Name: particles without a box: brush-first synthesis of photodegradable peg star polymers under ambient conditions
Uploaded: 2013-10-10T21:30:00
Description: Watch this Scientific Journal Video about Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions at JoVE.com

我们感谢化学的麻省理工学院和麻省理工学院林肯实验室的高级概念委员会支持这项工作。

我们首先描述从3 kDa的O-（2 -氨基乙基）聚乙二醇（PEG-NH 2）和降冰片烯基-N-羟基琥珀酰亚胺（NHS）酯，PEG-MM B中的合成和纯化。前者化合物可自Sigma Aldrich公司购买，或根据文献方法22,23通过阴离子聚合制得。后者化合物可以在两个步骤中，根据已发布的程序21来制备。接下来，我们描述了从市售格拉布斯第二代催化剂的合成催化剂<strong...

<ol>
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刷一BASP合成的关键优势是独特的能力，快速合成不同大小和组成的纳米结构并行而不需要专门的设备。在本研究中，我们证明了刷第一合成方法，使用降冰片烯官能化的PEG大分子单体（B，图1）和一个双-降冰片烯硝基苄酯交联剂（C，图1）。从B中的PEG链赋予水溶性的最终BASP结构。对硝基苄基交联剂是光降解。 这是一...

纳米粒子的聚合物已被广泛研究其作为平台用于药物递送，支持催化，生物成像，并自组装1-3的潜在用途。现代应用要求纳米粒子合成是轻便，重现性好，化学功能兼容，并服从多样化4,5。应变烯烃的开环复分解聚合（ROMP）是一个功能强大的方法论的官能聚合物的纳米结构具有受控尺寸和窄的质量分布1,6〜8的合成。例如，降冰片烯官能化的聚（乙二醇）（PEG）大分子单体（MMS）可以有效地通过ROMP聚合生成水溶性的瓶刷聚合物。使用这种方法，即携带多个可释放的药物分子，荧光团，和自旋造影剂的纳米结构可迅速地并在平行6，9，10制备。 只读存储器磷已也被用于“臂先”合成星形聚合物。在臂先法，线性聚合物是交联的多官能交联剂，得到球形纳米结构聚合物臂。施罗克和同事报道了第一臂先ROMP合成星形聚合物的通过降冰片烯，dicarbomethoxynorbornadiene，并与双官能交联剂的降冰片烯三甲基甲硅烷保护的dicarboxynorbornene线性聚合物的交联。11,12 Buchmeiser已扩展这种方法对材料的合成与的应用范围，其中包括支持催化，组织工程和层析13-17。大谷和他的同事已经通过相关的“输入-输出”聚合战略18，19做星形聚合物纳米粒子与功能性的表面。 大多数臂先聚合涉及单体，聚合物和明星偶联反应之间复杂的相互作用。钍通过这通常会导致较宽的分子量（MW）的分布逐步增长机构E后者的收益。为了克服这一限制在相关臂先原子转移自由基聚合反应，Matyjaszewski等人进行的预制聚合物的MM臂先交联，以提供星形聚合物具有非常窄的分子量分布20。在这种情况下，空间体积的MM中，和星武器的比例增加至起始位点，抑制控制不佳星+星型连接器的进程，并导致为生，环比增长机制。 当我们试图在同一策略中ROMP的具有降冰片烯封端的PEG-MM和一个双 - 降冰片烯的交联剂的情况下，星形聚合物具有非常广泛的，多模态分子量分布得到。这一结果表明，在该系统中，单独的MM不够笨重抑制星形+星形耦合。为了增加空间体积的明星武器，并有可能限制这种uncontroLLED耦合，我们试图先聚合的MM，形成瓶刷聚合物，在没有交联剂，然后加入交联剂。我们很高兴地发现，在一定条件下，这种“刷第一”的方法提供了简单的访问“刷臂星形聚合物”（BASPs）与窄分子量分布和可调谐的核心和电晕功能。 最近，我们报道了刷第一ROMP合成使用格拉布斯第三代催化剂A（图1）21 PEG BASPs的。在这项工作中，PEG-MM B暴露催化剂 A产生的生活刷大分子引发剂与定义的骨架长度（B 1，图1）。 乙 1等分转移到含有不同量的交联剂的C小瓶启动BASP形成。的分子量，并且BASPs的，因此大小，几何形状增加了用C的添加量。我们提供了一种机理假设对于此几何级数增长过程，并证明功能性，氮氧化物芯和电晕标记BASPs可以容易，而不需要后聚合改性的步骤或顺序添加单体制备。然而，在所有的报道的例子中，我们关注的催化剂失活，我们进行了手套箱内氮气气氛下，所有的反应。 由于我们的初步报告中，我们发现，刷第一种方法是非常有效的从广泛的降冰片烯终止彩信和功能交联剂形成BASPs的。我们还发现，该方法可以在台式执行没有特殊的预防措施，以除去空气或水分。 此处，一系列不同分子量和脱乙酰三BASPs将SY通过刷子先法在环境条件下nthesized。简言之，10当量乙的将被暴露在15分钟1.0当量的催化剂A（图1a），以产生一个BI与平均聚合度为10（DP）。三等分这批商业智能的将被转移的C 20 的当量（N， 图1b），以含有10，15分开的小瓶，和。 4小时后，聚合反应将通过添加乙基乙烯基醚淬灭。星形聚合物兆瓦和分子量分布将使用凝胶渗透色谱仪配备有一个多角度激光光散射检测器（GPC-MALLS）进行表征。

<table border="0" cellpadding="0" cellspacing="0" width="592">
	<colgroup>
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		<col />
	</colgroup>
	<tbody>
		<tr height="42">
			<td height="84" rowspan="2" style="height:84px;width:216px;">Grubbs Second Generation Catalyst</td>
			<td rowspan="2" style="width:91px;">Materia (or Sigma Aldrich)</td>
			<td rowspan="2" style="width:119px;">C848 (Sigma Aldrich: 569747)</td>
			<td style="width:167px;">
			Used as purchased from manufacturer. 
 *Provided as a generous gift.
			</td>
		</tr>
		<tr height="42">
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pyridine</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">270970</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">O-(2-aminoethyl)polyethylene glycol 3000</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">07969</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">PEG-MM</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21, protocol 1)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">norbornene-N-hydroxysuccinimidyl (NHS) ester</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Bis-norb-NBOC Crosslinker</td>
			<td style="width:91px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:167px;">Synthesized following reported procedures (Ref. 21)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Pentane</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">158941</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Tetrahydrofuran (HPLC grade)</td>
			<td style="width:91px;">Sigma Aldrich </td>
			<td style="width:119px;">34865</td>
			<td style="width:167px;">Dried and purified over a solvent purification columns </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Dichloromethane</td>
			<td style="width:91px;">VWR </td>
			<td>BDH1113-4LG</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Acetonitrile (HPLC grade)</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">34998</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Acetic Acid </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">A6283</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Sodium sulfate </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td>239313</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Diethyl ether</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">673811</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Dimethylformamide (HPLC grade) </td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">270547</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Lithium Bromide</td>
			<td style="width:91px;">Sigma Aldrich</td>
			<td style="width:119px;">213225</td>
			<td style="width:167px;">Used as purchased from manufacturer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">MillQ Biocel A10</td>
			<td style="width:91px;">Millipore</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Beckmann Coulter HPLC (127p solvent module, 166p detector)</td>
			<td style="width:91px;">Beckmann Coulter</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Zorbax 300SB-C18 PrepHT reverse phase column </td>
			<td style="width:91px;">Agilent</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">1260 Infinity Liquid Chromatography </td>
			<td style="width:91px;">Agilent</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">GPC KD-806M column</td>
			<td style="width:91px;">Shodex</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dawn Heleos II Light Scatterer</td>
			<td style="width:91px;">Wyatt</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Optilab T-rEX Refractive Index Detector</td>
			<td style="width:91px;">Wyatt</td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass Scintillation Vials - 40 ml</td>
			<td style="width:91px;">Chemglass</td>
			<td>CG-4909-05</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Glass Scintillation Vials - 4 ml </td>
			<td style="width:91px;">Chemglass</td>
			<td style="width:119px;">CG-4904-06</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Glass Scintillation Vials (PTFE-lined cap) - 2 ml </td>
			<td style="width:91px;">Agilent</td>
			<td>5183-4518</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Stir-bars</td>
			<td style="width:91px;">VWR</td>
			<td style="width:119px;">5894x</td>
			<td style="width:167px;">various sizes </td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">13 mm 0.45 &#181;m Nylon Syringe filter</td>
			<td style="width:91px;">PerkinElmer</td>
			<td>02542903</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">13 mm 0.45 &#181;m polytetrafluoroethylene syringe filter</td>
			<td style="width:91px;">PerkinElmer</td>
			<td>02542909</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">1 ml disposable syringes </td>
			<td style="width:91px;">VWR</td>
			<td style="width:119px;">53548-001</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Swing bucket centrifuge or similar</td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;">Should be able to reach approximately 4,000 rpm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Round bottom flask</td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fritted glass filter assembly </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Rotary Evaporator </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Balance </td>
			<td style="width:91px;"> </td>
			<td style="width:119px;"> </td>
			<td style="width:167px;"> </td>
		</tr>
	</tbody>
</table>

particles without a box: brush-first synthesis of photodegradable peg star polymers under ambient conditions

便利的方法多样功能化纳米粒子的快速，平行合成，使发现新配方的药物释放，生物成像，并支持催化作用。在这份报告中，我们展示了刷臂星形聚合物（BASP）纳米粒子的“刷第一”的方法平行合成。在该方法中，降冰片烯封端的聚（乙二醇）（PEG）大分子单体（PEG-MM）通过开环易位聚合反应（ROMP）的第一聚合以生成一个活刷大分子引发剂。这引发剂原液等分试样加入到含有不同量的光分解双降冰片烯交联剂的小瓶。暴露在交联剂引发了一系列动力学控制刷+刷和明星+明星偶合反应，最终产生BASPs与内核由聚乙二醇组成的交联剂和电晕的。最终BASP大小取决于交联剂的添加量。我们开展同步论文对没有特殊的预防措施以消除空气和水分的台式3 BASPs。该样品的特征在于用凝胶渗透色谱（GPC）;结果密切同意与我们以前的灵活运用惰性（手套箱）条件的报告。关键的实际特征，优点和刷第一方法的潜在缺点进行了讨论。

图2示出的GPC迹线用于各种从B1，B2和B3制备BASPs的。在所有情况下，该数据表明，增加交联剂（N）的当量导致增加的BASP的大小。由于观察到在我们以前的报告中，10当量的交联剂是不足以实现统一BASPs;在N = 10的样品显示了一个清楚的多模态跟踪的GPC用大量残留聚合物刷，特别是在未纯化的MM B1的情况下（ 图2...

Watch this Scientific Journal Video about Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions at JoVE.com

Particles without a Box: Brush-first Synthesis of Photodegradable PEG Star Polymers under Ambient Conditions

聚（乙二醇）（PEG）的电刷臂的星形聚合物（BASPs）与窄质量分布及可调谐纳米级的大小是通过PEG-降冰片烯大分子单体随后将得到的生活的各部分的传递的开环易位聚合（ROMP）合成刷引发剂含有不同量的刚性，光可切割双降冰片烯交联剂的小瓶。

颗粒无箱：可光降解的PEG星形聚合物在环境条件刷第一个合成

Convenient methods for the rapid, parallel synthesis of diversely functionalized nanoparticles will enable discovery of novel formulations for drug ...

Research

JoVE Journal

Chemistry

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions

Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions

Mizoroki-哎呀交叉偶联反应由二氯{双[1,1&#39;，1&#39;&#39;  - （phosphinetriyl）tripiperidine]}钯催化在温和的反应条件

Dichloro-bis(aminophosphine) complexes of palladium with the general formula of [(P{(NC5H10)3-n(C6H11)n})2Pd(Cl)2] (where n = 0-2), belong to a new family ...

科研

化学

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

根据环境条件的金纳米粒子的稳定低聚簇的大小控制合成的一种简便方法

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Visualization of Ambient Mass Spectrometry with the Use of Schlieren Photography

环境质谱可视化纹影摄影的使用

This manuscript outlines how to visualize mass spectrometry ambient ionization sources using schlieren photography. In order to properly optimize the mass ...

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

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 ...

Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

在环境环境中制备具有或不具有介孔MCM-41的超细氢氧化铝颗粒

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis ...

Facet-to-facet Linking of Shape-anisotropic Colloidal Cadmium Chalcogenide Nanostructures

形状-各向异性胶体镉硫纳米结构的 Facet-to-facet 连接

Here, we describe a protocol that allows for shape-anisotropic cadmium chalcogenide nanocrystals (NCs), such as nanorods (NRs) and tetrapods (TPs), to be ...

Phase Behavior of Charged Vesicles Under Symmetric and Asymmetric Solution Conditions Monitored with Fluorescence Microscopy

用荧光显微镜监测对称和非对称溶液条件下带电泡的相行为

Phase-separated giant unilamellar vesicles (GUVs) exhibiting coexisting liquid-ordered and liquid-disordered domains are a common biophysical tool to ...

Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications

核壳镧系掺杂转换纳米晶的合成及其在蜂窝中的应用

Lanthanide-doped upconversion nanocrystals (UCNs) have attracted much attention in recent years based on their promising and controllable optical ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

电化学阻抗谱作为电化学速率常数估计的一种工具

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

[4.4] 刺环氧基的固相合成

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...