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 border="0" cellpadding="0" cellspacing="0">
	<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&#160;</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&#181;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><a href="http://www.graphpad.com/">www.graphpad.com</a></td>
			<td></td>
			<td>Analysis software</td>
		</tr>
		<tr>
			<td>Zorbax SB-C8 Rapid Resolution cartridge&#160;</td>
			<td>Agilent Technologies</td>
			<td>866953-906</td>
			<td>4.6 &#215;75mm, 3.5 micron</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

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

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid phase by using combinatorial chemistry. One of the most well studied classes of peptidomimetics is peptoids. Peptoids are easy to synthesize and have been shown to be proteolysis-resistant and cell-permeable. Over the past decade, many useful protein ligands have been identified through screening of peptoid libraries. However, most of the ligands identified from peptoid libraries do not display high affinity, with rare exceptions. This may be due, in part, to the lack of chiral centers and conformational constraints in peptoid molecules. Recently, we described a new synthetic route to access peptide tertiary amides (PTAs). PTAs are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. With side chains on both &#945;-carbon and main chain nitrogen atoms, the conformation of these molecules are greatly constrained by sterical hindrance and allylic 1,3 strain. (Figure 1) Our study suggests that these PTA molecules are highly structured in solution and can be used to identify protein ligands. We believe that these molecules can be a future source of high-affinity protein ligands. Here we describe the synthetic method combining the power of both split-and-pool and sub-monomer strategies to synthesize a sample one-bead one-compound (OBOC) library of PTAs.

Peptide tertiary amides (PTAs) are a superfamily of peptidomimetics that include but are not limited to peptides, peptoids and N-methylated peptides. Here we describe a synthetic method which combines&#160;both split-and-pool and sub-monomer strategies to synthesize a one-bead one-compound library of PTAs.

分裂和池合成及肽叔酰胺图书馆表征

Peptidomimetics are great sources of protein ligands. The oligomeric nature of these compounds enables us to access large synthetic libraries on solid ...

科研

化学

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

功能化的合成与表征金属 - 有机骨架

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

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.

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

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 ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子胶体的合成与表征

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors

Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and flexibility of their emission properties can be achieved by controlling their composition and dopants. However, a lot of work is still required to improve their properties and to reduce the production cost. A possible approach is to correlate the luminescence properties of the Sialon particles with their local structural and chemical environment in order to optimize their growth parameters and find novel phosphors. For such a purpose, the low-voltage cathodoluminescence (CL) microscopy is a powerful technique. The use of electron as an excitation source allows detecting most of the luminescence centers, revealing their luminescence distribution spatially and in depth, directly comparing CL results with the other electron-based techniques, and investigating the stability of their luminescence properties under stress. Such advantages for phosphors characterization will be highlighted through examples of investigation on several Sialon phosphors by low-energy CL.

Low-energy Cathodoluminescence for OxyNitride Phosphors

An excellent chemical and luminescence stabilities of (oxy)nitride phosphors present it as an promising alternative to currently used sulfide and oxide phosphors. In this paper, we present the way to investigate its local luminescence properties using low-energy cathodoluminescence (CL).

低能量的阴极射线（氧）氮化物荧光粉

Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and ...

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

使用Photoredox催化剂蠕虫状胶束的简便合成可见光介导的分散聚合

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

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.

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

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 ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

环状聚合物的合成及其在熔融状态扩散运动的表征在单分子水平

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing

Effective hair dyeing through in situ incubation of keratin hair with the products of fungal laccase-catalyzed polymerization of plant phenols has been previously demonstrated. However, the dyeing process takes a long time to complete compared to commercial hair-dyeing products. To overcome this bottleneck, pre-synthesized polymeric products of the oxidative reaction of Trametes versicolor laccase on catechin and catechol, either with or without mordant agents (e.g., FeSO4), were here employed to achieve permanent keratin hair dyeing in various colors and shades. The laccase action in acidic sodium acetate buffer led to a deep black coloration after coupling reactions between the plant phenols. The colored dye products were then desalted and concentrated with ultrafiltration. The dyes, with or without mordant agents, caused a significant increase in &#916;E values (i.e., color difference value) in gray human hair within 2.5 hours. In addition, different keratin colors and shades were induced depending upon the mordanting and pH changes. The dyed hair also exhibited a strong resistance to detergent treatments, indicating that our methods can give rise to permanent hair dyeing.&#160;Overall, our work has provided novel insight into developing eco-friendly hair-dyeing methods as alternatives to commercial toxic diamine-based dyes.

Here, we present a protocol to use pre-synthesized polymeric products derived from fungal laccase-catalyzed polymerization of plant phenols, either with or without mordant agents (e.g., FeSO4), to induce detergent-resistant keratin hair dyeing within 2.5 hours.

对于直接或媒介为基础的头发染色厂苯酚衍生的高分子染料的合成

Effective hair dyeing through in situ incubation of keratin hair with the products of fungal laccase-catalyzed polymerization of plant phenols has been ...

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

Paramagnetic complexes of gadolinium(III) with acyclic or macrocyclic chelates are the most commonly used contrast agents (CAs) for magnetic resonance imaging (MRI). Their purpose is to enhance the relaxation rate of water protons in tissue, thus increasing the MR image contrast and the specificity of the MRI measurements. Current clinically approved contrast agents are low molecular weight molecules that are rapidly cleared from the body. The use of dendrimers as carriers of paramagnetic chelators can play an important role in the future development of more efficient MRI contrast agents. Specifically, the increase in local concentration of the paramagnetic species results in a higher signal contrast. Furthermore, this CA provides a longer tissue retention time due to its high molecular weight and size. Here, we demonstrate a convenient procedure for the preparation of macromolecular MRI contrast agents based on poly(amidoamine) (PAMAM) dendrimers with monomacrocyclic DOTA-type chelators (DOTA &#8211; 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate). The chelating unit was appended by exploiting the reactivity of the isothiocyanate (NCS) group towards the amine surface groups of the PAMAM dendrimer to form thiourea bridges. Dendrimeric products were purified and analyzed by means of nuclear magnetic resonance spectroscopy, mass spectrometry, and elemental analysis. Finally, high resolution MR images were recorded and the signal contrasts obtained from the prepared dendrimeric and the commercially available monomeric agents were compared.

Preparation and In Vitro Characterization of Dendrimer-based Contrast Agents for Magnetic Resonance Imaging

This protocol describes the preparation and characterization of a dendrimeric magnetic resonance imaging (MRI) contrast agent that carries cyclen-based macrocyclic chelates coordinating paramagnetic gadolinium ions. In a series of MRI experiments in vitro, this agent produced an amplified MRI signal when compared to the commercially available monomeric analogue.

制备及<em&gt;体外</em&gt;磁共振成像基于树状大分子造影剂的表征

Paramagnetic complexes of gadolinium(III) with acyclic or macrocyclic chelates are the most commonly used contrast agents (CAs) for magnetic resonance ...