to their non-cross-linked counterparts.

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.

可逆二硫键交联胶束生产的简便和有效途径

Nanomedicine is an emerging form of therapy that harnesses the unique properties of particles that are nanometers in scale for biomedical application. ...

科研

生物化学

Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale (nanoparticles). Nanoparticles can be engineered in a precise fashion where their size, composition and surface chemistry can be carefully controlled. This enables unprecedented freedom to modify some of the fundamental properties of their cargo, such as solubility, diffusivity, biodistribution, release characteristics and immunogenicity. Since their inception, nanoparticles have been utilized in many areas of science and medicine, including drug delivery, imaging, and cell biology1-4. However, it has not been fully utilized outside of "nanotechnology laboratories" due to perceived technical barrier. In this article, we describe a simple method to synthesize a polymer based nanoparticle platform that has a wide range of potential applications. 
The first step is to synthesize a diblock co-polymer that has both a hydrophobic domain and hydrophilic domain. Using PLGA and PEG as model polymers, we described a conjugation reaction using EDC/NHS chemistry5 (Fig 1). We also discuss the polymer purification process. The synthesized diblock co-polymer can self-assemble into nanoparticles in the nanoprecipitation process through hydrophobic-hydrophilic interactions.
The described polymer nanoparticle is very versatile. The hydrophobic core of the nanoparticle can be utilized to carry poorly soluble drugs for drug delivery experiments6. Furthermore, the nanoparticles can overcome the problem of toxic solvents for poorly soluble molecular biology reagents, such as wortmannin, which requires a solvent like DMSO. However, DMSO can be toxic to cells and interfere with the experiment. These poorly soluble drugs and reagents can be effectively delivered using polymer nanoparticles with minimal toxicity. Polymer nanoparticles can also be loaded with fluorescent dye and utilized for intracellular trafficking studies. Lastly, these polymer nanoparticles can be conjugated to targeting ligands through surface PEG. Such targeted nanoparticles can be utilized to label specific epitopes on or in cells7-10.

This article describes a nanoprecipitation method to synthesize polymer-based nanoparticles using diblock co-polymers. We will discuss the synthesis of diblock co-polymers, the nanoprecipitation technique, and potential applications.

制定通过Nanoprecipitation技术嵌段聚合物纳米粒子

Nanotechnology is a relatively new branch of science that involves harnessing the unique properties of particles that are nanometers in scale ...

生物工程

Preparation and Characterization of SDF-1&#945;-Chitosan-Dextran Sulfate Nanoparticles

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under appropriate conditions. The glycan nanoparticles are useful carriers for protein factors, which facilitate the in vivo delivery of the proteins and sustain their retention in the targeted tissue. The glycan polyelectrolyte complexes are also ideal for protein delivery, as the incorporation is carried out in aqueous solution, which reduces the likelihood of inactivation of the proteins. Proteins with a heparin-binding site adhere to dextran sulfate readily, and are, in turn, stabilized by the binding. These particles are also less inflammatory and toxic when delivered in vivo. In the protocol described below, SDF-1&#945; (Stromal cell-derived factor-1&#945;), a stem cell homing factor, is first mixed and incubated with dextran sulfate. Chitosan is added to the mixture to form polyelectrolyte complexes, followed by zinc sulfate to stabilize the complexes with zinc bridges. The resultant SDF-1&#945;-DS-CS particles are measured for size (diameter) and surface charge (zeta potential). The amount of the incorporated SDF-1&#945; is determined, followed by measurements of its in vitro release rate and its chemotactic activity in a particle-bound form.

The objective of this protocol is to incorporate SDF-1&#945;, a stem cell homing factor, into dextran sulfate-chitosan nanoparticles. The resultant particles are measured for their size and zeta potential, as well as the content, activity, and in vitro release rate of SDF-1&#945; from the nanoparticles.

SDF-1α - 壳聚糖硫酸葡聚糖纳米粒子的制备与表征

Chitosan (CS) and dextran sulfate (DS) are charged polysaccharides (glycans), which form polyelectrolyte complex-based nanoparticles when mixed under ...

化学

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

内部自组装脂质颗粒的简易制备碳纳米管稳定

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE). Characterization of the copolymer revealed a narrow molecular distribution (PDI &#60; 1.03) and confirmed the degree of polymerization of mPEG122-b-(PheGE)15. The critical micelle concentration of the copolymer was evaluated using an established fluorescence method with the aggregation behavior evaluated by dynamic light scattering and transmission electronic microscopy. The potential of the copolymer for use in drug delivery applications was evaluated in a preliminary manner including in vitro biocompatibility, loading and release of the hydrophobic anti-cancer drug doxorubicin (DOX). A stable micelle formulation of DOX was prepared with drug loading levels up to 14% (wt%), drug loading efficiencies &#62; 60% (w/w) and sustained release of drug over 4 days under physiologically relevant conditions (acidic and neutral pH, presence of albumin). The high drug loading level and sustained release is attributed to stabilizing &#960;-&#960; interactions between DOX and the core-forming block of the micelles.

The key steps of living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE) are described. The resulting block copolymer micelles (BCMs) were loaded with doxorubicin 14% (wt%) and sustained release of drug over 4 days under physiologically relevant conditions was obtained.

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

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl ...

Intra-lymph Node Injection of Biodegradable Polymer Particles

Generation of adaptive immune response relies on efficient drainage or trafficking of antigen to lymph nodes for processing and presentation of these foreign molecules to T and B lymphocytes. Lymph nodes have thus become critical targets for new vaccines and immunotherapies. A recent strategy for targeting these tissues is direct lymph node injection of soluble vaccine components, and clinical trials involving this technique have been promising. Several biomaterial strategies have also been investigated to improve lymph node targeting, for example, tuning particle size for optimal drainage of biomaterial vaccine particles. In this paper we present a new method that combines direct lymph node injection with biodegradable polymer particles that can be laden with antigen, adjuvant, or other vaccine components. In this method polymeric microparticles or nanoparticles are synthesized by a modified double emulsion protocol incorporating lipid stabilizers. Particle properties (e.g.&#160;size, cargo loading) are confirmed by laser diffraction and fluorescent microscopy, respectively. Mouse lymph nodes are then identified by peripheral injection of a nontoxic tracer dye that allows visualization of the target injection site and subsequent deposition of polymer particles in lymph nodes. This technique allows direct control over the doses and combinations of biomaterials and vaccine components delivered to lymph nodes and could be harnessed in the development of new biomaterial-based vaccines.

Lymph nodes are the immunological tissues that orchestrate immune response and are a critical target for vaccines. Biomaterials have been employed to better target lymph nodes and to control delivery of antigens or adjuvants. This paper describes a technique combining these ideas to inject biocompatible polymer particles into lymph nodes.

可生物降解聚合物颗粒的淋巴内结注射

Generation of adaptive immune response relies on efficient drainage or trafficking of antigen to lymph nodes for processing and presentation of these ...

Assembly and Characterization of Polyelectrolyte Complex Micelles

Polyelectrolyte complex micelles (PCMs), core-shell nanoparticles formed by self-assembly of charged polymers in aqueous solution, provide a powerful platform for exploring the physics of polyelectrolyte interactions and also offer a promising solution to the pressing problem of delivering therapeutic oligonucleotides in vivo. Developing predictive structure-property relationships for PCMs has proven difficult, in part due to the presence of strong kinetic traps during nanoparticle self-assembly. This article discusses criteria for choosing polymers for PCM construction and provides protocols based on salt annealing that enable assembly of repeatable, low-polydispersity nanoparticles. We also discuss PCM characterization using light scattering, small-angle X-ray scattering, and electron microscopy.

We provide protocols and representative data for designing, assembling, and characterizing polyelectrolyte complex micelles, core-shell nanoparticles formed by polyelectrolytes and hydrophilic charged-uncharged block copolymers.

聚电解质复合微晶体的组装与特性

Polyelectrolyte complex micelles (PCMs), core-shell nanoparticles formed by self-assembly of charged polymers in aqueous solution, provide a powerful ...

Preparation and Characterization of Lipophilic Doxorubicin Pro-drug Micelles

Micelles have been successfully used for the delivery of anticancer drugs. Amphiphilic polymers form core-shell structured micelles in an aqueous environment through self-assembly. The hydrophobic core of micelles functions as a drug reservoir and encapsulates hydrophobic drugs. The hydrophilic shell prevents the aggregation of micelles and also prolongs their systemic circulation in vivo. In this protocol, we describe a method to synthesize a doxorubicin lipophilic pro-drug, doxorubicin-palmitic acid (DOX-PA), which will enhance drug loading into micelles. A pH-sensitive hydrazone linker was used to conjugate doxorubicin with the lipid, which facilitates the release of free doxorubicin inside cancer cells. Synthesized DOX-PA was purified with a silica gel column using dichloromethane/methanol as the eluent. Purified DOX-PA was analyzed with thin layer chromatography (TLC) and 1H-Nuclear Magnetic Resonance Spectroscopy (1H-NMR). A film dispersion method was used to prepare DOX-PA loaded DSPE-PEG micelles. In addition, several methods for characterizing micelle formulations are described, including determination of DOX-PA concentration and encapsulation efficiency, measurement of particle size and distribution, and assessment of in vitro anticancer activities. This protocol provides useful information regarding the preparation and characterization of drug-loaded micelles and thus will facilitate the research and development of novel micelle-based cancer nanomedicines.

A protocol for the preparation and characterization of lipophilic doxorubicin pro-drug loaded 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG) micelles is described.

制备和表征亲脂阿霉素前药胶束

Micelles have been successfully used for the delivery of anticancer drugs. Amphiphilic polymers form core-shell structured micelles in an aqueous ...

Phase Change Dimethyldioctadecylammonium-Shelled Microdroplets as a Promising Drug Delivery System: Results on 3D Spheroids of Mammalian Tumor Cells

Significant improvement of phase-change perfluorocarbon microdroplets (MDs) in the vast theranostic scenario passes through the optimization of the MDs composition with respect to synthesis efficiency, stability, and drug delivery capability. To this aim, decafluoropentane (DFP) MDs stabilized by a shell of dimethyldioctadecylammonium bromide (DDAB) cationic surfactant were designed. A high concentration of DDAB-MDs was readily obtained within a few seconds by pulsed high-power insonation, resulting in low polydisperse 1 &#181;m size droplets. Highly positive &#950;-potential, together with a long, saturated hydrocarbon chains of the DDAB shell, are key factors to stabilize the droplet and the drug cargo therein. The high affinity of the DDAB shell with cell plasma membrane allows for localized chemotherapeutics delivery by increasing the drug concentration at the tumor cell interface and boosting the uptake. This would turn DDAB-MDs into a relevant drug delivery tool exhibiting high antitumor activity at very low drug doses.
In this work, the efficacy of such an approach is shown to dramatically improve the effect of doxorubicin against 3D spheroids of mammalian tumor cells, MDA-MB-231. The use of&#160;three-dimensional (3D) cell cultures developed in the form of multicellular tumor spheroids (i.e., densely packed cells in a spherical shape) has numerous advantages compared to 2D cell cultures: in addition to have the potential to bridge the gap between conventional in vitro studies and animal testing, it will improve the ability to perform more predictive in vitro screening assays for preclinical drug development or evaluate the potential of off-label drugs and new co-targeting strategies.

Decafluoropentane microdroplets developed with a shell of dimethyldioctadecylammonium bromide exhibited an exceptional colloidal stability and an actractive biointerface. DDAB-MDs proved to be efficient drug reservoirs characterized by a high affinity to plasma membranes together with enhanced uptake and antitumor activity of Doxorubicin against human triple-negative breast cancer (MDA-MB-231) 3D model.

Significant improvement of phase-change perfluorocarbon microdroplets (MDs) in the vast theranostic scenario passes through the optimization of the MDs ...

Preparation and Characterization of Nanoliposomes for the Entrapment of Bioactive Hydrophilic Globular Proteins

Liposome nanocapsules have been applied for many purposes in the pharmaceutical, cosmetic, and food industries. Attributes of liposomes include their biocompatibility, biodegradability, non-immunogenicity, non-toxicity, and ability to entrap both hydrophilic and hydrophobic compounds. The classical hydration of thin lipid films in an organic solvent is applied herein as a technique to encapsulate tarin, a plant lectin, in nanoliposomes. Nanoliposome size, stability, entrapment efficiency, and morphological characterization are described in detail. The nanoliposomes are prepared using 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (ammonium salt; DSPE-MPEG 2000), and cholesterylhemisuccinate (CHEMS) as the main constituents. Lipids are first dissolved in chloroform to obtain a thin lipid film that is subsequently rehydrated in ammonium sulfate solution containing the protein to be entrapped and incubated overnight. Then, sonication and extrusion techniques are applied to generate nanosized unilamellar vesicles. The size and polydispersity index of the nanovesicles are determined by dynamic light scattering, while nanovesicle morphology is assessed by scanning electron microscopy. Entrapment efficiency is determined by the ratio of the amount of unencapsulated protein to original amount of initially loaded protein. Homogeneous liposomes are obtained with an average size of 155 nm and polydispersity index value of 0.168. A high entrapment efficiency of 83% is achieved.

This study describes classical hydration using the thin lipid film method for nanoliposome preparation followed by nanoparticle characterization. A 47 kDa-hydrophilic and globular protein, tarin, is successfully encapsulated as a strategy to improve stability, avoid fast clearance, and promote controlled release. The method can be adapted to hydrophobic molecules encapsulation.

生物活性亲水球状蛋白的纳米脂质体制备与表征

Liposome nanocapsules have been applied for many purposes in the pharmaceutical, cosmetic, and food industries. Attributes of liposomes include their ...