Name: generation of scalable, metallic high-aspect ratio nanocomposites in a biological liquid medium
Uploaded: 2015-07-08T15:00:00.000+00:00
Duration: 13 min 34 s
Description: Watch this Scientific Journal Video about Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium at JoVE.com

The authors would like to acknowledge the technical assistance of Alfred Gunasekaran in electron microscopy studies at the Institute of Micromanufacturing at Louisiana Tech University, and Dr. Jim McNamara for assistance with additional microscopy studies. The work described was supported in part by Louisiana board of Regents PKSFI Contract No. LEQSF (2007-12)-ENH-PKSFI-PRS-04 and the James E. Wyche III Endowed Professorship from Louisiana Tech University (to M.D.).

1.规划实验<ol><li>确定所需的合成铜纳米复合材料的体积。在此基础上，选择一些体积小烧瓶（25 平方厘米），或在准备材料如下所示大瓶。 </li><li>对于此合成中，使用一个37℃培养箱，用5％的CO 2和至少40％的湿度。确保这种培养箱可用，并且，它不会被重复干扰比合成的周期（大约24小时）。 注意:反复开闭的保育箱的肯定会引起温度的波动，这可能会导致该纳米复合材料结构的改变的合成。 </li></ol> 2.准备材料<ol><li>制备实验开始前新鲜的所有材料，通过加入固体材料对溶剂权之前合成是开始。保持原液的胱氨酸和铜的原料在液体长时间b乘积安伏的实验，不推荐并可能导致不同的结果。一旦从供应商处打开，一直原料干燥通过包装容器用Parafilm的顶部。 注意:下面的协议被用作用于在使用7微升胱氨酸，6643微升无菌水，350微升CNPS的的25cm 2细胞培养烧瓶中反应的一个例子。 </li><li>制备2毫克/毫升溶液的铜纳米颗粒的通过称出至少2毫克CNPS的。在这一步戴一次性手套，以防止CNPS与皮肤接触的可能。将纳米粒子在一个空的无菌16毫升玻璃管形瓶中。 <ol><li>向含有CNPS小瓶，在适当的体积加无菌去离子水，使2毫克/毫升溶液，并旋涡振荡溶液，持续20秒，以提供合成开始之前的纳米颗粒的分散体（至少1毫升总体积建议）。不填小瓶超过一半的水，因为这会抑制由涡旋混合。 CNPS WIL升快速沉降到小瓶的底部，并会出现暗的颜色（灰色到黑色）。 </li><li>超声清洗在室温下17分钟的CNP溶液合成开始之前提供的CNPS最大分散。定期检查，以确保CNPS是由于混合，超声。一个成功的超声处理后，CNPS保持在溶液中至少30分钟，悬浮，溶液颜色深。 </li></ol></li><li>称出胱氨酸的足够的质量以使72.9毫克/毫升溶液用于合成。因为胱氨酸不直接溶于水，放置称量胱氨酸在抗静电计量容器中。 <ol><li>称重含有胱氨酸容器，添加无菌，1M的NaOH足够体积，以使胱氨酸完全溶解。例如，完全溶解7.29毫克胱氨酸在100μl的1M氢氧化钠，使一个72.9毫克/毫升溶液。 </li><li>为了保持无菌的条件下，进行这一步在无菌流组织培养罩。 注意:氢氧化钠在1M的浓度是苛性，因此在此步骤中，以防止浓NaOH的皮肤接触穿一次性手套</li></ol></li><li>工作在无菌组织培养罩，与6643微升无菌水加7微升胱氨酸到无菌合成烧瓶第一，让孵育在孵化30分钟，在37℃下用该烧瓶帽排气（疏松的），以提供有效的混合。重悬2毫克/毫升的CNP溶液通过涡旋30秒，因为CNPS将已在超声步骤后结算。 <ol><li>添加足够的CNP溶液到合成烧瓶（使用无菌技术），以保持下列组分比率:将1份胱氨酸，50份CNPS，和949份无菌水中的25cm 2细胞培养烧瓶，开始合成。例如，对于一个7毫升合成量，结合7微升胱氨酸原液，350微升CNPS的，和6643微升无菌水。更换盖在烧瓶并拧紧，以便它是SECUR即</li><li>结合所有成分的合成后，轻轻在烧瓶中纷飞的4-5倍混合。放置烧瓶中的CO 2培养箱中并通过松开帽，以便将有进出合成在烧瓶的气体交换泄烧瓶中。 </li></ol></li><li>允许合成在孵化大约24小时运行。在合成过程中，人们可以观察到，用显微镜和眼睛，形成高度线性的复合材料。 注意:形成的结构的方法，可以在这个意义上，结构是最初难以检测突然发生，那么外观快速前进到增加密度。可形成24小时之前发生的，因此。该过程也可以通过眼睛观察到，一旦结构变得更大，它们的密度增加而增加。而产生的结构，可以随着时间的推移，在显微镜下，并用肉眼在稍后的时间点观察到的，连续中断的合成条件和温度会导致不良的综合结果。 </li><li>通过紧紧盖住合成烧瓶中，并存储该容器在冰箱（4℃）终止合成生物复合材料的。结构，一旦产生，在这种形式至少一年保持稳定。标签与合成的条件，包括部件利用，合成的日期和终止前的合成的孵育时间的烧瓶中。 </li></ol> 3.合成使用硫酸铜<ol><li>通过用硫酸铜盐代替CNPS进行自组装的合成。使用无菌技术，溶解至少2毫克硫酸铜在无菌去离子水足量，使一个2毫克/毫升溶液。的硫酸铜晶体容易进入溶液在该浓度，但是涡如果需要的小瓶中，并通过眼睛检查，以确保所有的晶体溶解。 </li><li>制备硫酸铜后，进行合成如先前描述的，使用硫酸铜代替CNPS。 注意:在使用硫酸铜作为起始材料的自组装纳米复合材料被认为是许多在比从CNPS合成结构最终形状更加一致。 </li><li>终止的硫酸铜生物复合材料的合成，作为CNP复合材料（步骤2.6），并将其储存长期在4℃。 </li></ol> 4.表征和处理生物材料的后期合成的<ol><li>从定性和CNPS从硫酸铜由白色光镜9和电子显微镜得出9生物复合材料。 <ol><li>为表征和生物复合材料的合成后通过白光显微镜检查，使用倒置显微镜作为复合材料会沉淀到烧瓶的底部表面铺设烧瓶平坦的几分钟之内，并且然后可以带入焦点。使用显微镜上的明场设置，最大限度生物复合材料和液体介质之间的对比。从CNPS和警察衍生复合材料每硫酸都将出现明显的不透明的颜色，但反应的CNP聚集会出现颜色很深。 <ol><li>使用连接到显微镜的数码相机来捕获复合材料的图像。的长度为各个构造A范围将被观察到。 </li></ol></li><li>为表征和生物复合材料的合成后的检查和储存在4℃后，让烧瓶来室温至少15分钟的烧瓶将初步形成在除去从冰箱，这将掩盖有效聚焦而进行显微成像缩合。允许平衡至室温后，擦拭烧瓶的顶面和底面，用干净的纸巾最大化显微成像质量。 </li><li>当30秒的工作或成像已经存储长期复合材料，涡流烧瓶解离形成而在冰箱复合材料的团块。混匀后，检查结构，倒置MICroscope确保已经聚集分离，并在必要时重复涡旋。 </li><li>使用倒置白光显微图像，以评估合成的功效，使用CNPS一个给定的实验。例如，记录的未反应CNPS中用于从烧瓶带有不同参数的CNP衍生生物复合材料，如合成的时间合成烧瓶存在或不存在。 注意:个别CNPS太小观察用光学显微镜，但未反应的CNP聚合将显示为圆形和暗的物体，而相比之下，成功地合成了CNP-复合材料将具有高的纵横比，线性形式，并将具有一系列不同的长度。避免进行合成过长的一段时间终止之前的，因为这将导致在高度支化的"海胆"型结构，这是难以分散成一旦形成单个结构。 </li><li>使用白色倒光镜评估疗效的合成使用硫酸铜一个给定的实验。由于硫酸铜变为完全进入溶液使用此协议，该解决方案会出现比从合成使用CNPS溶液少暗。通过比较烧瓶用不同的合成条件，如合成的终止时间之前文件的硫酸铜复合材料的大小和程度。 注意:成功合成复合材料将表现出一系列不同的长度。避免进行合成过长的一段时间终止之前的，因为这将导致在复合材料中，其中一些将在结构"海胆状"的高度支化的聚集体，并且其很难分散成一旦形成单独的结构。 </li></ol></li><li>专心生物复合合成后，在离心管中的复合材料的离心分离机的解决方案。添加6毫升任CNP衍生结构或硫酸衍生的铜结构的至15ml离心管中。离心10分钟在500×g离心在室温形成沉淀。对于较小的体积，加入500μl结构的解决方案，以0.6毫升大小的试管。离心机在2000×g离心在RT至少10分钟，以形成颗粒。 <ol><li>离心足够长的时间（至少10分钟为microfuges）后，保存可观察沉淀在管所在的建筑物集中通过仔细除去上清液沉淀上面的底部。从硫酸铜衍生生物复合材料结构出现蓝色的颜色和CNPS衍生结构较深（灰色至黑色）。 </li><li>添加更多的复合材料，以该管并重复该过程以相同的管，如果需要集中的结构。驱散浓缩粒料，加入溶液到管所需体积，并涡旋为10-30秒。 </li></ol></li><li>声处理结构一旦形成，要移动的组织的平均群体大小（长度），以较低的值。结构发生在无菌去离子水，超声在乐AST 10分钟。使用该方法，随着时间的推移，结构变得支离破碎和平均长度（见文本图6）小。用倒置的白色光镜，数码相机复合尺寸不同时代超声文档更改。 </li></ol>

<ol>
	<li>Klinman, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+copper-enzyme+family+of+dopamine+beta-monooxygenase+and+peptidylglycine+alpha-hydroxylating+monooxygenase:+resolving+the+chemical+pathway+for+substrate+hydroxylation.">The copper-enzyme family of dopamine beta-monooxygenase and peptidylglycine alpha-hydroxylating monooxygenase: resolving the chemical pathway for substrate hydroxylation.</a> The Journal of biological chemistry. 281, 3013-3016 (2006).</li><li>Uauy, R., Olivares, M., Gonzalez, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Essentiality+of+copper+in+humans.">Essentiality of copper in humans.</a> The American journal of clinical nutrition. 67, 952S-959S (1998).</li><li>Karlsson, H. L., Cronholm, P., Gustafsson, J., Copper Moller, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=oxide+nanoparticles+are+highly+toxic:+a+comparison+between+metal+oxide+nanoparticles+and+carbon+nanotubes.">oxide nanoparticles are highly toxic: a comparison between metal oxide nanoparticles and carbon nanotubes.</a> Chemical research in toxicology. 21, 1726-1732 (2008).</li><li>Parekh, G., 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=Layer-by-layer+nanoencapsulation+of+camptothecin+with+improved+activity.">Layer-by-layer nanoencapsulation of camptothecin with improved activity.</a> International journal of pharmaceutics. 465, 218-227 (2014).</li><li>Harrington, M. J., Masic, A., Holten-Andersen, N., Waite, J. H., Fratzl, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Iron-clad+fibers:+a+metal-based+biological+strategy+for+hard+flexible+coatings.">Iron-clad fibers: a metal-based biological strategy for hard flexible coatings.</a> Science. 328, 216-220 (2010).</li><li>Keyson, D., 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=CuO+urchin-nanostructures+synthesized+from+a+domestic+hydrothermal+microwave+method.">CuO urchin-nanostructures synthesized from a domestic hydrothermal microwave method.</a> Materials Research Bulletin. 43, 771-775 (2008).</li><li>Liu, B., Zeng, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesoscale+organization+of+CuO+nanoribbons:+formation+of+'dandelions'.">Mesoscale organization of CuO nanoribbons: formation of 'dandelions'.</a> J Am Chem Soc. 126, 8124-8125 (2004).</li><li>Peng, M., 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=Controllable+synthesis+of+self-assembled+Cu2S+nanostructures+through+a+template-free+polyol+process+for+the+degradation+of+organic+pollutant+under+visible+light.">Controllable synthesis of self-assembled Cu2S nanostructures through a template-free polyol process for the degradation of organic pollutant under visible light.</a> Materials Research Bulletin. 44, 1834-1841 (2009).</li><li>Deodhar, S., Huckaby, J., Delahoussaye, M., DeCoster, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Aspect+Ratio+Bio-Metallic+Nanocomposites+for+Cellular+Interactions.">High-Aspect Ratio Bio-Metallic Nanocomposites for Cellular Interactions.</a> IOP Conference Series: Materials Science and Engineering. 64, 012014 (2014).</li><li>Montes-Burgos, I., 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=Characterisation+of+nanoparticle+size+and+state+prior+to+nanotoxicological+studies.">Characterisation of nanoparticle size and state prior to nanotoxicological studies.</a> Journal of Nanoparticle Research. 12, 47-53 (2010).</li><li>Wiogo, H. T., Lim, M., Bulmus, V., Yun, J., Amal, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stabilization+of+magnetic+iron+oxide+nanoparticles+in+biological+media+by+fetal+bovine+serum+(FBS).">Stabilization of magnetic iron oxide nanoparticles in biological media by fetal bovine serum (FBS).</a> Langmuir. 27, 843-850 (2011).</li><li>Yunker, P. J., Still, T., Lohr, M. A., Yodh, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suppression+of+the+coffee-ring+effect+by+shape-dependent+capillary+interactions.">Suppression of the coffee-ring effect by shape-dependent capillary interactions.</a> Nature. 476, 308-311 (2011).</li><li>Kahler, H., Lloyd Jr, B., Eden, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+Microscopic+and+Other+Studies+on+a+Copper&#8211;Cystine+Complex.">Electron Microscopic and Other Studies on a Copper&#8211;Cystine Complex.</a> The Journal of Physical Chemistry. 56, 768-770 (1952).</li><li>Furia, E., Sindona, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complexation+of+L-cystine+with+metal+cations.">Complexation of L-cystine with metal cations.</a> Journal of Chemical &amp; Engineering Data. 55, 2985-2989 (2010).</li><li>Hawkins, C., Perrin, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polynuclear+Complex+Formation.+II.+Copper+(II)+with+Cystine+and+Related+Ligands.">Polynuclear Complex Formation. II. Copper (II) with Cystine and Related Ligands.</a> Inorganic Chemistry. 2, 843-849 (1963).</li><li>Hallman, P., Perrin, D., Watt, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+computed+distribution+of+copper+(II)+and+zinc+(II)+ions+among+seventeen+amino+acids+present+in+human+blood+plasma.">The computed distribution of copper (II) and zinc (II) ions among seventeen amino acids present in human blood plasma.</a> Biochem. J. 121, 549-555 (1971).</li><li>Jensen, L. S., Maurice, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+sulfur+amino+acids+on+copper+toxicity+in+chicks.">Influence of sulfur amino acids on copper toxicity in chicks.</a> The Journal of nutrition. 109, 91-97 (1979).</li><li>Lee, Y., Choi, J. R., Lee, K. J., Stott, N. E., Kim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+synthesis+of+copper+nanoparticles+by+chemically+controlled+reduction+for+applications+of+inkjet-printed+electronics.">Large-scale synthesis of copper nanoparticles by chemically controlled reduction for applications of inkjet-printed electronics.</a> Nanotechnology. 19, 415604 (2008).</li><li>Hume, 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=Engineered+coiled-coil+protein+microfibers.">Engineered coiled-coil protein microfibers.</a> Biomacromolecules. 15, 3503-3510 (2014).</li></ol>

Authors have nothing to disclose.

而评估纳米材料包括CNPS的潜在毒性作用，有人指出，在长期，CNPS被从初始较为分散的颗粒分布到较大 ​​的聚集形式（ 图2）转化。在某些情况下，这些中生产在细胞培养皿，生物条件下高度聚集的地层，形成了从中央骨料含有"海胆"高度线性突起，令人联想起先前所述铜的6。应当指出的是，这里所示的条件下，CNPS的浓度加入到细胞中是次最大，因此不杀死所有的细胞在培养中（ 见图2）。从这些初步观察，实验然后通过消除的细胞培养条件依次多个组件（包括最终的细胞本身）继续寻找所需的合成邻其余关键零部件˚F线性铜生物复合材料。 我们发现，胱氨酸，原始​​细胞培养物的一个补充部分，当正确的生物条件下与CNPS结合时，可能会导致在转化的纳米颗粒形式的成包含两金属和生化成分由​​EDX分析所指示高度线性生物复合材料通过扫描制备的样品的电子显微镜（ 图5）。因此，硫，这是不存在于起始的CNP材料，示出了在合成的生物复合材料的一个突出的峰，这表明铜和生化材料胱氨酸的组件对于所形成的线性结构是必不可少的。 它进一步表明，通过使用类似的合成条件，但用硫酸铜代替CNPS，高线性生物复合材料，也可以形成。事实上，使用硫酸铜及胱氨酸合成往往导致"更清洁"的连接D产品，在没有未反应CNPS是永远存在的，因为硫酸铜是完全溶解于水，将其作为溶剂使用在所有这里报道的合成的。此外，铜，硫酸生物复合材料区分自己从CNP衍生的复合材料保留了蓝色的颜色，这是根据材料的离心明显。 此前其他研究小组研究了铜胱氨酸复合物和定义一些关键的化学性质。例如，卡勒等人证明的铜胱氨酸络合物在细纤维的形式，这是在干燥时明显，但不稳定的溶液13的形成。在其它实例中，与L-胱氨酸和不同的金属阳离子络合研究证实铜和胱氨酸复合物的形成在含水介质14和形成配合物可以是单核或多核，从胱氨酸有助于复合物形成15中的硫。许多研究报告都胱氨酸和铜在生物系统之间编相互作用。例如，在生理pH下，铜（II）离子与组氨酸和胱氨酸在模拟的血浆坐标以形成含有氨基酸复合物16，以及硫被证明是保护性防止雏鸡17铜的毒性。因此这些发现支持与铜原料中的合成方法，用于形成线性生物复合络合胱氨酸的重要作用。 此时一个合成策略尚未鉴定出可直接控制这里显示个别线性生物复合材料的长度。然而，在所描述的合成所确定的关键步骤包括:1）通过起始原料合成掺入CNPS的情况下的超声处理分散性好; 2）使用新鲜制备CNPS，硫酸铜，和胱氨酸为有效合成复合材料的; 3）使合成在烧瓶中以保持原状的incubat或者至少6小时; 4）避免"过度反应"的条件，其中支"顽童"型，复合材料汇总表。 合成完成后，它表明了结构的超声处理可以有效地利用，以减少结构的平均大小（长度）。声波处理进行更小的结构可以在诸如细胞摄取或其他生物复合-细胞相互作用帮助。如先前已经报道，通过与胱氨酸改变了测量ζ电位从正到一个较少电荷（负）形式9结合该合成期间充电CNPS的稳定化。这种变化分管可能有助于解释为什么形成的复合材料展在干燥的形式或液体介质，这使得处理结构的方便多了很少的聚集。 由于这些CNP衍生和硫酸铜衍生结构的报道合成是öUT在液体介质，可以预料，该过程可以是高度可扩展的，这意味着与组件和合成条件的正确的比例，用在这里毫升合成配方可以放大或缩小，以包括数百毫升以上的，并将因此而被预期以得到更多的最终产品，以及。由于这些生物复合材料的金属（铜）成分，它是相当简单离心（ 图6）集中合成产物。从CNP形成起始材料生物复合材料保留较暗的颜色，一旦浓缩成粒料，可能是由于未反应的氧化铜纳米粒子（ 图6）。相比较而言，当浓缩成粒料硫酸铜生物复合材料具有一个蓝色的颜色，用硫酸铜与各级水化18的特性一致。 新颖的合成这里报告也是可扩展的，即自组装林耳结构从纳米尺度的微观尺度缩放为使用电子显微镜（ 图4）和传统的白光显微图像示出（ 图3和6）。有趣的是注意到，最近，工程化的卷曲螺旋蛋白微纤维被报道，可以纳入姜黄素这允许根据荧光照明19可以观察到所形成的纤维。类似的策略可能掺入间隔物或标记试剂引入这里报告提供生产用于成像更大的结构和/或增强的线性复合材料。

Copper is a highly reactive metal that in the biological world is essential in some enzyme functions 1,2, but in higher concentrations is potently toxic including in the nanoparticulate form 3,4. Concern over copper toxicity has become more relevant as CNPs and other copper-based nanomaterials are utilized, due to the increased surface area/mass for nanostructures. Thus, even a small mass of copper, in nanoparticle form, could cause local toxicity due to its ability to penetrate the cell and be broken down into reactive forms. Some biological species can complex with and chelate metal ions, and even incorporate them into biological structures as has been described in marine mussels 5. In studying the potential toxic effects of nanomaterials 4, it was discovered that over time, and under biological conditions used for typical cell culturing (37 &#176;C and 5% CO2), stable copper biocomposites could be formed with a high-aspect ratio (linear) structure.
By a process of elimination, the initial discovery of these linear biocomposites, which occurred in complete cell culture media, was simplified to a defined protocol of essential elements needed for the biocomposites to self-assemble. Self-assembly of two types of highly linear biocomposites was discovered to be possible with two starting metal components: 1) CNPs and 2) copper sulfate, with the common biological component being cystine. Although more complex, so called &#8220;urchin&#8221; and &#8220;nanoflower&#8221; type copper-containing structures with nanoscale and microscale features have been previously reported, these were produced under non-biological conditions, such as temperatures of 100 &#176;C or greater 6-8. To our knowledge, synthesis of individual, linear copper-containing nanostructures that are scalable in liquid phase under biological conditions has not been previously described. 
One of the starting materials utilized for synthesis of nanocomposites, namely CNPs, has been reported previously to be very toxic to cells 4. It has recently been reported that after the nanocomposites are formed, these structures are less toxic on a per mass basis than the starting NPs 9. Thus, the synthesis described here may be derived from a biological and biochemical reaction that has utility in stabilizing reactive copper species, both in the sense of transforming the NP form into larger structures and in producing composites less toxic to cells. 
In contrast to many other nanomaterial forms which are known to aggregate or clump upon interaction with biological liquid media 10,11, once formed, the highly linear composites described here avoid aggregation, possibly due to a redistribution of charge which has been previously reported 9. As detailed in the current work, this avoidance of aggregation is convenient for the purposes of working with the structures once formed for at least 3 reasons: 1) composite structures once formed may be concentrated using centrifugation and then easily dispersed again using vortex mixing; 2) formed structures can be decreased in average size by sonication for different periods of time; and 3) the formed linear structures may provide an additional tool for avoiding the recently described &#8220;coffee ring effect&#8221; 12 and thus provide a dopant for creating more evenly distributed coatings of materials, especially those containing spherical particulates.

<table><tbody><tr><td>Mini Vortexer</td><td>VWR (https://us.vwr.com)</td><td>58816-121</td><td></td></tr><tr><td>CO&lt;sub&gt;2&lt;/sub&gt; Incubator Model # 2425-2</td><td>VWR (https://us.vwr.com)</td><td>Contact vendor</td><td>Current model calalog # 98000-360</td></tr><tr><td>Eppendorf Centrifuge (Refrigerated Microcentrifuge)</td><td>Labnet (http://labnetinternational.com/)</td><td>C2500-R</td><td>Model Prism R</td></tr><tr><td>Cell Culture Centrifuge Model Z323K</td><td>Labnet (http://labnetinternational.com/)</td><td>Contact vendor</td><td>Current model Z206A catalog # C0206-A</td></tr><tr><td>Sonicator (Ultrasonic Cleaner)</td><td>Branson Ultrasonics Corporation (http://www.bransonic.com/)</td><td>1510R-MTH</td><td></td></tr><tr><td>Balance</td><td>Sartorius (http://dataweigh.com)</td><td></td><td>Model CP225D similar model CPA225D</td></tr><tr><td>Olympus IX51 Inverted Light Microscope</td><td>Olympus (http://olympusamerica.com</td><td>Contact vendor</td><td></td></tr><tr><td>Olympus DP71 microscope digital camera</td><td>Olympus (http://olympusamerica.com</td><td>Contact vendor</td><td></td></tr><tr><td>external power supply unit - white light for Olympus microscope</td><td>Olympus (http://olympusamerica.com</td><td>TH4-100</td><td></td></tr><tr><td>10X, 20X, and 40X microscope objectives</td><td>Olympus (http://olympusamerica.com</td><td>Contact vendor</td><td></td></tr><tr><td>Scanning Electron Microscope</td><td>Hitachi (http://hitachi-hitec.com/global/em/sem/sem_index.html)</td><td>model S-4800</td><td></td></tr><tr><td>Transmission Electron Microscope</td><td>Zeiss (http://zeiss.com/microscopy/en_de/products.html)</td><td>model Libra 120</td><td></td></tr><tr><td>Table Top Work Station Unidirectional Flow Clean Bench</td><td>Envirco (http://envirco-hvac.com)</td><td>model PNG62675</td><td>Used for sterile cell culture technique</td></tr></tbody></table>

generation of scalable, metallic high-aspect ratio nanocomposites in a biological liquid medium

该协议的目的是描述两种新型生物复合材料具有高纵横比结构的合成。该生物复合材料包括铜和胱氨酸，无论是与铜纳米颗粒（CNPS）或硫酸铜贡献的金属部件。合成是在生物条件下（37℃）和24小时后的自组装的复合材料的形式下是液体。一旦形成，这些复合材料是在两种液体介质和干燥形式高度稳定。该复合物由纳米规模向微型范围在长度和从几微米到直径25纳米。能量色散X射线光谱仪（EDX）的场发射扫描电子显微镜表明，硫存在于NP衍生线性结构，而这是从起始CNP材料不存在，从而证实胱氨酸作为硫在最终纳米复合材料的源。在综合这些线性纳米和微观复合材料，STR的长度多种多样uctures形成在合成容器。合成后的液体混合物的超声处理被证明有助于通过用超声处理的时间增加减少的平均长度控制的结构的平均尺寸。因为所形成的结构是高度稳定的，不结块，并形成有在液相，离心也可用于帮助浓缩和分离形成的复合材料。

图1示出的合成步骤，以形成在这项工作中描述的线性生物复合材料的流程图示意图。 CNPS或硫酸铜作为起始原料相结合，与无菌水，以形成2毫克/毫升溶液，该溶液混合并超声处理以提供更混合物，使该铜溶液然后在下面的比例混合用于合成:949份无菌水:50份混合铜:1份胱氨酸原液。实际体积可以根据这些比率来放大或缩小最后合成收率而增加或减少。孵育至少2小时所指示的，线性生物复合结构形成随着时间的推移可在正常的白光显微镜或通过肉眼观察作为在外观上的液体溶液的变化之后。 图2示出了从这些线性结构的完整的细胞培养基ö最初发现的代表性结果版本1.00一段82小时的。我们的实验室中进行不同的纳米材料，包括CNPS对正常细胞和癌细胞的潜在毒性的评价，并在图2所示的细胞是来自ATCC（CRL-2020）一个快速增长的脑肿瘤细胞系。一个关键的补充，以用于这些细胞的完整的媒体是胱氨酸，这原来是基本组分为什么这些线性结构分别在培养物形成（见下文和讨论部分）的发现。从CNPS的初始均匀分散从而迅速聚合成微结构（ 图2A和2B），随时间的更小的颗粒被清除，以及较大的聚集体形成（ 图2C和2D）。最后，细，线性结构更大的聚集体出现在相同的孔中（ 图2E-H），形成了"海胆"型先前文献报道使用非生物化学结构ogical方法6。最后的两个时间点，比较在69和82小时（ 图2G和2H，分别），表明大顽童式的结构发展仍然相当稳定，通过成像完全相同的现场指示。 为了解释为什么在细胞培养物在这些条件下这些海胆状结构进行了观察，我们开始消除媒体组件，以确定该要素可以分离。我们发现，一个关键组成部分和补充细胞培养基是胱氨酸，其通过排除过程最终被确定为自组装过程的必要成分。通过简化合成组件（参见图1），我们可以最终形成高纵横比（直链）结构中的液体，这可以显示随着时间的推移，从纳米颗粒形式，以线性形式进行改造，没有细胞的需要，或者任何另一小区培养组件（ 图3A-C）。 图4示出了用电子显微镜，包括一个透射电子显微镜（TEM）图像捕获纳米颗粒原料和成型线性纳米结构（ 图4A）的方法发现的新的结构的表征。代表性扫描电子显微照片（SEM）图像示为起始原料CNPS，从硫酸铜形成的纳米颗粒，和线性结构形成线性结构的原料（ 图4B-F，分别）。 要验证的生物复合材料含有胱氨酸或胱氨酸衍生材料作为复合材料的一个重要的生物成分，所形成的结构进行了由EDX用SEM显微镜分析。从分析的材料的代表性屏幕截图示于图5中 。重要的是，从CNPS比较CNPS和生物复合材料时，一个突出的出现硫峰（ 图5B），这是不存在的CNP起始材料（ 图5A）。使用硫酸铜作为起始材料（ 图5C），碳和氮的峰出现（ 图5D），这与胱氨酸的存在对本生物复合材料相一致的生物复合材料。 此时，合成过程中控制长度和复合材料的尺寸的方法尚未查明。 如图6，如果结构的平均尺寸可以在合成后进行控制，线性生物复合材料超声处理不同的时间不过，进行调查。随着超声处理的时间增加，已表明线性生物复合材料的平均粒径减小，如通过亮视野显微镜（ 图6A-D）所示。作为用于浓缩和分离形成的复合材料的方法，离心可以使用，并且， 如图6E-G，可见光粒料可以根据所用的量和离心力进行开发。 <img alt="图1" src="/files/ftp_upload/52901/52901fig1.jpg" /> 设计合成图1.代表流程图铜纳米粒子=铜纳米粒子。半胱氨酸=胱氨酸。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig1highres.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/52901/52901fig2.jpg" /> 在脑肿瘤细胞培养物如图2代表形成铜生物复合材料结构的完整的细胞培养基，一个代表性实验跟踪，在总计82小时的显示在细胞培养物含有的脑肿瘤细胞和CNPS（50微克/毫升）。图A和B显示培养孔时间为0时，CNPS后纷纷落户到井底。 ，面板CH表明随后的时间点在17，24，36，49，69，和82小时分别。板G和H代表在69和82小时，以同一领域。所有的图像使用明显微镜，以提高铜材料的对比获得。比例尺= 100微米为A + B，50微米的CE和25微米适用于F + G。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig2highres.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/52901/52901fig3.jpg" /> 图3。变换CNPS的线性生物复合。CNPS合并用胱氨酸和水， 如图1和在协议部分表示为7毫升的总体积。面板A显示了在时间0的合成容器，图B显示了3小时，和图C sh的OWS 6小时。图像用显微镜明表示与标尺（50微米）获得。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig3highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/52901/52901fig4.jpg" /> 图4.合成生物复合材料的电子显微镜表征面板（A）中:CNP的透射电镜原料（圆形）与成形线性复合材料。板（B）和（C）表示的起始CNPS表征使用SEM。面板（C）是（B）的放大图像。面板（D）示出从CNPS和胱氨酸形成复合材料的扫描电镜。面板（E）和（F）显示硫酸铜生物复合材料的中小企业。面板（F）是zoome（E）的三维图像。比例尺示于所有图像和中的 （A）= 200纳米，1微米（B）中，500纳米（C）中，5微米（D）中，2微米（E）和1微米（F ）。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig4highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图5" src="/files/ftp_upload/52901/52901fig5.jpg" /> 图5。EDX（SEM）分析原料和合成线性复合材料。采用EDX分析元素含量SEM扫描样本的屏幕快照。面板（A）=起动CNPS;面板（B）=从CNPS和胱氨酸生物复合材料;面板（℃）=硫酸铜起始原料，与面板（D）=复合来回米硫酸铜和胱氨酸。为峰标签，C =碳，O =氧，铜=铜，S =硫和N =氮。为元素的身份较大标签已被放在上面键峰便于观看。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig5highres.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图6" src="/files/ftp_upload/52901/52901fig6.jpg" /> 图6。变形例的线性组合大小和浓度后合成的。从硫酸铜合成线性结构进行了超声处理0，15，30，或60分钟，分别所示的面板（AD）。图像用显微镜明以200微米的所有图像显示比例尺获得。面板（EG），使用生物复合材料的浓度离心:6毫升从CNPS（来源线性结构&lt;STRONG&gt; E，左）和硫酸铜（E，右）显示10分钟后，在重力作用下沉降。用离心分离，在500×g离心10分钟，压实粒料形成（图F）。相同的材料的更小的体积（500微升）进行浓缩，如图（面板G）（CNP衍生结构示于左侧管和硫酸铜衍生的结构在右管）。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52901/52901fig6highres.jpg" target="_blank">请按此查看大版本这个数字。</a>

Watch this Scientific Journal Video about Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium at JoVE.com

Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium

在这里，我们提出了一个协议，以合成下生物条件和在液体介质新颖的，高宽比生物复合材料。的生物复合材料从纳米扩展到微米直径和长度。铜纳米粒子（CNPS）和硫酸铜结合胱氨酸是关键部件的合成。

可扩展的，金属的高宽比纳米复合材料在生物液体中产生

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

generation-scalable-metallic-high-aspect-ratio-nanocomposites

Universidad San Sebastian

Research

JoVE Journal

Bioengineering

9.0K 次观看.  Centenary College of Louisiana. 在这里，我们提出了一个协议，以合成下生物条件和在液体介质新颖的，高宽比生物复合材料。的生物复合材料从纳米扩展到微米直径和长度。铜纳米粒子（CNPS）和硫酸铜结合胱氨酸是关键部件的合成。 

视频: Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with sub-nanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.

We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.

在液体中使用液体池透射电子显微镜揭示材料的动态过程

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted ...

科研

工程学

Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding combined with layer transfer enables the replication of arbitrary surface patterns from a master structure onto the functional material. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes. In particular we demonstrate the fabrication of patterned transparent zinc oxide electrodes for light trapping applications in solar cells.

We describe a nanomoulding technique which allows low-cost nanoscale patterning of functional materials, materials stacks and full devices. Nanomoulding can be performed on any nanoimprinting setup and can be applied to a wide range of materials and deposition processes.

Nanomoulding功能材料，灵活的互补模式的复制方法，以奈米

We describe a nanomoulding technique which  allows low-cost nanoscale patterning of functional materials, materials stacks  and full devices. Nanomoulding ...

Manufacturing of Three-dimensionally Microstructured Nanocomposites through Microfluidic Infiltration

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite in&#64257;ltration of 3D interconnected microfluidic networks. The manufacturing of the reinforced beams begins with the fabrication of microfluidic networks, which involves layer-by-layer deposition of fugitive ink filaments using a dispensing robot, filling the empty space between filaments using a low viscosity resin, curing the resin and finally removing the ink.&#160;Self-supported 3D structures with other geometries and many layers (e.g.&#160;a few hundreds layers) could be built using this method. The resulting tubular micro&#64258;uidic networks are then infiltrated with thermosetting nanocomposite suspensions containing nanofillers (e.g.&#160;single-walled carbon nanotubes), and subsequently cured. The infiltration is done by applying a pressure gradient between two ends of the empty network (either by applying a vacuum or vacuum-assisted microinjection). Prior to the infiltration, the nanocomposite suspensions are prepared by dispersing nanofillers into polymer matrices using ultrasonication and three-roll mixing methods. The nanocomposites (i.e.&#160;materials infiltrated) are then solidified under UV exposure/heat cure, resulting in a 3D-reinforced composite structure. The technique presented here enables the design of functional nanocomposite macroscopic products for microengineering applications such as actuators and sensors.

Three-dimensional (3D) microstructured composite beams are fabricated through the directed and localized infiltration of nanocomposites into 3D porous microfluidic networks. The flexibility of this manufacturing method enables the utilization of different thermosetting materials and nanofillers in order to achieve a variety of functional 3D reinforced nanocomposite macroscopic products.

通过微流体渗透制备三维微结构纳米复合材料的制造

Microstructured composite beams reinforced with complex three-dimensionally (3D) patterned nanocomposite microfilaments are fabricated via nanocomposite ...

化学

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.

Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

使用N-零价金属芯纳米粒子的生成（2-氨基乙基）-3- aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of ...

Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo

Metallic implants, especially titanium implants, are widely used in clinical applications. Tissue in-growth and integration to these implants in the tissues are important parameters for successful clinical outcomes. In order to improve tissue integration, porous metallic implants have being developed. Open porosity of metallic foams is very advantageous, since the pore areas can be functionalized without compromising the mechanical properties of the whole structure. Here we describe such modifications using porous titanium implants based on titanium microbeads. By using inherent physical properties such as hydrophobicity of titanium, it is possible to obtain hydrophobic pore gradients within microbead based metallic implants and at the same time to have a basement membrane mimic based on hydrophilic, natural polymers. 3D pore gradients are formed by synthetic polymers such as Poly-L-lactic acid (PLLA) by freeze-extraction method. 2D nanofibrillar surfaces are formed by using collagen/alginate followed by a crosslinking step with a natural crosslinker (genipin). This nanofibrillar film was built up by layer by layer (LbL) deposition method of the two oppositely charged molecules, collagen and alginate. Finally, an implant where different areas can accommodate different cell types, as this is necessary for many multicellular tissues, can be obtained. By, this way cellular movement in different directions by different cell types can be controlled. Such a system is described for the specific case of trachea regeneration, but it can be modified for other target organs. Analysis of cell migration and the possible methods for creating different pore gradients are elaborated. The next step in the analysis of such implants is their characterization after implantation. However, histological analysis of metallic implants is a long and cumbersome process, thus for monitoring host reaction to metallic implants in vivo an alternative method based on monitoring CGA and different blood proteins is also described. These methods can be used for developing in vitro custom-made migration and colonization tests and also be used for analysis of functionalized metallic implants in vivo without histology.

Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo

In this video, we will demonstrate modification techniques for porous metallic implants to improve their functionality and to control cell migration. Techniques include development of pore gradients to control cell movement in 3D and production of basement membrane mimics to control cell movement in 2-D. Also, a HPLC-based method for monitoring implant integration in-vivo via analysis of blood proteins is described.

多尺度孔梯度，聚电解质和间接监测改性金属植入物<em&gt;在体内</em

Metallic implants, especially titanium implants, are widely used in  clinical applications. Tissue in-growth and integration to these implants in  the ...

生物工程

Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies

Procedures utilizing millifluidic devices for chemical synthesis and time-resolved mechanistic studies are described by taking three examples. In the first, synthesis of ultra-small copper nanoclusters is described. The second example provides their utility for investigating time resolved kinetics of chemical reactions by analyzing gold nanoparticle formation using in situ X-ray absorption spectroscopy. The final example demonstrates continuous flow catalysis of reactions inside millifluidic channel coated with nanostructured catalyst.

Millifluidic devices are utilized for controlled synthesis of nanomaterials, time-resolved analysis of reaction mechanisms and continuous flow catalysis.

Millifluidics的化学合成和时间分辨机理研究

Procedures utilizing millifluidic devices for chemical synthesis and time-resolved mechanistic studies are described by taking three examples. In the ...

Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion

We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the two metal oxides&#39; corresponding nanoparticles&#8212;the former being as small as 22 nm and the latter 15 nm. We fed two strains of bacteria, Shewanella algae and Pandoraea sp., with various concentrations of tungstate or molybdate ions. The concentrations of tungstate and molybdate were adjusted to make microcapsules of different length-to-diameter ratios. We found that the higher the concentration the smaller the nanoparticles were. The nanoparticles came in with three length-to-diameter ratios: 10:1, 3:1 and 1:1, which were achieved by feeding the bacteria respectively with a low concentration, a medium concentration, and a high concentration. The images of the hollow microcapsules were taken via the scanning electron microsphere (SEM). Their crystal structures were verified by X-ray diffraction (XRD)&#8212;the crystal structure of molybdate microcapsules is Na2MoO4 and that of tungstate microcapsules is Na2WO4 with Na2W2O7. These syntheses all were accomplished under a near ambient condition.

This work presents a protocol for manufacture sodium tungstate and sodium molybdate microcapsules via bacteria and their corresponding nanoparticles.

通过细菌矿物排泄合成钨酸钠和钼酸钠微胶囊

We present a method, the bacterial mineral excretion (BME), for synthesizing two kinds of microcapsules, sodium tungstate and sodium molybdate, and the ...

Large Area Substrate-Based Nanofabrication of Controllable and Customizable Gold Nanoparticles Via Capped Dewetting

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and high-density data storage have demonstrated the potential benefit of their use in industrial applications. These applications require precise control over nanoparticle size, spacing, and sometimes shape. These requirements have resulted in the use of time and cost intensive processing steps to produce nanoparticles, thus making the transition to industrial application unrealistic. This protocol will resolve this issue by providing a scalable and affordable method for the large-area production of nanoparticle films with improved nanoparticle control compared to the current techniques. In this article, the process will be demonstrated with gold, but other metals can also be used.

This protocol details a novel nano-manufacturing technique that can be used to make controllable and customizable nanoparticle films over large areas based on the self-assembly of dewetting of capped metal films.

大面积地下纳米化的可控、可定制金纳米粒子通过包盖湿法

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and ...

Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness and low bioactivity of metals. In this study, we have developed a new method towards fabricating a new type of bioactive and mechanically reliable porous metal scaffolds-densified porous Ti scaffolds. The method consists of two fabrication processes, 1) the fabrication of porous Ti scaffolds by dynamic freeze casting, and 2) coating and densification of the porous scaffolds. The dynamic freeze casting method to fabricate porous Ti scaffolds allowed the densification of porous scaffolds by minimizing the chemical contamination and structural defects. The densification process is distinctive for three reasons. First, the densification process is simple, because it requires a control of only one parameter (degree of densification). Second, it is effective, as it achieves mechanical enhancement and sustainable release of biomolecules from porous scaffolds. Third, it has broad applications, as it is also applicable to the fabrication of functionally graded porous scaffolds by spatially varied strain during densification.

Bioactive and mechanically reliable metal scaffolds have been fabricated through a method which consists of two processes, dynamic freeze casting for the fabrication of porous Ti, and coating and densification of the Ti scaffolds. The densification process is simple, effective and applicable to the fabrication of functionally graded scaffolds.

加工机械可调和生物活性金属支架的生物医学应用

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness ...

Controlling Particle Fraction in Microporous Annealed Particle Scaffolds for 3D Cell Culture

Microgels are the building blocks of microporous annealed particle (MAP) scaffolds, which serve as a platform for both in vitro cell culture and in vivo tissue repair. In these granular scaffolds, the innate porosity generated by the void space between microgels enables cell infiltration and migration. Controlling the void fraction and particle fraction is critical for MAP scaffold design, as porosity is a bioactive cue for cells. Spherical microgels can be generated on a microfluidic device for controlled size and shape and subsequently freeze-dried using methods that prevent fracturing of the polymer network. Upon rehydration, the lyophilized microgels lead to controlled particle fractions in MAP scaffolds. The implementation of these methods for microgel lyophilization has led to reproducible studies showing the effect of particle fraction on macromolecule diffusion and cell spreading. The following protocol will cover the fabrication, lyophilization, and rehydration of microgels for controlling particle fraction in MAP scaffolds, as well as annealing the microgels through bio-orthogonal crosslinking for 3D cell culture in vitro.

Minimizing the variability in the particle fraction within granular scaffolds facilitates reproducible experimentation. This work describes methods for generating granular scaffolds with controlled particle fractions for in vitro tissue engineering applications.

控制用于3D细胞培养的微孔退火颗粒支架中的颗粒分数

Microgels are the building blocks of microporous annealed particle (MAP) scaffolds, which serve as a platform for both in vitro cell culture and in vivo ...