这项工作是由赠款的援助从教育部，文化，体育，日本的科学技术，京都技术科学中心，和三谷的基础研究与发展青年科学家（16K17956）的支持。

1.仪器<ol><li> 偏振元件 <ol><li>为了构建一个偏振装置，提供具有卤素灯，导光，偏振器，一个样品台，光学轨道，杆架，和一个数字单镜头反光照相机（光源参见偏振图1C和材料清单装置部分）。 </li></ol></li></ol> 2.生物聚合物溶液的制备<ol><li> 多糖溶液 <ol><li>通过在〜80℃下搅拌超过12小时溶解SACRAN 7（0.5g）在纯水（100mL）中。在溶解，用保鲜膜覆盖，以防止蒸发容器。制备的黄原胶以同样的方式的水溶液。 </li><li>在〜25℃下冷却该溶液，以获得0.5重量％的水溶液。 </li><li>离心SACRAN溶液以除去杂质（48400×g下，4℃，1个小时，3添ES）。 </li></ol></li><li> MT解决方案 <ol><li>在的Britton-Robinson缓冲液制备0.5重量％的微管蛋白溶液（1毫升）（80mM的哌嗪N，N&#39; -双（2-乙磺酸）（PIPES）; 1mM的乙二醇-双（β氨基乙醚） - N，N，N &#39;N&#39;，N&#39;-四乙酸（EGTA）;在冰上8和5mM MgCl 2的，pH为6.8）。 </li><li>使用0.5重量％的微管蛋白溶液（50μL）和鸟苷-5&#39; - [（α，β）-methyleno]三磷酸（GpCpp）（5μL），制备含GpCpp微管蛋白溶液（50微升）。孵育在37℃下3小时，以获得稳定的核MT。 注:GpCpp的作用是支持MT形成和完全抑制MT的解聚微管蛋白。 </li><li>混合在约25℃的0.5重量％的微管蛋白溶液（950μL）和含GpCpp微管蛋白溶液（50μL）1天，以获得一个稳定的0.5重量％溶液MT。 </li></ol></li><li> DNA溶液<ol><li>准备在Tris-EDTA缓冲溶液中的0.5重量％的DNA溶液（1毫升）（10毫摩尔Tris，pH8.0中，用1mM EDTA）中。 </li></ol></li><li>保持0.5重量％的生物聚合物的样品溶液在25℃下为干燥实验。 </li></ol> 3，干燥下交叉偏振光实验和观察<ol><li> 在单侧打开的细胞溶液（图1A） <ol><li>切断的硅片（参见材料列表）成厚度为1mm的适当形状（5-15毫米1毫米内部尺寸，以及约20毫米; 图1A）。 <ol><li>组装用的5-15毫米1毫米内尺寸的硅隔离物构成的单侧开放单元，和约20毫米和两个非修饰的载玻片（76 1mm×1mm的×26毫米）。修正了双剪辑池的两边事先保留样品溶液泄漏。 </li></ol></li><li>慢慢添加的每个使用〜1毫米孔径的移液管的0.5重量％的生物聚合物溶液（100-300μL）的TE尖端给每个小区在〜25℃。使用注射器针头将细胞去除气泡。 </li><li>放置细胞与在60℃下用于蒸发大气压力下在空气循环的烘箱蒸镀方向是相反的重力。 </li></ol></li><li> 下交叉偏振光观测（图1B-1C） <ol><li>通过具有平坦表面光源在很宽的区域（80毫米×80mm）中一个100瓦的卤素灯提供直的可见光。调整偏振器使用保持器（ 图1C）在45°和135°。 </li><li>固定使用光学轨道和杆支架（ 图1C）的光源，偏振器，样品台，和照相机的位置。放置在两个偏振器之间的样品台（偏振片之间的距离应为约5厘米）。将相机约20厘米的样品台上，以允许聚焦。 </li><li>在给定时间，将样品从步骤3.1.3 POLA之间上平行于XZ平面的阶段rizers并覆盖有黑色帘装置;实际装置被示于图1C中 。 </li><li>拍摄通过线性交叉的偏振器使用的数字单镜头反射式照相机用标准变焦镜头的样品（见材料列表）。控制照相机设置，例如焦距，使用计算机软件（参见材料列表）。 </li></ol></li><li> 透射光强度的空间-时间分析（图1C） <ol><li>为了评估在干燥过程中的取向序参数的变化，收集照片每小时24小时。 </li><li>测量沿着作为使用图像处理程序（ 例如，使用ImageJ）的灰度值在Z方向上的中心线的透射光强度。 </li><li>画出从上开口侧的距离的函数的灰度值的曲线图。 </li></ol></li><li> 交叉极化二极管灯下显微观察吨（图1D） <ol><li>要检查的方法中，使显微观察用配有CCD照相机9的偏光显微镜。保持一阶延迟板在光路中。控制使用PC软件的照片的条件。 </li></ol></li></ol>

<ol>
	<li>Flemming, H. -. C., Wingender, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biofilm+matrix.">The biofilm matrix.</a> Nat. Rev. Microbiology. 8 (9), 623-633 (2010).</li><li>Osada, Y., Kawamura, R., Sano, 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> Hydrogels of cytoskeletal proteins. , (2016).</li><li>Rothemund, P. W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Folding+DNA+to+create+nanoscale+shapes+and+patterns.">Folding DNA to create nanoscale shapes and patterns.</a> Nature. 440, 297-302 (2006).</li><li>Okeyoshi, K., Okajima, M. K., Kaneko, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Milliscale+self-integration+of+megamolecule+biopolymers+on+a+drying+gas-aqueous+liquid+crystalline+interface.">Milliscale self-integration of megamolecule biopolymers on a drying gas-aqueous liquid crystalline interface.</a> Biomacromolecules. 17 (6), 2096-2103 (2016).</li><li>De Gennes, P. G., Prost, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The physics of liquid crystals. , (1993).</li><li>De Gennes, P. G., Brochard-Wyart, F., Quere, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Capillarity and wetting phenomena: drops, bubbles, pearls, waves. , (2003).</li><li>Okajima, M. K., Kaneko, D., Mitsumata, T., Kaneko, T., Watanabe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyanobacteria+that+produce+megamolecules+with+efficient+self-orientations.">Cyanobacteria that produce megamolecules with efficient self-orientations.</a> Macromolecules. 42 (8), 3058-3062 (2009).</li><li>Okeyoshi, K., Kawamura, R., Yoshida, R., Osada, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermo-+and+photo-enhanced+microtubule+formation+from+Ru(bpy)32+-conjugated+tubulin.">Thermo- and photo-enhanced microtubule formation from Ru(bpy)32+-conjugated tubulin.</a> J. Mater. Chem. B. 2, 41-45 (2014).</li><li>Matsuo, E. S., Tanaka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+discontinuous+volume-phase+transition+of+gels.">Kinetics of discontinuous volume-phase transition of gels.</a> J. Chem. Phys. 89, 1695-1703 (1988).</li><li>Okajima, K., Mishima, R., Amornwachirabodee, K., Mitsumata, T., Okeyoshi, K., Kaneko, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anisotropic+swelling+in+hydrogels+formed+by+cooperatively+aligned+megamolecules.">Anisotropic swelling in hydrogels formed by cooperatively aligned megamolecules.</a> RSC Adv. 5, 86723-86729 (2015).</li><li>Joshi, G., Okeyoshi, K., Okajima, M. K., Kaneko, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directional+control+of+diffusion+and+swelling+in+megamolecular+polysaccharide+hydrogels.">Directional control of diffusion and swelling in megamolecular polysaccharide hydrogels.</a> Soft Matter. 12, 5515-5518 (2016).</li></ol>

作者什么都没有透露。

有时很难为摄像机聚焦在样品上，由于透射光强度太低。在这种情况下，将延长的透明塑料薄膜上的阶段帮助安排的焦点。可观察到的分辨率的限制是依赖于摄像机镜头上，〜10微米在这种情况下。样品厚度，ΔY，的可观察的限制是依赖于该灯的最大光强度，〜在这种情况下10mm以下。 在图1B所示的装置的优点是，它允许侧视图样品的照片，以在干燥过程中作出。观察可以不依靠在水平平面上，这是在典型的显微镜中使用来进行。通过干燥实验期间站在单侧开孔，蒸发方向被限制，在重力的相反方向。监测侧视图还使干燥的大鼠的计算E 4。 在未来，通过将温度和湿度调节器在所述装置的样品台上，将有可能自动地监视在向秩序参数随时间的变化。此外，在建立一个平衡监测体重变化，将有助于浓度的估计。此方法也可用于澄清各向异性溶胀过程的多糖水凝胶11，12。因此，将可能监视软致动器的结构变化。

通过聚焦于生物聚合物的刚性，棒状的结构，动态软材料已被用于各种应用，包括多糖生物膜基质1中，"活性凝胶"细胞骨架蛋白2构成，并且所希望的形状3的"DNA折纸"。为了阐明的结构特性，许多策略已探索，如透射电子显微镜，扫描电子显微镜，原子力显微镜，和共聚焦荧光显微镜。然而，因为这些方法都处于干燥状态或静止状态进行的大部分，这是很难解释的动态行为在宏观尺度，在实际生活系统看到。最近，我们成功地通过偏振光4中观察到的水气-LC界面上的生物聚合物的动态行为。在取向的结构的可视化，同时干燥该生物聚合物解决方案，随时间的变化表明不稳定的空气-LC接口上的生物聚合物的自我整合。 在这里，我们描述了用于LC的生物聚合物溶液在使用偏振仪器空气-LC界面处的干燥的协议。而不是在LC相的其他分析不考虑干燥5， 图6，在干燥过程中的LC动力学通过在一个单侧开放单元评价在流体相中的侧视图的取向顺序参数这里调查。单元蒸发的组合和使用允许以受控的蒸发方向宏观监测偏振仪器。此外，有可能通过集中在吸附微区，将其受分子量，浓度等的晶体结构为了证明该方法的有效性来验证干燥记录，干燥亲与刚性杆形状基本生物聚合物，如多糖，微管（MTS），和DNA的正如事实，进行了调查。我们选择这些生物聚合物，因为它们与megamolecular权重分级大分子的典型例子，它们的分子间相互作用使他们能够形成LC状态。

<table border="0" cellpadding="0" cellspacing="0" width="617">
	<tbody>
		<tr height="69">
			<td height="69" style="height:69px;width:172px;">sacran</td>
			<td style="width:151px;">Green Science Materials Inc., Japan</td>
			<td style="width:131px;"></td>
			<td style="width:163px;">From Aphanothece sacrum. 
			Mw = 1.9 &#215; 107 g mol-1</td>
		</tr>
		<tr height="69">
			<td height="69" style="height:69px;width:172px;">xanthan gum</td>
			<td style="width:151px;">Taiyo Kagaku Co., Japan</td>
			<td style="width:131px;">Neosoft XC</td>
			<td style="width:163px;">From Xanthomonas campestris. 
			Mw = 4.7 &#215; 106 g mol-1</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">tubulin</td>
			<td style="width:151px;">Cytoskeleton, Inc., USA</td>
			<td style="width:131px;">T240</td>
			<td style="width:163px;">From porcine brain.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">GpCpp</td>
			<td style="width:151px;">Jena Bioscience, Germany</td>
			<td style="width:131px;">NU405L</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">piperazine-N,N&#8242;-bis(2-ethanesulfonic acid)</td>
			<td style="width:151px;">Sigma-Aldrichi, Co. LLC.</td>
			<td style="width:131px;">P6757-500G</td>
			<td style="width:163px;">PIPES</td>
		</tr>
		<tr height="85">
			<td height="85" style="height:85px;width:172px;">ethylene glycol-bis(&#946;-aminoethyl ether)-N,N,N&#39;,N&#39;-tetraacetic acid</td>
			<td style="width:151px;">Dojindo Molecular Technologies, Inc.</td>
			<td style="width:131px;">342-01314</td>
			<td style="width:163px;">EGTA</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">MgCl2-6H2O</td>
			<td style="width:151px;">Wako Pure Chemical Industries, Ltd.</td>
			<td style="width:131px;">135-15055</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">KOH</td>
			<td style="width:151px;">Wako Pure Chemical Industries, Ltd.</td>
			<td style="width:131px;">162-21813</td>
			<td style="width:163px;">pellet</td>
		</tr>
		<tr height="21">
			<td height="58" style="height:58px;width:172px;">DNA</td>
			<td rowspan="2" style="width:151px;">Sigma-Aldrich, Co. LLC.</td>
			<td rowspan="2" style="width:131px;">D1626</td>
			<td rowspan="2" style="width:163px;">From salmon testes. 
			Mw = 1.3 &#215; 106 Da (~2000 bp)</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">Tris-EDTA buffer solution</td>
			<td style="width:151px;">Sigma-Aldrich, Co. LLC.</td>
			<td style="width:131px;">T9285-100ML</td>
			<td style="width:163px;">10 mM Tris, pH 8.0, with 1 mM EDTA</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">slide glass</td>
			<td style="width:151px;">Matsunami Glass Ind., Ltd., Japan</td>
			<td style="width:131px;">S1111</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">silicon rubber sheet</td>
			<td style="width:151px;">Asone Co.</td>
			<td style="width:131px;">6-611-32</td>
			<td style="width:163px;">Thickness: 1 mm</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">centrifuge</td>
			<td style="width:151px;">Beckman-Coulter, Inc., USA</td>
			<td style="width:131px;">Avanti J-25</td>
			<td style="width:163px;">equipped with a JA-20 rotor</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">light source</td>
			<td style="width:151px;">Sumita Optical Glass, Inc., Japan</td>
			<td style="width:131px;">LS-LHA</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">light guide</td>
			<td style="width:151px;">Sumita Optical Glass, Inc., Japan</td>
			<td style="width:131px;">GF7.2-1-L1500R-M80 (AAAR-015M)</td>
			<td style="width:163px;">80 mm &#215; 80 mm</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">halogen lamp</td>
			<td style="width:151px;">Ushio Inc., Japan</td>
			<td style="width:131px;">JCR 15V150WBN</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">polarizer</td>
			<td style="width:151px;">Luceo, Co.,Ltd.</td>
			<td style="width:131px;">POLAX-42S</td>
			<td style="width:163px;">40 x 80 x 2t (45&#730;)</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">KMH-80</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">sample stage</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">TARW-25503L</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">sample holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">SHA-25RO</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">rod</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">ROU-12-40</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">posts holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">RS-6-40</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">posts holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">RS-12-60</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">posts holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">RS-12-80</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">posts holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">RS-12-130</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">carrier</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">CAA-25LS</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">camera holder</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">CMH-2</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">medium optical rail</td>
			<td style="width:151px;">Sigmakoki, Co.,Ltd.</td>
			<td style="width:131px;">OBA-500SH</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">lenstube</td>
			<td style="width:151px;">Tomytech, BORG</td>
			<td style="width:131px;">lenstube BK</td>
			<td style="width:163px;">80&#966;, L25 mm&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">lenstube</td>
			<td style="width:151px;">Tomytech, BORG</td>
			<td style="width:131px;">lenstube BK</td>
			<td style="width:163px;">80&#966;, L50 mm&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">multiband</td>
			<td style="width:151px;">Tomytech, BORG</td>
			<td style="width:131px;"></td>
			<td style="width:163px;">80&#966;&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">V plate</td>
			<td style="width:151px;">Tomytech, BORG</td>
			<td style="width:131px;">V plate 60S</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">plate holder</td>
			<td style="width:151px;">Viexen, Co.,Ltd.</td>
			<td style="width:131px;">plate holder SX</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">EOS Kiss X7i&#160;</td>
			<td style="width:151px;">Canon Inc., Japan</td>
			<td style="width:131px;">8594B001</td>
			<td style="width:163px;">with a standard zoom lens,&#160; EFP 18-55 mm</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">photographic software</td>
			<td style="width:151px;">Canon Inc., Japan</td>
			<td style="width:131px;">EOS Utility</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">PC</td>
			<td style="width:151px;">Microsoft</td>
			<td style="width:131px;">Surface</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">polarization microscope</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:131px;">BX51</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">first order retardation plate</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:131px;">U-TP530</td>
			<td style="width:163px;">&#955; = 530 nm</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">CCD camera</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:131px;">DP80</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:172px;">photographic software</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:131px;">cellSens Standard</td>
			<td style="width:163px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:172px;">Java-based image processing program</td>
			<td style="width:151px;">the National Institutes of Health</td>
			<td style="width:131px;">ImageJ</td>
			<td style="width:163px;"></td>
		</tr>
	</tbody>
</table>

methods for the self-integration of megamolecular biopolymers on the drying air-lc interface

使用水生物体总是容易在环境干燥。他们的活动具有基于生物聚合物 - 微观和宏观结构驱动，如在维管束移动水和皮肤保湿层的水的情况下看到。在这项研究中，我们开发了用于评估在干燥的生物聚合物组成的水性液晶（LC）的解决方案的效果的方法。由于LC生物聚合物具有megamolecular重，我们选择了研究多糖，细胞骨架蛋白和DNA。生物聚合物溶液的下偏振光干燥时的观测揭示milliscale自我整合从不稳定的空气-LC界面开始。水性LC生物聚合物溶液的动力学可以通过从单侧开孔蒸发水进行监测。通过分析使用交叉偏振光拍摄的图像，可以识别在取向秩序参数时空变化。这个方法可以不仅人工材料的各个领域，也自然的活组织的特性是有用的。我们相信，它将为软质材料在生物医学和环境领域提供的评价方法。

<html>使用该装置， 如图1中 ，从微区的自我整合到宏畴上的干燥空气-LC接口进行了评价（ 图2A）。作为干燥实验的第一示范，二种megamolecular多糖，SACRAN（M W = 1.9×107 克摩尔-1）和黄原胶（4.7×106 克摩尔-1）的，进行了比较。 图2B示出了在小区中的解决方案下的交叉偏振光的照片。干燥之前，它是可能观察到与透射光几个明亮区域的分散状态这两种解决方案。在60℃下干燥6个小时后，在溶液SACRAN空气-LC界面下方的区域成为高显著。这意味着，在结构域的凝胶收缩过程形成在界面宏观定向结构，类似于皮肤层形成"外部参照"&gt; 10。在另一方面，黄原胶溶液的强度，当温度刚从25℃增加至60℃，观察到的界面之下的一些小macrodomains急剧下降。这是因为黄原胶微区的流动性更为敏感温度比SACRAN微区的。界面上的取向的临界差异从而通过使用偏振装置检测。 图2C和Movie S1示出了用于在SACRAN溶液的干燥过程中空间-时间分析的结果。透射光强度指示中，微区的取向顺序参数。周围的空气 - 液体界面的峰强度显著增加，并且厚度生长至〜2毫米。这些结果清楚地表明，微区启动定向从空中-LC接口的ð长成平行于该界面的milliscale域。从下偏振光这种观察，因此可以以可视化的流体运动中的干燥过程。 在宏畴尺寸和取向方向而言SACRAN和黄原胶之间的差异也通过用一阶延迟板（ 图2D）的偏光显微镜证实。该SACRAN流体相显示一个蓝色区域，这意味着形成在界面处的单个宏畴。与此相反，黄原胶流体相呈蓝色，黄色和粉红色的区域，这意味着与任意方向形成多个macrodomains。 该方法还探讨用于与megamolecular权重，比较了三种类型的基本刚性的生物聚合物的-多糖（SACRAN:M W = 1.9×107 克摩尔-1，微区长度&gt; 20微米），的MT（M W = 10 9 -1010克摩尔-1，微区长度&gt; 10微米），和DNA（M W = 1.3×106 克摩尔-1，微区长度&lt;1微米） -在37℃的生理环境。如在图3B中所示的干燥之前，SACRAN溶液和MT溶液显示出相似的LC状态，其中在整个区域散射结构域。在干燥过程中，在MT溶液中的结构域也经历自我整合从空气-LC接口，和散射结构域集成到单个宏畴。在另一方面，该DNA溶液显示在液相中没有特定取向。在MT溶液，并用缓冲液中制备的DNA溶液的情况下，需要注意的是集成是通过在干燥过程中变化，盐浓度，pH和离子强度的影响是重要的。 图3C）。所述SACRAN干燥记录显示出因为milliscale单个宏畴形成的显著双折射强度。用于MT干燥记录，我们观察到波状束，其中长轴平行于X轴。与此相反，DNA溶液的干燥记录显示晶粒形状macrodomains &lt;5微米的直径和在任意方向。从这些观察，很清楚的是，宏畴尺寸由棒状微区的长度的影响。这是因此，可以通过使用偏振显微镜观察干燥记录来评估生物聚合物微区的方向取向。 总之，使用使用偏振光的方法对干燥空气-LC接口megamolecular生物聚合物的自我整合。水性LC溶液的动力学是由从一侧开细胞蒸发水监测。通过分析使用交叉偏振光拍摄的图像，它是能够识别时空变化和取向有序参数。考虑到表现出干燥过程类似于自然过程，这种方法将是不仅人工材料在各种领域中的表征是有用的，但也自然生活组织。我们认为，这可能为软质材料在生物医学和环境领域提供的评价方法。 <img alt="图1" src="/files/ftp_upload/55274/55274fig1.jpg" /> 图1:干燥实验。 （A）在一侧开孔的解决方案的示意图。 （B）下交叉偏振光用于观测实验装置的示意图。偏振片通常被调整为45°和135°。 （C） 实际的设备。该图已被从参照图6进行修改。版权所有:美国化学学会，2016年<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55274/55274fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/55274/55274fig2.jpg" /> 图2:多糖SACRAN和黄原胶的水溶液的干燥过程。 （A） 干燥空气-LC接口上的自我整合的示意图。 （B） 在初始状态后2种多糖溶液的侧视图在60℃下交偏振光干燥6个小时。初始聚合物浓度为0.5重量％。 （C） 通过正交尼科耳上用于在给定时间拍摄每个画面的Z方向的直线透射光强度。 （D） 在单元中的聚合物溶液在60℃下干燥6个小时后的偏光显微镜图像。红色箭头:在接口上macrodomains。该图已被从参照图6进行修改。版权所有:美国化学学会，2016年<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55274/55274fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/55274/55274fig3.jpg" /> 图3:生物聚合物的水溶液和干燥记录的干燥过程。 （A）的多边形的来源accharides（蓝藻）的MT（猪脑）和DNA（鲑鱼睾丸）。 （B） 在37℃下交偏振光干燥时SACRAN，MT，和DNA溶液的侧视图。初始聚合物浓度为0.5重量％。 （C） 通过正交尼科耳的给定方向上的玻璃基板上的干燥的聚合物膜的显微图像。所有比例尺是50微米。该图已被从参照图6进行修改。版权所有:美国化学学会，2016年<a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55274/55274fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="电影S1" src="/files/ftp_upload/55274/55274vid1.jpg" /> 电影S1:在60℃ 下 干燥时干燥所述SACRAN溶液的过程中 ，使用不良观察交叉尼科尔。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/55274/Movie_S1-3fps.avi" target="_blank">请点击这里下载这部电影。</a>

Watch this Scientific Journal Video about Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface at JoVE.com

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

在这里提供了一种用于生物聚合物megamolecular的空气 - 液体界面的结晶在干燥引起的自我整合方法。这种方法将是有益的，不仅对于理解生物聚合物的宏观潜力，同时也为软质材料在生物医学和环境领域的评价方法。

对干燥空气-LC接口Megamolecular生物大分子的自我整合方法

Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and ...

methods-for-self-integration-megamolecular-biopolymers-on-drying-air

Nanyang Technological University

Research

JoVE Journal

Bioengineering

6.0K 次观看.  Japan Advanced Institute of Science and Technology. 在这里提供了一种用于生物聚合物megamolecular的空气 - 液体界面的结晶在干燥引起的自我整合方法。这种方法将是有益的，不仅对于理解生物聚合物的宏观潜力，同时也为软质材料在生物医学和环境领域的评价方法。 

视频: Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

Bridging the Bio-Electronic Interface with Biofabrication

Advancements in lab-on-a-chip technology promise to revolutionize both research and medicine through lower costs, better sensitivity, portability, and higher throughput. The incorporation of biological components onto biological microelectromechanical systems (bioMEMS) has shown great potential for achieving these goals. Microfabricated electronic chips allow for micrometer-scale features as well as an electrical connection for sensing and actuation. Functional biological components give the system the capacity for specific detection of analytes, enzymatic functions, and whole-cell capabilities. Standard microfabrication processes and bio-analytical techniques have been successfully utilized for decades in the computer and biological industries, respectively. Their combination and interfacing in a lab-on-a-chip environment, however, brings forth new challenges. There is a call for techniques that can build an interface between the electrode and biological component that is mild and is easy to fabricate and pattern.
Biofabrication, described here, is one such approach that has shown great promise for its easy-to-assemble incorporation of biological components with versatility in the on-chip functions that are enabled. Biofabrication uses biological materials and biological mechanisms (self-assembly, enzymatic assembly) for bottom-up hierarchical assembly. While our labs have demonstrated these concepts in many formats 1,2,3, here we demonstrate the assembly process based on electrodeposition followed by multiple applications of signal-based interactions. The assembly process consists of the electrodeposition of biocompatible stimuli-responsive polymer films on electrodes and their subsequent functionalization with biological components such as DNA, enzymes, or live cells 4,5. Electrodeposition takes advantage of the pH gradient created at the surface of a biased electrode from the electrolysis of water 6,7,. Chitosan and alginate are stimuli-responsive biological polymers that can be triggered to self-assemble into hydrogel films in response to imposed electrical signals 8. The thickness of these hydrogels is determined by the extent to which the pH gradient extends from the electrode. This can be modified using varying current densities and deposition times 6,7. This protocol will describe how chitosan films are deposited and functionalized by covalently attaching biological components to the abundant primary amine groups present on the film through either enzymatic or electrochemical methods 9,10. Alginate films and their entrapment of live cells will also be addressed 11. Finally, the utility of biofabrication is demonstrated through examples of signal-based interaction, including chemical-to-electrical, cell-to-cell, and also enzyme-to-cell signal transmission. 
Both the electrodeposition and functionalization can be performed under near-physiological conditions without the need for reagents and thus spare labile biological components from harsh conditions. Additionally, both chitosan and alginate have long been used for biologically-relevant purposes 12,13. Overall, biofabrication, a rapid technique that can be simply performed on a benchtop, can be used for creating micron scale patterns of functional biological components on electrodes and can be used for a variety of lab-on-a-chip applications.

This article describes a biofabrication approach: deposition of stimuli-responsive polysaccharides in the presence of biased electrodes to create biocompatible films which can be functionalized with cells or proteins. We demonstrate a bench-top strategy for the generation of the films as well as their basic uses for creating interactive biofunctionalized surfaces for lab-on-a-chip applications.

生物电子界面衔接与Biofabrication

Advancements in lab-on-a-chip technology promise to revolutionize both research and medicine through lower costs, better sensitivity, portability, and ...

科研

生物工程

Flexural Rigidity Measurements of Biopolymers Using Gliding Assays

Microtubules are cytoskeletal polymers which play a role in cell division, cell mechanics, and intracellular transport. Each of these functions requires microtubules that are stiff and straight enough to span a significant fraction of the cell diameter. As a result, the microtubule persistence length, a measure of stiffness, has been actively studied for the past two decades1. Nonetheless, open questions remain: short microtubules are 10-50 times less stiff than long microtubules2-4, and even long microtubules have measured persistence lengths which vary by an order of magnitude5-9.
	Here, we present a method to measure microtubule persistence length. The method is based on a kinesin-driven microtubule gliding assay10. By combining sparse fluorescent labeling of individual microtubules with single particle tracking of individual fluorophores attached to the microtubule, the gliding trajectories of single microtubules are tracked with nanometer-level precision. The persistence length of the trajectories is the same as the persistence length of the microtubule under the conditions used11. An automated tracking routine is used to create microtubule trajectories from fluorophores attached to individual microtubules, and the persistence length of this trajectory is calculated using routines written in IDL.
	This technique is rapidly implementable, and capable of measuring the persistence length of 100 microtubules in one day of experimentation. The method can be extended to measure persistence length under a variety of conditions, including persistence length as a function of length along microtubules. Moreover, the analysis routines used can be extended to myosin-based acting gliding assays, to measure the persistence length of actin filaments as well.

A method to measure the persistence length or flexural rigidity of biopolymers is described. The method uses a kinesin-driven microtubule gliding assay to experimentally determine the persistence length of individual microtubules and is adaptable to actin-based gliding assays.

使用滑翔分析生物大分子的抗弯刚度测量

Microtubules are cytoskeletal polymers which  play a role in cell division, cell mechanics, and intracellular transport. Each of these functions requires ...

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

在光刻技术定义的聚对二甲苯-C细胞图案:二氧化硅<sub&gt; 2</sub&gt;基板

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

Molecular Entanglement and Electrospinnability of Biopolymers

Electrospinning is a fascinating technique to fabricate micro- to nano-scale fibers from a wide variety of materials. For biopolymers, molecular entanglement of the constituent polymers in the spinning dope was found to be an essential prerequisite for successful electrospinning. Rheology is a powerful tool to probe the molecular conformation and interaction of biopolymers. In this report, we demonstrate the protocol for utilizing rheology to evaluate the electrospinnability of two biopolymers, starch and pullulan, from their dimethyl sulfoxide (DMSO)/water dispersions. Well-formed starch and pullulan fibers with average diameters in the submicron to micron range were obtained. Electrospinnability was evaluated by visual and microscopic observation of the fibers formed. By correlating the rheological properties of the dispersions to their electrospinnability, we demonstrate that molecular conformation, molecular entanglement, and shear viscosity all affect electrospinning. Rheology is not only useful in solvent system selection and process optimization, but also in understanding the mechanism of fiber formation on a molecular level.

Electrospinning is a fascinating technique used to fabricate micro- to nano-scale fibers from a wide variety of materials. Molecular entanglement of the constituent polymers in the spinning dope is essential for successful electrospinning. We present a protocol for utilizing rheology to evaluate the electrospinnability of two biopolymers, starch and pullulan.

分子纠缠与生物大分子的Electrospinnability

Electrospinning is a fascinating technique to fabricate micro- to nano-scale fibers from a wide variety of materials. For biopolymers, molecular ...

Gene Transfection toward Spheroid Cells on Micropatterned Culture Plates for Genetically-modified Cell Transplantation

To improve the therapeutic effectiveness of cell transplantation, a transplantation system of genetically modified, injectable spheroids was developed. The cell spheroids are prepared in a culture system on micropatterned plates coated with a thermosensitive polymer. A number of spheroids are formed on the plates, corresponding to the cell adhesion areas of 100 &#181;m diameter that are regularly arrayed in a two-dimensional manner, surrounded by non-adhesive areas that are coated by a polyethylene glycol (PEG) matrix. The spheroids can be easily recovered as a liquid suspension by lowering the temperature of the plates, and their structure is well maintained by passing them through injection needles with a sufficiently large caliber (over 27 G). Genetic modification is achieved by gene transfection using the original non-viral gene carrier, polyplex nanomicelle, which is capable of introducing genes into cells without disrupting the spheroid structure. For primary hepatocyte spheroids transfected with a luciferase-expressing gene, the luciferase is sustainably obtained in transplanted animals, along with preserved hepatocyte function, as indicated by albumin expression. This system can be applied to a variety of cell types including mesenchymal stem cells.

This protocol describes a cell transplantation system using genetically modified, injectable spheroids. Cell spheroids are cultured on micropatterned culture plates and recovered after gene introduction using polyplex nanomicelles. This system facilitates prolonged transgene expression from the transplanted cells in host animals while maintaining the innate function of the cells.

基因转染向着文化微模式球体板细胞基因修饰的细胞移植

To improve the therapeutic effectiveness of cell transplantation, a transplantation system of genetically modified, injectable spheroids was developed. ...

Methods for Characterizing the Co-development of Biofilm and Habitat Heterogeneity

Biofilms are surface-attached microbial communities that have complex structures and produce significant spatial heterogeneities. Biofilm development is strongly regulated by the surrounding flow and nutritional environment. Biofilm growth also increases the heterogeneity of the local microenvironment by generating complex flow fields and solute transport patterns. To investigate the development of heterogeneity in biofilms and interactions between biofilms and their local micro-habitat, we grew mono-species biofilms of Pseudomonas aeruginosa and dual-species biofilms of P. aeruginosa and Escherichia coli under nutritional gradients in a microfluidic flow cell. We provide detailed protocols for creating nutrient gradients within the flow cell and for growing and visualizing biofilm development under these conditions. We also present protocols for a series of optical methods to quantify spatial patterns in biofilm structure, flow distributions over biofilms, and mass transport around and within biofilm colonies. These methods support comprehensive investigations of the co-development of biofilm and habitat heterogeneity.

Biofilms have complex interactions with their surrounding environment. To comprehensively investigate biofilm-environment interactions, we present here a series of methods to create heterogeneous chemical environment for biofilm development, to quantify local flow velocity, and to analyze mass transport in and around biofilm colonies.

方法表征的共同发展生物膜和生境异质性

Biofilms are surface-attached microbial communities that have complex structures and produce significant spatial heterogeneities. Biofilm development is ...

PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions

Numerous cellular proteins interact with membrane surfaces to affect essential cellular processes. These interactions can be directed towards a specific lipid component within a membrane, as in the case of phosphoinositides (PIPs), to ensure specific subcellular localization and/or activation. PIPs and cellular PIP-binding domains have been studied extensively to better understand their role in cellular physiology. We applied a pH modulation assay on supported lipid bilayers (SLBs) as a tool to study protein-PIP interactions. In these studies, pH sensitive ortho-Sulforhodamine B conjugated phosphatidylethanolamine is used to detect protein-PIP interactions. Upon binding of a protein to a PIP-containing membrane surface, the interfacial potential is modulated (i.e. change in local pH), shifting the protonation state of the probe. A case study of the successful usage of the pH modulation assay is presented by using phospholipase C delta1 Pleckstrin Homology (PLC-&#948;1 PH) domain and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) interaction as an example. The apparent dissociation constant (Kd,app) for this interaction was 0.39 &#177; 0.05 &#181;M, similar to Kd,app values obtained by others. As previously observed, the PLC-&#948;1 PH domain is PI(4,5)P2 specific, shows weaker binding towards phosphatidylinositol 4-phosphate, and no binding to pure phosphatidylcholine SLBs. The PIP-on-a-chip assay is advantageous over traditional PIP-binding assays, including but not limited to low sample volume and no ligand/receptor labeling requirements, the ability to test high- and low-affinity membrane interactions with both small and large molecules, and improved signal to noise ratio. Accordingly, the usage of the PIP-on-a-chip approach will facilitate the elucidation of mechanisms of a wide range of membrane interactions. Furthermore, this method could potentially be used in identifying therapeutics that modulate protein&#39;s capacity to interact with membranes.

Here we present a supported lipid bilayer in the context of a microfluidic platform to study protein-phosphoinositide interactions using a label-free method based on pH modulation.

PIP-on-a-chip:蛋白质 - 磷酸肌醇相互作用的无标记研究

Numerous cellular proteins interact with membrane surfaces to affect essential cellular processes. These interactions can be directed towards a specific ...

Microhoneycomb Monoliths Prepared by the Unidirectional Freeze-drying of Cellulose Nanofiber Based Sols: Method and Extensions

Monolithic honeycomb structures have been attractive to multidisciplinary fields due to their high strength-to-weight ratio. Particularly, microhoneycomb monoliths (MHMs) with micrometer-scale channels are expected as efficient platforms for reactions and separations because of their large surface areas. Up to now, MHMs have been prepared by a unidirectional freeze-drying (UDF) method only from very limited precursors. Herein, we report a protocol from which a series of MHMs consisting of different components can be obtained. Recently, we found that cellulose nanofibers function as a distinct structure-directing agent towards the formation of MHMs through the UDF process. By mixing the cellulose nanofibers with water soluble substances which do not yield MHMs, a variety of composite MHMs can be prepared. This significantly enriches the chemical constitution of MHMs towards versatile applications.

Here, we present a general protocol to prepare a variety of microhoneycomb monoliths (MHMs) in which fluid can pass through with an extremely low pressure drop. MHMs obtained are expected to be used as filters, catalyst supports, flow-type electrodes, sensors and scaffolds for biomaterials.

纤维素碳纤维溶胶单向冷冻干燥制备 Microhoneycomb 石柱: 方法和外延

Monolithic honeycomb structures have been attractive to multidisciplinary fields due to their high strength-to-weight ratio. Particularly, microhoneycomb ...

Fabrication of the Composite Regenerative Peripheral Nerve Interface (C-RPNI) in the Adult Rat

Recent advances in neuroprosthetics have enabled those living with extremity loss to reproduce many functions native to the absent extremity, and this is often accomplished through integration with the peripheral nervous system. Unfortunately, methods currently employed are often associated with significant tissue damage which prevents prolonged use. Additionally, these devices often lack any meaningful degree of sensory feedback as their complex construction dampens any vibrations or other sensations a user may have previously depended on when using more simple prosthetics. The composite regenerative peripheral nerve interface (C-RPNI) was developed as a stable, biologic construct with the ability to amplify efferent motor nerve signals while providing simultaneous afferent sensory feedback. The C-RPNI consists of a segment of free dermal and muscle graft secured around a target mixed sensorimotor nerve, with preferential motor nerve reinnervation of the muscle graft and sensory nerve reinnervation of the dermal graft. In rats, this construct has demonstrated the generation of compound muscle action potentials (CMAPs), amplifying the target nerve&#39;s signal from the micro- to milli-volt level, with signal to noise ratios averaging approximately 30-50. Stimulation of the dermal component of the construct generates compound sensory nerve action potentials (CSNAPs) at the proximal nerve. As such, this construct has promising future utility towards the realization of the ideal, intuitive prosthetic.

Fabrication of the Composite Regenerative Peripheral Nerve Interface C-RPNI in the Adult Rat

The following manuscript describes a novel method for developing a biologic, closed loop neural feedback system termed the composite regenerative peripheral nerve interface (C-RPNI). This construct has the ability to integrate with peripheral nerves to amplify efferent motor signals while simultaneously providing afferent sensory feedback.

成年大鼠复合再生外周神经接口（C-RPNI）的制造

Recent advances in neuroprosthetics have enabled those living with extremity loss to reproduce many functions native to the absent extremity, and this is ...

Silicon Nanowires and Optical Stimulation for Investigations of Intra- and Intercellular Electrical Coupling

Myofibroblasts can spontaneously internalize silicon nanowires (SiNWs), making them an attractive target for bioelectronic applications. These cell-silicon hybrids offer leadless optical modulation capabilities with minimal perturbation to normal cell behavior. The optical capabilities are obtained by the photothermal and photoelectric properties of SiNWs. These hybrids can be harvested using standard tissue culture techniques and then applied to different biological scenarios. We demonstrate here how these hybrids can be used to study the electrical coupling of cardiac cells and compare how myofibroblasts couple to one another or to cardiomyocytes. This process can be accomplished without special equipment beyond a fluorescent microscope with coupled laser line. Also shown is the use of a custom-built MATLAB routine that allows the quantification of calcium propagation within and between the different cells in the culture. Myofibroblasts are shown to have a slower electrical response than that of cardiomyocytes. Moreover, the myofibroblast intercellular propagation shows slightly slower, though comparable velocities to their intracellular velocities, suggesting passive propagation through gap junctions or nanotubes. This technique is highly adaptable and can be easily applied to other cellular arenas, for in vitro as well as in vivo or ex vivo investigations.

This protocol describes the use of silicon nanowires for intracellular optical bio-modulation of cell in a simple and easy to perform method. The technique is highly adaptable to diverse cell types and can be used for in vitro as well as in vivo applications.