Name: obtention of giant unilamellar hybrid vesicles by electroformation and measurement of their mechanical properties by micropipette aspiration
Uploaded: 2020-01-19T13:00:00
Description: Watch this Scientific Journal Video about Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration at JoVE.com

作者感谢ANR的财政支持（ANR Sysa）。

1. 制造微移液器
注：此处，内径为 6 至 12 μm 且直径长约 3-4 mm 的微移液器是必需的。下面介绍了制造微移液的详细方法。
<ol><li>将硼硅酸盐玻璃毛细管放在拉拔器的拉杆中，通过拧紧旋钮来固定其中一个端部。</li>
	<li>小心地将玻璃滑过加热器室侧面的孔。</li>
	<li>拧紧另一端的夹紧旋钮。</li>
	<li>控制尖端的大小和片长，以达到所需的规格。为此，优化加热温度、拉力、?...

<ol>
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F., Schatz, C., Lecommandoux, S., Sandre, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+polymer/lipid+vesicles:+state+of+the+art+and+future+perspectives.">Hybrid polymer/lipid vesicles: state of the art and future perspectives.</a> Materials Today. 16 (10), 397-402 (2013).</li><li>Schulz, M., Binder, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mixed+Hybrid+Lipid/Polymer+Vesicles+as+a+Novel+Membrane+Platform.">Mixed Hybrid Lipid/Polymer Vesicles as a Novel Membrane Platform.</a> Macromolecular Rapid Communications. 36, 2031-2041 (2015).</li><li>Schneider, M. B., Jenkins, J. T., Webb, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+fluctuations+of+large+quasi-spherical+bimolecular+phospholipid+vesicles.">Thermal fluctuations of large quasi-spherical bimolecular phospholipid vesicles.</a> Journal De Physique. 45 (9), 1457-1472 (1984).</li><li>Dimova, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+developments+in+the+field+of+bending+rigidity+measurements+on+membranes.">Recent developments in the field of bending rigidity measurements on membranes.</a> Advances in Colloid and Interface Science. 208, 225-234 (2014).</li><li>Rodr&#237;guez-Garc&#237;a, 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=Polymersomes:+smart+vesicles+of+tunable+rigidity+and+permeability.">Polymersomes: smart vesicles of tunable rigidity and permeability.</a> Soft Matter. 7 (4), 1532-1542 (2011).</li><li>Angelova, M. I., Dimitrov, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liposome+electroformation.">Liposome electroformation.</a> Faraday Discussions of the Chemical Society. 81, 303-311 (1986).</li><li>Dao, T. P. T., 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=Membrane+properties+of+giant+polymer+and+lipid+vesicles+obtained+by+electroformation+and+pva+gel-assisted+hydration+methods.">Membrane properties of giant polymer and lipid vesicles obtained by electroformation and pva gel-assisted hydration methods.</a> Colloids and Surfaces A: Physicochemical and Engineering Aspects. 533, 347-353 (2017).</li><li>Pereno, V., 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=Electroformation+of+Giant+Unilamellar+Vesicles+on+Stainless+Steel+Electrodes.">Electroformation of Giant Unilamellar Vesicles on Stainless Steel Electrodes.</a> ACS omega. 2 (3), 994-1002 (2017).</li><li>Evans, E., Rawicz, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entropy-driven+tension+and+bending+elasticity+in+condensed-fluid+membranes.">Entropy-driven tension and bending elasticity in condensed-fluid membranes.</a> Physical Review Letters. 64 (17), 2094-2097 (1990).</li><li>Dao, T. P. T., 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=Modulation+of+phase+separation+at+the+micron+scale+and+nanoscale+in+giant+polymer/lipid+hybrid+unilamellar+vesicles+(GHUVs).">Modulation of phase separation at the micron scale and nanoscale in giant polymer/lipid hybrid unilamellar vesicles (GHUVs).</a> Soft Matter. 13 (3), 627-637 (2017).</li><li>Helfrich, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elastic+properties+of+lipid+bilayers:+theory+and+possible+experiments.">Elastic properties of lipid bilayers: theory and possible experiments.</a> Z Naturforsch C. 11 (11), 693-703 (1973).</li><li>Dao, T. P. T., 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=The+combination+of+block+copolymers+and+phospholipids+to+form+giant+hybrid+unilamellar+vesicles+(GHUVs)+does+not+systematically+lead+to+&amp;#34;intermediate''+membrane+properties.">The combination of block copolymers and phospholipids to form giant hybrid unilamellar vesicles (GHUVs) does not systematically lead to &amp;#34;intermediate'' membrane properties.</a> Soft Matter. 14 (31), 6476-6484 (2018).</li><li>Shoemaker, S. D., Kyle Vanderlick, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Material+Studies+of+Lipid+Vesicles+in+the+L&#945;+and+L&#945;-Gel+Coexistence+Regimes.">Material Studies of Lipid Vesicles in the L&#945; and L&#945;-Gel Coexistence Regimes.</a> Biophysical Journal. 84 (2), 998-1009 (2003).</li><li>Longo, M. L., Ly, H. V., Dopico, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods in Membrane Lipids. , 421-437 (2007).</li><li>Chen, D., Santore, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+copolymer-phospholipid+vesicles:+phase+separation+resembling+mixed+phospholipid+lamellae,+but+with+mechanical+stability+and+control.">Hybrid copolymer-phospholipid vesicles: phase separation resembling mixed phospholipid lamellae, but with mechanical stability and control.</a> Soft Matter. 11 (13), 2617-2626 (2015).</li><li>Mabrouk, E., 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=Formation+and+material+properties+of+giant+liquid+crystal+polymersomes.">Formation and material properties of giant liquid crystal polymersomes.</a> Soft Matter. 5, 1870-1878 (2009).</li><li>Henriksen, J., 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=Universal+behavior+of+membranes+with+sterols.">Universal behavior of membranes with sterols.</a> Biophysical Journal. 90 (5), 1639-1649 (2006).</li><li>Ly, H. V., Block, D. E., Longo, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interfacial+Tension+Effect+of+Ethanol+on+Lipid+Bilayer+Rigidity,+Stability,+and+Area/Molecule:&#8201;+A+Micropipet+Aspiration+Approach.">Interfacial Tension Effect of Ethanol on Lipid Bilayer Rigidity, Stability, and Area/Molecule:&#8201; A Micropipet Aspiration Approach.</a> Langmuir. 18 (23), 8988-8995 (2002).</li><li>Bermudez, H., Hammer, D. A., Discher, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Bilayer+Thickness+on+Membrane+Bending+Rigidity.">Effect of Bilayer Thickness on Membrane Bending Rigidity.</a> Langmuir. 20, 540-543 (2004).</li></ol>

微移液器的涂层是获得可靠测量的关键点之一。必须防止囊泡粘附在微移液器上，在文献中通常使用涂层17、18、19、20、21与BSA、β-酪蛋白或西沙西尔。很少提及涂装程序的详细信息。
在搅拌下，BSA 的溶解应至少进行 4 小时，以实现良好的溶解。然而，?...

从磷脂（脂质体）获得的巨型囊泡自20世纪70年代以来被广泛用作基本细胞膜模型1。在20世纪90年代后期，从共聚物的自组装中获得的晶型形态，根据其脂质类比2，3，被命名为聚合物体，迅速成为具有弱机械稳定性和模块化化学功能的脂质体的有趣替代品。然而，与脂质体相比，它们的细胞生物体性质相当有限，因为脂质体由磷脂组成，磷脂是细胞膜的主要成分。此外，在药物输送等应用中，其低膜渗透性可能是一个问题，需要控制物种通过膜的扩散。最近，磷脂与块共聚物的关联，设计混合聚合物脂质囊泡和膜已成为越来越多的研究课题4，5。其主要思想是设计实体，将每种成分（脂质双层的生物功能和渗透性）与聚合物膜的机械稳定性和化学多功能性协同结合，这些优势可在不同的应用中加以利用：受控和靶向药物输送、用于诊断的生物传感器内的生物分子识别、人造细胞的功能膜、生物启发微/纳米反应器的开发。
如今，不同的科学界（生物化学家、化学家、生物物理学家、物理化学家、生物学家）对开发更先进的细胞膜模型越来越感兴趣。在这里，我们的目标是尽可能详细地提出现有方法（电镀、微移液吸入）来获得和表征巨型囊泡的机械特性，以及最近"先进"的细胞膜模型，即混合聚合物脂质巨型囊泡4、5。
这些方法的目的是获得可靠的测量面积的可压缩性和弯曲膜膜，以及其解压应力和应变。测量巨型囊泡弯曲刚度的最常见的技术之一是基于直接视频显微镜观察的波动分析6，7;但这需要较大的可见膜波动，并且不会在厚膜（如聚合物体）上系统地获得。区域可压缩模量可以用兰缪尔·布洛杰特技术进行实验确定，但最常见的是单层8。微移液器吸气技术允许在一个实验中测量形成巨型单体囊泡 （GUV） 的双层体上的两种莫杜利。
以下方法适用于所有两栖分子或大分子，能够形成双层，因此，通过电形成体囊。这需要在电形成温度下的双层结构具有流体特性。

<table>
	<tbody>
		<tr>
			<td>Required equipment and materials for micropipette design</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Borosilicate Glass Capillaries</td>
			<td>World Precision Instruments</td>
			<td>1B100-4</td>
			<td>external and internal diameter of 1mm and 0.58 mm respectively.</td>
		</tr>
		<tr>
			<td>Filament installed</td>
			<td>Sutter Instrument Co.</td>
			<td>FB255B</td>
			<td>2.5mm*2.5mm Box Filament</td>
		</tr>
		<tr>
			<td>Flaming/Brown Micropipette Puller</td>
			<td>Sutter Instrument Co.</td>
			<td>Model P-97</td>
			<td></td>
		</tr>
		<tr>
			<td>Microforge</td>
			<td>NARISHGE Co.</td>
			<td>MF-900</td>
			<td>fitted with two objectives (10x and 32x)</td>
		</tr>
		<tr>
			<td>Materials for coating pipette tips with BSA</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin Fraction V (BSA)</td>
			<td>Sigma-Aldrich</td>
			<td>10735078001</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 1 ml syringe Luer Tip</td>
			<td>Codan</td>
			<td>62.1612</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 10 ml syringe Luer Tip</td>
			<td>Codan</td>
			<td>626616</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 5 ml syringe Luer Tip</td>
			<td>Codan</td>
			<td>62.5607</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable acetate cellulose filter</td>
			<td>Cluzeau Info Labo</td>
			<td>L5003SPA</td>
			<td>Pore size: 0.22&#181;m, diameter: 25mm</td>
		</tr>
		<tr>
			<td>Flexible Fused Silica Capillary Tubing</td>
			<td>Polymicro Technologies.</td>
			<td>TSP530660</td>
			<td>Inner Diameter 536&#181;m, Outer Diameter 660&#181;m,</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sigma-Aldrich</td>
			<td>G5767</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe 500 &#181;L luer Lock GASTIGHT</td>
			<td>Hamilton Syringe Company</td>
			<td>1750</td>
			<td></td>
		</tr>
		<tr>
			<td>Test tube rotatory mixer</td>
			<td>Labinco</td>
			<td>28210109</td>
			<td></td>
		</tr>
		<tr>
			<td>Micromanipulation Set up</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum Optical Rail, 1000 mm Length, M4 threads, X48 Series</td>
			<td>Newport</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Damped Optical Table</td>
			<td>Newport</td>
			<td></td>
			<td>used as support of microscope to prevent external vibrations.</td>
		</tr>
		<tr>
			<td>Micromanipulator</td>
			<td>Eppendorf</td>
			<td>Patchman NP 2</td>
			<td>The module unit (motor unit for X, Y and Z movement) is mounted on the inverted microscope by the way of an adapter.</td>
		</tr>
		<tr>
			<td>Micrometer</td>
			<td>Mitutoyo Corporation</td>
			<td>350-354-10</td>
			<td>Digimatic LCD Micrometer Head 25,4 mm Range 0,001 mm</td>
		</tr>
		<tr>
			<td>Plexiglass water reservoir (100 ml)</td>
			<td>Home made</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>TCS SP5 inverted confocal microscope (DMI6000) equipped with a resonant scanner and a water immersion objective (HCX APO L 40x/0.80 WU-V-I).</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>X48 Rail Carrier 80 mm Length,with 1/4-20, 8-32 and 4-40 thread</td>
			<td>Newport</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Materials for sucrose and amphiphile solution preparation</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td><a href="https://www.sigmaaldrich.com/catalog/substance/2oleoyl1palmitoylsnglycero3phosphocholine760082685331611" target="_blank">2-Oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine</a></td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>VWR</td>
			<td>22711.244</td>
			<td></td>
		</tr>
		<tr>
			<td>L-&#945;-Phosphatidylethanolamine-N-(lissamine rhodamine B sulfonyl)</td>
			<td>Sigma-Aldrich</td>
			<td>810146C</td>
			<td>Rhodamine tagged lipid</td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Sigma-Aldrich</td>
			<td>S7903</td>
			<td></td>
		</tr>
		<tr>
			<td>Electroformation set up</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>10 &#181;L glass capillary ringcaps</td>
			<td>Hirschmann</td>
			<td>9600110</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable 1 ml syringe Luer Tip</td>
			<td>Codan</td>
			<td>62.1612</td>
			<td></td>
		</tr>
		<tr>
			<td>H Grease</td>
			<td>Apiezon</td>
			<td>Apiezon H Grease</td>
			<td>Silicon-free grease</td>
		</tr>
		<tr>
			<td>Indium tin oxide coated glass slides</td>
			<td>Sigma-Aldrich</td>
			<td>703184</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle</td>
			<td>Terumo</td>
			<td>AN2138R1</td>
			<td>0.8 x 38 mm</td>
		</tr>
		<tr>
			<td>Ohmmeter (Multimeter)</td>
			<td>Voltcraft</td>
			<td>VC140</td>
			<td></td>
		</tr>
		<tr>
			<td>Toluene</td>
			<td>VWR</td>
			<td>28676.297</td>
			<td></td>
		</tr>
		<tr>
			<td>Voltage generator</td>
			<td>Keysight</td>
			<td>33210A</td>
			<td></td>
		</tr>
	</tbody>
</table>

obtention of giant unilamellar hybrid vesicles by electroformation and measurement of their mechanical properties by micropipette aspiration

从磷脂和共聚物中获得的巨型囊泡可以在不同的应用中被利用：受控和靶向药物输送、用于诊断的生物传感器内的生物分子识别、人造细胞的功能膜以及生物启发微/纳米反应器的开发。在所有这些应用中，其膜特性的表征至关重要。在现有的表征技术中，由 E. Evans 开创的微移液器吸气允许测量膜的机械特性，如面积压缩模量、弯曲模量和解压应力和应变。在这里，我们介绍了从脂质或共聚物（或两者）的薄膜中获取巨型囊泡的所有方法和详细程序，微移液器的制造和表面处理，以及导致测量上述所有参数的吸气程序。

根据上述协议， 我们研究了不同的合成巨型单片杆菌囊泡（GUV），从磷脂获得：2-oleoyl-1-palmitoyl-sn-甘油-3磷胆碱（POPC），三聚物共聚物：聚（环氧）-b-聚宝（二甲基硅氧烷）-b-聚氨酯（环氧乙烷）（PEO12-b-PDMS43-b-PEO12）在先前的研究13中合成，以及二聚基共聚Poly（二甲基硅氧烷）-b-Poly（二甲基硅?...

Watch this Scientific Journal Video about Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration at JoVE.com

Obtention of Giant Unilamellar Hybrid Vesicles by Electroformation and Measurement of their Mechanical Properties by Micropipette Aspiration

该协议的目标是通过微移液吸气可靠地测量巨型囊泡的膜机械性能。

通过电形成和微移液器测量其机械性能，对巨型Unilamellar混合囊泡的吸收

Giant vesicles obtained from phospholipids and copolymers can be exploited in different applications: controlled and targeted drug delivery, biomolecular ...

该协议有助于使用微管吸气技术可靠地测量合成和真正的聚合物脂囊泡的膜机械性能。这是唯一允许在单个实验中对膜灵活性和不稳定性进行伸长的技术。该协议涉及一系列过程，从囊泡制备到机械评估。耐心和解决任何技术问题非常重要。这些技术的可视化对于了解如何正确处理毛细管表面以及如何执行强制性预应力步骤至关重要。显示囊泡无缺陷。演示程序将是马丁·福奎尼翁，一个博士生从实验室工作，研究混合聚合物脂囊体的发展。在开始手术之前，将冷玻璃微管毛细管垂直放入支架中。降低持有人，直到提示浸入新鲜准备的葡萄糖牛血清白蛋白溶液过夜。到了第二天早上，通过毛细管动作，溶液应该已经上升了大约一厘米。使用 500 微升玻璃注射器，配备柔性熔融石英毛细管，用葡萄糖溶液填充每个移液器。然后从每个移液器中吸出溶液，然后用新鲜葡萄糖溶液多次重新填充移液器，直到去除所有血清。要准备电热室，首先用适当的有机溶剂清洁 ITO 幻灯片，然后用欧姆表识别导电表面。用胶带将电线连接到每个滑轨的导电侧。将一个毛细管浸入安培溶液中，直到毛细管作用收集了约 5 微升溶液。将加载的毛细管与一个玻璃 ITO 板的中心接触，然后轻轻地将溶液铺在幻灯片上。当溶剂完全蒸发时，将溶液再次涂抹两次，正如刚刚演示的一样。在沉积区域周围打开的 O 环垫片的两侧添加一层无硅润滑脂之前。接下来，将第二个 ITO 玻璃板的导电面放在空间器顶部，将电化室放在真空下 3 小时，以去除任何有机溶剂的痕迹。对于巨型单体囊铁的电化，将电线插入发电机。将发电机频率设置为 10 赫兹，将振幅设置为 2 伏特，峰值为峰值。设置电压后，使用装有0.8毫米内径针头的注射器将一毫升0.1摩尔蔗糖溶液注入腔室，并在施加的电压和频率下将腔室保持75分钟。在电化结束时，关闭发电机。并使用一毫升注射器吸出少量溶液，直到室内产生气泡。稍微倾斜腔室，将气泡移入腔室，并帮助囊泡从滑动表面分离。将整个溶液体积吸入注射器中。然后，将囊泡溶液转移到一毫升塑料管中。设置材料进行微管理，吸气形成水流，一罐纯净水，到一个支架上。在提升油箱时轻轻敲击，消除任何气泡，并产生正压。用新鲜的葡萄糖溶液填充血清涂层毛细管，直到尖端形成滴。从金属支架上取下注射器管，在支架的末尾产生轻微的水流，然后倒置毛细管，将葡萄糖滴连接到水流。然后，将毛细管和支架拧在一起。要定位移液器，请将两个玻璃滑梯与真空润滑脂一起从定制的铝制舞台粘合。将幻灯片安装到显微镜舞台上。使用一毫升移液器，在两个幻灯片之间形成半月板，其葡萄糖为0.1摩尔葡萄糖。将移液器及其支架放在微操纵器的马达装置上。拧紧夹紧旋钮，并在粗模式下使用控制面板操纵手柄。降低葡萄糖半月板附近的微移管。使用精细模式将尖端的位置调整到半月板的中心。将尖端浸入葡萄糖中，清洁其外表面和内表面。几分钟后，从半月板中取走毛细管，用新鲜的半月板代替葡萄糖。在0.1摩尔蔗糖中吸气两个微升的巨型Unilamellar囊泡，吸入20毫升微管尖端。将囊泡引入半月板。使用显微镜观察滑室底部的囊泡。当囊泡稍微放气时，重新插入吸液器，并聚焦在移液器的尖端。然后将水箱的基线高度设置为停止粒子运动的压力。用矿物油包围半月板，防止蒸发。要执行微移液器吸气实验，请将移液器尖端降低至半月板。产生少量的吸力来吸气囊泡。所选囊泡的膜应轻微波动，不应出现任何可见的缺陷。使用微操纵器将移液器提升至较高水平，将吸气囊泡与其他囊泡分离。将水箱降低至约 10 厘米，以预应力囊泡，然后提高水箱以将压力恢复至初始值。从0.5厘米的高度，慢慢降低吸力，直到达到膜波动的压力。然后增加压力，以清楚地可视化一个舌头在尖端，投影长度几微米。要确定弯曲模量，请增加吸力压力，一次一微米，以循序渐进的方式。直到达到 0.5 至 0.8 毫纽顿/米。等待五秒钟，并在每一步后拍摄舌头的快照。确定区域可压缩模量，和解压和应变继续增加吸压从0.5毫纽顿每米，直到破裂张力达到。在这个代表性实验中，POPC的区域可压缩模数和解压菌株与文献中的预期完全一致。在此表中，可以观察到所获取的聚合物体的典型值。请注意，从二块共聚合物获得的膜的韧性远远大于从三块共聚合物获得的膜的韧性。有趣的是，使用二块共聚一体，有可能获得一个巨大的混合无酰胺脂聚合物囊泡，表现出比脂质体测量更坚固的韧性。该协议可以帮助测量囊泡与移液器，例如，测量膜通过状态冲击的渗透性。确保以严谨和精确度完成每个步骤，尤其是在设置论坛连接时。通过测量改性囊泡中主要边界的线张力，利用该技术了解膜裂变的物理起源。

Research

JoVE Journal

Chemistry

Fabricating Nanogaps by Nanoskiving

制造由Nanoskiving Nanogaps的

There are several methods of fabricating nanogaps with controlled spacings, but the precise control over the sub-nanometer spacing between two ...

科研

化学

Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides

生物分子有序结构由短肽的自组装形成

In nature, complex functional structures are formed by the self-assembly of biomolecules under mild conditions. Understanding the forces that control ...

Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties

Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties

非均匀掺Pr的SrTiO的合成<sub&gt; 3</sub&gt;陶瓷及其热电性能

We demonstrate a novel synthesis strategy for the preparation of Pr-doped SrTiO3 ceramics via a combination of solid state reaction and spark plasma ...

Synthesis and Characterization of Fe-doped Aluminosilicate Nanotubes with Enhanced Electron Conductive Properties

以增强电子导电性能的合成与表征Fe掺杂碳纳米管硅铝的

The goal of the protocol is to synthesize Fe-doped aluminosilicate nanotubes of the imogolite type with the formula (OH)3Al2-xFexO3SiOH. Doping with Fe ...

Measurement of Particle Size Distribution in Turbid Solutions by Dynamic Light Scattering Microscopy

通过动态光散射显微镜混浊解决方案粒度分布的测定

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a ...

TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method

TiO2-coated Hollow Glass Microspheres with Superhydrophobic and High IR-reflective Properties Synthesized by a Soft-chemistry Method

二氧化钛<sub&gt; 2</sub与由软化学法合成的超疏水性和高IR反射属性&gt;涂覆的空心玻璃微球

This manuscript proposes a soft-chemistry method to develop superhydrophobic and highly IR-reflective hollow glass microspheres (HGM). The anatase TiO2 ...

Fabrication and Testing of Photonic Thermometers

光子温度计的制作与测试

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being ...

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

C 型60/石墨烯混合纳米结构的制备与表征

Physical thermal deposition in a high vacuum environment is a clean and controllable method for fabricating novel molecular nanostructures on graphene. We ...

Membrane Remodeling of Giant Vesicles in Response to Localized Calcium Ion Gradients

局部钙离子梯度对大泡囊膜重塑的响应

In a wide variety of fundamental cell processes, such as membrane trafficking and apoptosis, cell membrane shape transitions occur concurrently with local ...

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties

解析高强共聚物芳纶纤维使其力学性能的测定

Traditionally, soft body armor has been made from poly(p-phenylene terephthalamide) (PPTA) and ultra-high molecular weight polyethylene. However, to ...