Name: magnetic and thermal-sensitive poly(n-isopropylacrylamide)-based microgels for magnetically triggered controlled release
Uploaded: 2017-07-04T14:00:00
Description: Watch this Scientific Journal Video about Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release at JoVE.com

这项工作得到台湾科技部（MOST 104-2221-E-131-010，MOST 105-2622-E-131-001-CC2）的财政支持，部分得到原子分子科学研究所的支持，中央研究院

1.表面改性，水分散磁性纳米粒子，Fe 3 O 4和Fe 3 O 4 -NH 2的合成<ol><li>加入14.02g FeCl 3，8.6g FeCl 2 ·4H 2 O和250mL水加入到500mL烧杯中。 </li><li>连接转子和控制器，进行机械搅拌。将溶液在室温（RT）下以300rpm混合30分钟。 </li><li>在室温下向溶液中加入25mL氢氧化铵（33％），并保持搅拌（300rpm）30分钟。保持烧杯开放。 小心：如果吸入，氢?...

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制备的最重要步骤在方案第2节中，用于通过热诱导乳液合成磁性微凝胶。 如图2 （TEM图）所示，由于由PNIPAAm（酰胺基），PEI（胺基）之间的强H键而产生的物理交联，微凝胶的球形结构可以保持在RT（低于LCST）和Fe 3 O 4 -NH 2 （胺基）。基于图4的比较，磁性微凝胶在低（25℃）或高（70℃）温度下良好分散。微凝胶也可以由磁体?...

水凝胶是三维（3D）聚合物网络，其不能溶解但可在水溶液中溶胀1 。聚合物网络具有亲水结构域（其可以水合以提供水凝胶结构）和交联构象（其可以防止网络崩溃）。已经研究了制备水凝胶的各种方法，例如乳液聚合，阴离子共聚，相邻聚合物链的交联和反相微乳液聚合2 。通过这些方法引入物理和化学交联以获得结构稳定的水凝胶1,3 。化学交联通常需要连接聚合物的主链或侧链的交联剂的参与。与化学交联相比，物理交联是fabr的更好选择<html>由于这些试剂对于实际应用而言通常是有毒的，因此避免了交联剂的酸化水凝胶。已经研究了几种用于合成物理交联水凝胶的方法，例如用离子相互作用的交联，结晶，两亲嵌段之间的键合或聚合物链上的接枝以及氢键4,5,6,7。 近来，受不同环境条件（ 即温度，pH，光，离子强度和磁场）影响的构象，化学或物理性能变化的刺激敏感性聚合物近来引起了人们的注意，作为控制释放系统的潜在平台，药物输送和抗癌治疗8,9 ，xref“&gt; 10,11,12 ，研究人员正在关注热敏聚合物，其中可以容易地控制固有温度PNIPAAm是一种热敏聚合物，其含有亲水性酰胺基和疏水性异丙基，并且具有较低的临界溶解温度（LCST） 13 。酰胺基和水分子之间的氢键在低温下（低于LCST）提供了PNIPAAm在水溶液中的分散性，而聚合物链之间的氢键在高温（高于LCST）下发生，并且不包括水分子，使得聚合物网络崩溃，关于这种独特的性质，已经出版了许多报道，通过调节聚合物链长度的疏水性和亲水性比例如共聚，接枝或侧链来制备温度触发的自组装水凝胶，制药连锁改造cal平台14,15,16,17 。 磁性材料如铁，钴和镍在过去几十年中也受到越来越多的关注，用于生物化学应用18 。在这些候选物中，由于其稳定性和低毒性，氧化铁被广泛使用。纳米级铁氧化物立即响应于磁场并表现为超顺磁性原子。然而，这样的小颗粒容易聚集;这降低了表面能，因此失去了分散性。为了提高水分散性，接枝或涂层以保护层通常不仅用于分离每个单独的颗粒以获得稳定性，而且还使反应位点进一步官能化。 在这里，我们制造了基于PNIPAAm的磁性微型凝胶作为控制释放系统的药物载体。合成过程如图1所示。代替复杂的共聚和化学交联，采用PNIPAAm的新型温度诱导乳液进行物理交联，得到无需附加表面活性剂或交联剂的微凝胶。这简化了合成并防止了不期望的毒性。在这种简单的制备方案中，合成的微凝胶为磁性氧化铁纳米颗粒和疏水性抗癌药物姜黄素提供了水分散性。 FT-IR，TEM和成像提供了分散和包封的证据。由于嵌入的Fe 3 O 4 -NH 2 ，磁性微凝胶显示出在HFMF下作为控制释放的微器件的潜力。

<table border="0" cellpadding="0" cellspacing="0" width="773">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:311px;">Poly(N-isopropylacrylamide)</td>
			<td style="width:139px;">Polyscience, Inc</td>
			<td style="width:119px;">21458-10</td>
			<td style="width:205px;">Mw~40000</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">(3-aminopropyl)trimethoxysilane</td>
			<td>Sigma-Aldrich</td>
			<td>440140</td>
			<td>&#62; 99 %</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Iron(II) chloride tetrahydrate</td>
			<td>Sigma-Aldrich</td>
			<td>44939</td>
			<td>99%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Iron(III) chloride</td>
			<td>Sigma-Aldrich</td>
			<td>157740</td>
			<td>97%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Curcumin</td>
			<td>Sigma-Aldrich</td>
			<td>00280590</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ammonia hydroxide</td>
			<td>Fisher Chemical</td>
			<td>A/3240/PB15</td>
			<td>35%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Phosphate Buffered Saline</td>
			<td>Sigma-Aldrich</td>
			<td>806552</td>
			<td>pH 7.4, liquid, sterile-filtered</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Polyethylenimine (PEI)</td>
			<td>Sigma-Aldrich</td>
			<td>P3143</td>
			<td>50 % (w/v) in water</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">High-frequency magnetic field (HFMF)</td>
			<td>Lantech Industrial Co., Ltd.,Taiwan</td>
			<td>LT-15-80</td>
			<td>15 kV, 50&#8211;100 kHz</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultraviolet-Visible Spectrophotometry</td>
			<td>Thermo Scientific Co.</td>
			<td>Genesys</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Transmission electron microscopy (TEM)</td>
			<td>JEM-2100</td>
			<td>JEOL</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fourier transform infrared spectroscopy (FTIR)</td>
			<td>PerkinElmer</td>
			<td>Spectrum 100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thermogravimetric analyzer</td>
			<td>PerkinElmer</td>
			<td>Pyris 1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ultrasonic cell disruptor</td>
			<td>Hielscher Ultrasonics</td>
			<td>UP50H</td>
			<td></td>
		</tr>
	</tbody>
</table>

magnetic and thermal-sensitive poly(n-isopropylacrylamide)-based microgels for magnetically triggered controlled release

设计并制造了具有包封的抗癌药物姜黄素（Cur）的磁感和热敏聚（ N-异丙基丙烯酰胺）（PNIPAAm）/ Fe 3 O 4 -NH 2微凝胶用于磁触发释放。通过温度诱导的乳液制备具有球形结构的基于PNIPAAm的磁性微凝胶，然后通过混合PNIPAAm，聚乙烯亚胺（PEI）和Fe 3 O 4 -NH 2磁性纳米粒子进行物理交联。由于其分散性，将Fe 3 O 4 -NH 2纳米颗粒嵌入聚合物基质内。暴露在Fe 3 O 4 -NH 2和PEI表面上的胺基通过与PNIPAAm的酰胺基团物理交联来支撑球形结构。疏水性抗癌药物姜黄素在包封入微凝胶后可以分散在水中。表征微凝胶通过透射电子显微镜（TEM），傅里叶变换红外光谱（FT-IR）和UV-Vis光谱分析。此外，在外部高频磁场（HFMF）下研究了磁触发释放。由于磁感应加热（热疗）效应，将HFMF应用于微凝胶后，观察到姜黄素的显着“爆发”。该手稿描述了Cur-PNIPAAm / Fe 3 O 4 -NH 2包封的姜黄素的磁触发控制释放，其可以潜在地用于肿瘤治疗。

PNIPAAm / PEI / Fe 3 O 4 -NH 2微凝胶的合成示意图如图1所示。应用TGA估计有机化合物相对于整个微凝胶的相对组成。由于只有有机化合物PNIPAAm可以燃烧，因此确定了PNIPAAm和Fe 3 O 4 （或Fe 3 O 4 -NH 2 ）的相对组成，如表1所示。为什么PNIPAAm / Fe 3 O 4 -NH 2微?...

Watch this Scientific Journal Video about Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release at JoVE.com

Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release

该手稿描述了通过温度诱导的乳液制备磁性和热敏性微凝胶而没有化学反应。通过混合聚（ N-异丙基丙烯酰胺）（PNIPAAm），聚乙烯亚胺（PEI）和Fe 3 O 4 -NH 2纳米粒子来合成这些敏感微凝胶，用于磁和热触发药物释放的潜在用途。

磁性和热敏性聚（<em&gt;ñ</em基于异丙基丙烯酰胺）的微凝胶用于磁触发控制释放

Magnetically and thermally sensitive poly(N-isopropylacrylamide) (PNIPAAm)/Fe3O4-NH2 microgels with the encapsulated anti-cancer drug curcumin (Cur) were ...

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Magnetic and Thermal-sensitive Poly(N-isopropylacrylamide)-based Microgels for Magnetically Triggered Controlled Release

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Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer ...

Imaging Denatured Collagen Strands In vivo and Ex vivo via Photo-triggered Hybridization of Caged Collagen Mimetic Peptides

Imaging Denatured Collagen Strands In vivo and Ex vivo via Photo-triggered Hybridization of Caged Collagen Mimetic Peptides

成像变性的胶原股<em&gt;在体内</em&gt;和<em&gt;体外</em&gt;通过光引发杂交笼胶原蛋白仿生肽

Collagen is a major structural component of the extracellular matrix that supports tissue formation and maintenance. Although collagen remodeling is an ...

Magnetic Tweezers for the Measurement of Twist and Torque

磁性镊子的扭曲和扭矩的测量

Single-molecule techniques make it possible to investigate the behavior of individual biological molecules in solution in real time. These techniques ...

Custom-designed Laser-based Heating Apparatus for Triggered Release of Cisplatin from Thermosensitive Liposomes with Magnetic Resonance Image Guidance

定制设计的基于激光的加热装置顺铂触发释放的热敏脂质体与磁共振成像制导

Liposomes have been employed as drug delivery systems to target solid tumors through exploitation of the enhanced permeability and retention (EPR) effect ...

Composite Scaffolds of Interfacial Polyelectrolyte Fibers for Temporally Controlled Release of Biomolecules

界面聚电解质纤维的生物分子在时间控释复合支架

Various scaffolds used in tissue engineering require a controlled biochemical environment to mimic the physiological cell niche. Interfacial ...

Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release

交变磁场敏感的混合明胶微凝胶药物控释

Magnetically-responsive nano/micro-engineered biomaterials that enable a tightly controlled, on-demand drug delivery have been developed as new types of ...

An Additive Manufacturing Technique for the Facile and Rapid Fabrication of Hydrogel-based Micromachines with Magnetically Responsive Components

一种简便快速制备磁响应元件的水凝胶基微型机械的添加剂制造技术

Polyethylene glycol (PEG)-based hydrogels are biocompatible hydrogels that have been approved for use in humans by the FDA. Typical PEG-based hydrogels ...

Generating Controlled, Dynamic Chemical Landscapes to Study Microbial Behavior

生成受控动态化学景观，研究微生物行为

We demonstrate a method for the generation of controlled, dynamic chemical pulses&#8213;where localized chemoattractant becomes suddenly available at the ...

Magnetic-, Acoustic-, and Optical-Triple-Responsive Microbubbles for Magnetic Hyperthermia and Pothotothermal Combination Cancer Therapy

磁性、声学和光学三响应性微泡，用于磁性高温和波托托热组合癌症治疗

The precision delivery of anti-cancer agents which aim for targeted and deep-penetrated delivery as well as a controlled release at the tumor site has ...