Name: environmentally-controlled microtensile testing of mechanically-adaptive polymer nanocomposites for ex vivo characterization
Uploaded: 2013-08-20T08:55:55
Description: Watch this Scientific Journal Video about Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization at JoVE.com

Эта работа была поддержана Департаментом биомедицинской инженерии в Case Western Reserve University через обе лаборатории запуска средства (J. Capadona) и Medtronic стипендий (К. Поттер). Дополнительное финансирование на этом исследовании была частично поддержана грантом NSF ECS-0621984 (С. Zorman), Case Ассоциации выпускников (С. Zorman), Департамент по делам ветеранов через Премия заслуги обзора (B7122R), а также Advanced Платформа технический центр (C3819C).

1. Подготовка образцов <ol><li> Подготовьте ПВА-NC пленки толщиной в диапазоне 25-100 мкм, с использованием литья решения и технологии сжатия 10-12. </li><li> Придерживаться пленки на кремниевой пластине при нагревании на горячей плите в течение двух минут при 70 ° С (выше температуры стеклован?...

<ol>
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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+of+brain+tissue+to+chronically+implanted+neural+electrodes.">Response of brain tissue to chronically implanted neural electrodes.</a> Journal of Neuroscience Methods. 148, 1-18 (2005).</li><li>Subbaroyan, J., Kipke, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+in+Medicine+and+Biology+Society,+2006.">Engineering in Medicine and Biology Society, 2006.</a> , 3588-3591 (2006).</li><li>Harris, J., Capadona, J., Miller, R., Healy, B., Shanmuganathan, K., Rowan, S., Weder, C., Tyler, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanically+adaptive+intracortical+implants+improve+the+proximity+of+neuronal+cell+bodies.">Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies.</a> Journal of Neural Engineering. 8, 066011 (2011).</li><li>Capadona, J. R., Shanmuganathan, K., Tyler, D. J., Rowan, S. J., Weder, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-Responsive+Polymer+Nanocomposites+Inspired+by+the+Sea+Cucumber+Dermis.">Stimuli-Responsive Polymer Nanocomposites Inspired by the Sea Cucumber Dermis.</a> Science. 319, 1370-1374 (2008).</li><li>Shanmuganathan, K., Capadona, J. R., Rowan, S. J., Weder, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-Responsive+Mechanically+Adaptive+Polymer+Nanocomposites.">Stimuli-Responsive Mechanically Adaptive Polymer Nanocomposites.</a> ACS Applied Materials &amp; Interfaces. 2, 165-174 (2009).</li><li>Shanmuganathan, K., Capadona, J. R., Rowan, S. 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P., Hess, A. E., Rowan, S. J., Weder, C., Zorman, C. A., Tyler, D. J., Capadona, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+deployment+of+mechanically+adaptive+nanocomposites+for+intracortical+microelectrodes.">In vivo deployment of mechanically adaptive nanocomposites for intracortical microelectrodes.</a> Journal of Neural Engineering. 8, 046010 (2011).</li><li>Shanmuganathan, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Bio-inspired Stimuli-responsive Mechanically Dynamic Nanocomposites. , (2010).</li><li>Rousche, P. J., Pellinen, D. S., Pivin, D. P., Williams, J. C., Vetter, R. J., Kipke, D. 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P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+a+comparison+of+microelectrodes+for+acute+and+chronic+recordings.">Toward a comparison of microelectrodes for acute and chronic recordings.</a> Brain Research. 1282, 183-200 (2009).</li><li>Lin, J. M., Chang, P. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Novel+Remote+Health+Monitor+with+Replaceable+Non-Fragile+Bio-Probes+on+RFID+Tag.">A Novel Remote Health Monitor with Replaceable Non-Fragile Bio-Probes on RFID Tag.</a> Applied Mechanics and Materials. 145, 415-419 (2012).</li><li>Kunzelman, K. 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Продвижение имплантируемых биомедицинских микроэлектромеханических систем (BioMEMS) для взаимодействия с биологическими системами мотивирует развитие новых материалов с высокой заданными свойствами. Некоторые из этих материалов предназначены для демонстрируют изменение свойств мат?...

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalogue Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Silicon wafer</td>
			<td>University Wafer</td>
			<td>&nbsp;</td>
			<td>Mechanical grade</td>
		</tr>
		<tr>
			<td>Extruded acrylic sheet</td>
			<td>Professional Plastics</td>
			<td>SACR 062EF</td>
			<td>Thickness 0.062"</td>
		</tr>
		<tr>
			<td>Razor blade</td>
			<td>McMaster-Carr</td>
			<td>3962A3</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tweezers</td>
			<td>McMaster-Carr</td>
			<td>8384A47</td>
			<td>#5 tip</td>
		</tr>
		<tr>
			<td>Super Glue Gel</td>
			<td>Loctite</td>
			<td>130380</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Air Brush</td>
			<td>Snap-on Industrial</td>
			<td>BF175TA</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Air Compressor</td>
			<td>Paasche</td>
			<td>B002YKN8YO</td>
			<td>D500</td>
		</tr>
		<tr>
			<td>Thermocouple</td>
			<td>Omega</td>
			<td>HH12A</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Hot plate</td>
			<td>Cimarec</td>
			<td>SP131325Q</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>CO2 direct-write laser</td>
			<td>VersaLaser</td>
			<td>3.5</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Dessicator</td>
			<td>Fisher Scientific</td>
			<td>08-595</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Lamp</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>custom-built</td>
		</tr>
		<tr>
			<td>Microtensile tester</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>custom-built</td>
		</tr>
	</tbody>
</table>

environmentally-controlled microtensile testing of mechanically-adaptive polymer nanocomposites for ex vivo characterization

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, each offering its own advantages and shortcomings5,6. Most prominently, due to the microscale device dimensions, a high modulus is required to facilitate implantation into living tissue. Conversely, the stiffness of the device should match the surrounding tissue to minimize induced local strain7-9. Therefore, we recently developed a new class of bio-inspired materials to meet these requirements by responding to environmental stimuli with a change in mechanical properties10-14. Specifically, our poly(vinyl acetate)-based nanocomposite (PVAc-NC) displays a reduction in stiffness when exposed to water and elevated temperatures (e.g. body temperature). Unfortunately, few methods exist to quantify the stiffness of materials in vivo15, and mechanical testing outside of the physiological environment often requires large samples inappropriate for implantation. Further, stimuli-responsive materials may quickly recover their initial stiffness after explantation. Therefore, we have developed a method by which the mechanical properties of implanted microsamples can be measured ex vivo, with simulated physiological conditions maintained using moisture and temperature control13,16,17. 
To this end, a custom microtensile tester was designed to accommodate microscale samples13,17 with widely-varying Young's moduli (range of 10 MPa to 5 GPa). As our interests are in the application of PVAc-NC as a biologically-adaptable neural probe substrate, a tool capable of mechanical characterization of samples at the microscale was necessary. This tool was adapted to provide humidity and temperature control, which minimized sample drying and cooling17. As a result, the mechanical characteristics of the explanted sample closely reflect those of the sample just prior to explantation.
The overall goal of this method is to quantitatively assess the in vivo mechanical properties, specifically the Young's modulus, of stimuli-responsive, mechanically-adaptive polymer-based materials. This is accomplished by first establishing the environmental conditions that will minimize a change in sample mechanical properties after explantation without contributing to a reduction in stiffness independent of that resulting from implantation. Samples are then prepared for implantation, handling, and testing (Figure 1A). Each sample is implanted into the cerebral cortex of rats, which is represented here as an explanted rat brain, for a specified duration (Figure 1B). At this point, the sample is explanted and immediately loaded into the microtensile tester, and then subjected to tensile testing (Figure 1C). Subsequent data analysis provides insight into the mechanical behavior of these innovative materials in the environment of the cerebral cortex.

Механические свойства практически всех полимерных материалов, в том числе наши ПВА-NC, зависят от воздействия окружающей среды. В частности, они включают воздействием тепла и влаги. Когда материал является пластифицированный благодаря поглощению влаги или претерпевает фазовый перехо?...

Watch this Scientific Journal Video about Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization at JoVE.com

Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

Метод обсуждается в котором<em&gt; В естественных условиях</em&gt; Механические свойства раздражителей аспекты материалов как функцию времени. Образцы испытывают<em&gt; Экс естественных условиях</em&gt; Использование microtensile тестер с экологическим контролем для имитации физиологической среде. Эта работа способствует дальнейшему пониманию<em&gt; В естественных условиях</em&gt; Поведение нашем материале.

Экологически-контролируемое Microtensile Тестирование Механически адаптивных полимерных нанокомпозитов для<em&gt; Экс естественных условиях</em&gt; Характеристика

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, ...

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Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

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Decades ago the human placenta was thought to be an impenetrable barrier between mother and unborn child. However, the discovery of thalidomide-induced ...

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

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Визуализация денатурированного коллагена Пряди<em&gt; В естественных условиях</em&gt; И<em&gt; Экс естественных</em&gt; Через Фото-срабатывает гибридизации скованного Коллаген Mimetic пептидов

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

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Генерация масштабируемой, металлик высоких-Aspect Ratio нанокомпозитов в биологическом жидкой среде

The goal of this protocol is to describe the synthesis of two novel biocomposites with high-aspect ratio structures. The biocomposites consist of copper ...

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Биомеханическое Характеристика мягких тканей человека с помощью отступов и испытания на растяжение

Regenerative medicine aims to engineer materials to replace or restore damaged or diseased organs. The mechanical properties of such materials should ...

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Новая модель Ex Vivo для оценки работы эндоскопической подслизистую инъекционного материала

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential ...

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Neonatal brachial plexus palsy (NBPP) is a stretch injury that occurs during the birthing process in nerve complexes located in the neck and shoulder ...