Name: synthesis of multi-walled carbon nanotubes modified with silver nanoparticles and evaluation of their antibacterial activities and cytotoxic properties
Uploaded: 2018-05-10T12:30:00.000+00:00
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这项研究得到了 NRF 大学研究补助金 (2016) 和纳米材料技术开发项目的支持, 通过由科学和信息和通信技术部 (2017M3A7B8061942) 资助的韩国国家研究基金会 ()。

1. MWCNT 氧化
<ol><li>测量 30-50 毫克的 MWCNT 成一个50毫升的瓶子。缓慢地添加8毫升的 H2, 所以4: HNO3解决方案 (90% 初始浓度, 3:1 卷/卷) 的吸管与1毫升吸管提示。 注意: 此制剂必须在化学油烟机中进行。<ol>
<li>允许30分钟的放热反应完成。</li>
	</ol>
</li>
	<li>油脂实验溶液在 60-80 °c 和 160 W 为1小时, 直到 MWCNT 安定在瓶的底部。 注意: sonicator 的水位应该低于瓶子的顶端, 这样水就不会被引入瓶子里。</li>
	<li>把溶液转移到离心管上。<ol>
<li>用微, 加入30毫升蒸馏水滴到 MWCNT-COOH 溶液中。 注意: 在加蒸馏水的过程中会发生强烈的放热反应。慢慢加入蒸馏水, 让时间冷却。</li>
	</ol>
</li>
	<li>离心机的 MWCNT-COOH 溶液在 1.2万 x g 和室温15分钟。 注意: 在操作离心机时, 要确保离心机保持平衡, 在取样管对面放置一个与重量相同的管。</li>
	<li>用吸管和1毫升吸管端取出上清液。添加5毫升乙醇与吸管和1毫升吸管提示。用额外的 pipetted 乙醇冲洗瓶子的壁。离心溶液在 1.2万 x g 和室温15分钟。<ol>
<li>用 ph 纸测定上清液的 ph 值。重复洗涤和离心, 直到上清液 pH 值为中性。</li>
	</ol>
</li>
	<li>移除所有上清。加入1毫升蒸馏水, 在溶液中均匀沉淀和分散 MWCNT-COOH。冷冻干燥溶液在-60 摄氏度真空下直到干燥。</li>
</ol>2. 纳米银在 MWCNTs 上的沉积
<ol><li>将10毫克的 MWCNT-COOH 在50毫升圆锥管中, 稀释30毫升蒸馏水。油脂实验溶液在60°c 和 160 W 为 1 h。</li>
	<li>在50毫升圆锥管中放置6毫升的 0.1 N AgNO3 , 然后用18毫升蒸馏水稀释。油脂实验溶液在60°c 和 160 W 为 1 h。 警告: 添加 AgNO3与 MWCNTs 总质量的比例, 使 Ag 的总质量不超过20%。</li>
	<li>在添加 AgNO1后, 将 AgNO3解决方案添加到带吸管和1毫升吸管尖端的 MWCNTs 溶液中, sonicating 60 摄氏度和 160 w 的混合物继续 sonicating 3 h。</li>
	<li>离心溶液在 1.2万 x g 和室温15分钟, 并清除上清。离心溶液, 并去除上清液两次。</li>
	<li>将1毫升蒸馏水添加到银 MWCNTs 混合物中, 在溶液中均匀地分散沉淀。添加5毫升乙醇, 并允许反应在室温下进行1小时。</li>
	<li>离心溶液在 1.2万 x g 和室温15分钟, 并清除上清。</li>
	<li>用 ph 纸测定上清液的 ph 值。重复洗涤和离心, 直到清液 pH 值为中性。</li>
	<li>将1毫升蒸馏水加入银 MWCNTs, 均匀分散在溶液中。冷冻干燥溶液在-70 摄氏度真空下24小时。</li>
</ol>3. 抑制试验区
<ol><li>将18.12 克的 R2A 琼脂和1升的蒸馏水混合在烧瓶中。在121摄氏度的蒸压釜中消毒混合物15分钟。</li>
	<li>允许凝胶在室温下冷却。在硬化前, 在培养皿中放置10毫升凝胶以制备固体培养基。</li>
	<li>在固体培养基上放置100µL 细菌。使用吊具将细菌传播到固体介质中。 注意: 此程序必须在用酒精灯点燃的化学油烟罩中进行。</li>
	<li>在30摄氏度的盘子里孵化48小时。</li>
	<li>将3.12 克的 R2A 汤与1升的蒸馏水混合在一个烧瓶中。在121摄氏度的蒸压釜中消毒混合物15分钟。</li>
	<li>使用循环和针将生长的菌落转移到液体培养基中, 在 180 rpm 和30摄氏度的孵化器中孵化。</li>
	<li>以每小时 600 nm 的紫外分光光度法记录 OD (光学密度) 值以测量细菌生长。 注: R2A 琼脂是用于本试验, 而不是标准的米勒-韩丁琼脂, 因为 R2A 是首选琼脂生长的Methylobacterium.
</li>
	<li>在培养皿中放置10毫升准备好的 R2A 琼脂, 准备下琼脂。<ol>
<li>将3.12 克 R2A 汤和8克琼脂和1升蒸馏水混合在一起。在121摄氏度的高压釜中消毒混合物15分钟. 在底部琼脂上放置10毫升的凝胶。</li>
	</ol>
</li>
	<li>用微在无菌纸盘上加载50µL 银 MWCNTs 溶液。<ol>
<li>在紫外光照射下, 在真空室中干燥和消毒银 MWCNTs 样品30分钟。</li>
	</ol>
</li>
	<li>在琼脂上放置银 MWCNTs 样品。</li>
	<li>在30摄氏度孵育琼脂盘48小时。</li>
	<li>抑制12的度量区域。 注意: 引用中包含用于软件的说明。</li>
</ol>4. 抗菌试验
<ol><li>重复步骤3.1 至 3.7, 准备细菌培养。</li>
	<li>在最大 OD, 接种100µL 细菌成3毫升新鲜液体培养基与吸管和100µL 微吸管提示。</li>
	<li>在15毫升圆锥管中准备五50µL 的控制溶液样品。将以下各管加入: 1) 甲醇;2) 1000 µg/毫升 MWCNT COOH;3) 50 µg/毫升银 MWCNTs;4) 40 µg/毫升银 MWMWCNTs;5) 30 µg/毫升银 MWCNTs。</li>
	<li>孵育在180转每分钟和30°c, 直到控制是最大地活跃的由紫外分光光度的决定如上文所述。</li>
	<li>测量每个样品的 OD 值并计算麦克风浓度。OD 值与样品汤中的细菌细胞数量直接相关。</li>
	<li>将培养出来的细菌传播到固体培养基上。</li>
	<li>在30摄氏度孵化出48小时的菜肴。</li>
	<li>计数细菌菌落数和测量 CFU 值以确定抗菌活性12。 注意: 引用中包含用于软件的说明。</li>
</ol>5. 生存能力测定
<ol><li>从孵化器中取出培养细胞后, 吸入培养基, 用5毫升 PBS 的滴状洗涤清洗三次。</li>
	<li>在 PBS 中加入1毫升的胰蛋白酶-EDTA, 对洗涤后的细胞进行1分钟的吸入。<ol>
<li>点击盘子移除卡住的细胞。</li>
	</ol>
</li>
	<li>添加5毫升的 DMEM (Dulbecco 的改良鹰的培养基), 然后取出细胞。将样品离心 200 x 克3分钟, 取出上清液。<ol>
<li>加入1毫升的 DPBS 和混合。</li>
		<li>用自动计数机对解决方案的10µL 中的单元格进行计数。 注意: 使用的单元计数机的说明包含在引用13中。</li>
	</ol>
</li>
	<li>在含有 DMEM 溶液的六井板中, 每井放置 1 x 105的 AML12 细胞。培养基中含有 10% (v/v) 胎牛血清和1% 无菌抗生素。</li>
	<li>在 5% CO2/95% 空气环境中, 在37摄氏度孵育 8-12 小时的孵化板。</li>
	<li>用吸尘口从水井中吸取上清。<ol>
<li>添加每个样本包括控制, NMS-二甲基亚砜) 和30-40 µg/毫升银 MWCNT 到1毫升的 DMEM。</li>
		<li>37°c 在 5% CO2/95% 空气环境中孵化 8 h。</li>
	</ol>
</li>
	<li>清除上清液, 用5毫升的 PBS 冲洗样品。</li>
	<li>添加1毫升准备活/死套件 (20 µL 2 毫米 EthD-1 与5µL 4 毫米 calcein 是在亚砜在10毫升 PBS) 滴向细胞。</li>
	<li>在室温下孵育 30-45 分钟或37摄氏度, 用标准荧光显微镜在100X 或300X 测量荧光。</li>
</ol>6. 台盼蓝检测
<ol><li>根据步骤5.1 通过以上5.6.2 准备样品。</li>
	<li>移除上清。</li>
	<li>1毫升 1x DPBS 和醒酒的洗涤板。</li>
	<li>添加1毫升的胰蛋白酶到板块和孵化3分钟, 以分离细胞从文化。用细胞培养基冲洗板材, 收集细胞。将收集到的细胞放置在15毫升的试管中。</li>
	<li>离心管在 200 x g 和4°c 为3分钟。</li>
	<li>放弃上清。将1毫升新鲜培养基添加到细胞颗粒中, 重新分散细胞。</li>
	<li>添加10µL 的台盼蓝与10µL 分散细胞和计数的细胞与自动计数机。 注: 所使用的细胞计数机的说明包括在参考资料中。</li>
</ol>

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作者没有什么可透露的。

在这里, 我们报告了一个简单的方法来制备 MWCNTs 与沉积银纳米粒子。这种含银的纳米材料显示了大量的抗菌活性和极少的潜力, 不受控制地吸收银纳米粒子在体内。我们证明, 30 µg/毫升的合成银-MWCNTs 是一个有效的水平的抗菌活性的Methylobacterium. , 对哺乳动物肝细胞的毒性微乎其微。虽然在商业部门扩大之前需要对银 MWCNTs 进行额外的改进和生物安全评估, 但使用乙醇作为减少剂可以帮助生产环保和廉价的银 MWCNTs。
下面是演示的要点。用所开发的纳米材料可以破坏各种类型的细菌。有可能在纳米管表面上设计多个位置, 在这些地方可以沉积银纳米粒子。抗菌性能也可以通过控制在表面沉积的银纳米粒子的大小和数量来量身定做。所开发的纳米材料对细菌细胞是有毒的, 但在适当浓度下对人体和动物细胞无毒。
为抗菌活性提出了以下机制。银 MWCNT 纳米结构直接接触细菌细胞表面, 破坏细胞壁, 导致活性氧的二次氧化;这些过程导致氧化应激。银-MWCNT 纳米结构已被证实释放银离子, 抑制的法定人数传感的Methylobacterium , 从而抑制基因的表达, 控制生物膜的形成。
目前的协议的局限性将包括在人体试验中允许的不确定的最大数量的银纳米粒子和银 MWCNTs。在本议定书中, 银-MWCNTs 30 µg/毫升样品中所含的银色纳米粒子的数量平均估计为0.4 µg/毫升。这种浓度被视为与哺乳动物细胞的生物相容, 正如以前研究报告的6,7,8,9。MWCNTs 40 µg/毫升浓度的细胞毒性机制尚不确定, 但建议在培养皿的底部不附着血细胞可增加银 MWCNT 接触的可能性。今后可以对不同培养条件下的多种细胞类型的银纳米粒子进行详细的毒性研究。这些研究可以提供更多的信息, 关于银 MWCNT 与细胞相互作用的机制。

这项研究的最终目的是制造环境友好的抗菌纳米材料, 从而抑制形成生物膜的细菌的生长。这些抗菌纳米材料有可能克服常用化学药品或抗生素化合物的毒性和耐药性问题。生物膜是由多糖、蛋白质、核酸和血脂组成的水合胞外高分子物质 (EPS),1,2。生物膜防止外来物质的侵入, 帮助细菌大力生长3,4。生物膜引起气味和慢性传染性疾病5,6。例如, Methylobacterium通过附着在水始终存在的地方或难以确保连续进行细菌根除 (如空调热交换器、淋浴室和医疗设备) 而生长。这些类型的生物膜引起气味和慢性传染性疾病5,6。
通常, 化学物质或抗生素化合物用于抑制形成生物膜的细菌的生长。抗生素耐药性细菌的出现和对化学品的体内安全性的担忧促使人们需要开发新材料, 以防止生物膜的形成和抑制细菌的生长。
在本研究中, 合成了抗菌纳米材料, 无抗生素耐药性和毒性。银是一种众所周知的抗菌物质, 最近的纳米和纳米技术的发展导致了对金属纳米粒子的抗菌作用的积极研究7,8。最近的研究报告说, 纳米粒子的体积小, 体积比大, 导致抗菌活性增加9,10,11。
本文介绍的纳米材料将银纳米粒子与增强的抗菌性能和碳纳米管结合在一起, 从而增加了单位体积的表面积。制备的银纳米粒子-碳纳米管复合材料具有很大的抗菌性能和对人体和动物细胞的最小毒性。以前研究中的合成过程使用了诸如 NaBH4、甲酰胺、甲基酰胺和肼等有害还原剂。这个过程很复杂, 很危险, 而且耗时。这里报告的合成过程使用乙醇作为一种显著减少危险的还原剂。
测定了银 MWCNTs 的抑菌区和最低杀菌浓度;用活/死和台盼蓝法测定毒性和抗菌性能。最低抑制浓度 (MIC) 和线粒体毒性 (MTT) 检测没有执行, 因为不寻常的颜色的碳纳米管, 这将干扰的化验。最后, 确定了在不影响哺乳动物细胞的情况下, 防止Methylobacterium生长的最小浓度。

<table><tbody><tr><td>0.1 N silver nitrate</td><td>SIGMA-ALDRICH</td><td>1090811000</td><td></td></tr><tr><td>Carbon nanotube, multi-walled</td><td>Tokyo Chemical Industry Co., LTD</td><td>308068-56-6</td><td></td></tr><tr><td>R2A agar</td><td>MBcell</td><td>MB-R1129</td><td></td></tr><tr><td>R2A broth</td><td>MBcell</td><td>MB-R2230</td><td></td></tr><tr><td>&lt;em&gt;Methylobacterium spp.&lt;/em&gt;</td><td>KCTC</td><td>12618</td><td>from Korea Collection for Type Cultures Daejeon Korea 12618, Daejon, Korea</td></tr><tr><td>LIVE/DEAD Cell imaging Kit</td><td>ThermoFisher SCIENTIFIC</td><td>R37601</td><td></td></tr><tr><td>AML12</td><td></td><td></td><td>from Chungnam University, Dajeon, Korea</td></tr><tr><td>human PBMC</td><td>ATCC</td><td>PCS-800-011</td><td></td></tr><tr><td>TEM</td><td>JEOL</td><td>JEM-2100F</td><td></td></tr><tr><td>XRD</td><td>Rigaku</td><td>D/MAX 2500</td><td>Cu K photon source (40&lt;em&gt;k&lt;/em&gt;V, 100mA)</td></tr><tr><td>JuLI Br</td><td>NanoEnTek</td><td>JULI-BRSC&amp;nbsp;</td><td></td></tr></tbody></table>

synthesis of multi-walled carbon nanotubes modified with silver nanoparticles and evaluation of their antibacterial activities and cytotoxic properties

本研究采用水硫酸溶液处理多壁碳纳米管 (MWCNTs), 形成氧基功能基团。银 MWCNTs 是由还原沉积银从 AgNO3的水溶液中氧化 MWCNTs。鉴于碳纳米管的独特颜色, 不可能将其应用于最小抑制浓度或线粒体毒性检测, 以评估毒性和抗菌性能, 因为它们会干扰化验。测定了银 MWCNTs 的抑菌区和最低杀菌浓度, 并利用台盼蓝法测定了其毒性和抗菌性能, 不影响碳纳米管的颜色。

透射电镜 (TEM) 图像确认银 MWCNTs 的形成 (图 1A 和 1B)。表面电荷的变化证实了它们的成功合成。计算了 MWCNTs 上沉积的 Ag 粒子的大小 (图 1C)。平均微粒大小是大约3.83 毫微米。该合成银 MWCNTs 的 XRD 模式显示在图 1D中。峰值在 20-30°对应于 MWCNT;其余的峰值对应于 Ag。抗菌活动数据显示在图 2中。细菌菌落数量由Methylobacterium控件确认 (图 2A);增加甲醇减少了人口 103次 (图 2B), 并且加法 MWCNT-COOH 减少了人口 108时间 (图 2C)。在50µg/ml ag MWCNT (图 2D) 和40µg/ml ag MWCNT (图 2E) 样品中无法识别菌落。在20µg/mL Ag MWCNT 样品中, 人口减少了 105次 (图 2F)。在针对Methylobacterium (图 3) 的抑制测试区域中, 在添加了10µg/mL 时确定了抑制区域。在1µg/毫升浓度下未观察到抑制区。在细胞毒性试验中, 活体/死法 (图 4) 确认阴性控制 (图 4A) 中没有细胞毒性, 在使用甲醇时阳性控制 (图 4B) 中存在细胞毒性。增加了40µg/毫升 ag MWCNTs (图 4C) 揭示了一些细胞毒性, 然而增加30µg/毫升 ag MWCNTs (Figure 4D) 没有显示大量的细胞毒性。对该控件执行了一个台盼蓝检测 (图5) (图 5A), 甲醇 (图 5B), 40 µg/毫升 ag MWCNTs (图 5C) 和30µg/毫升 ag MWCNTs (图 5D) 样品。结果证实, 在30µg/毫升银 MWCNTs 中, 细胞毒性很少。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57384/57384fig1.jpg"> 图 1: 银 MWCNTs 的物理化学特性.(A) 和 (B)银 MWCNTs 的透射电镜图像;(C)通过 TEM 评估的银 MWCNTs 的大小分布 (n = 100);MWCNTs 的(D) XRD 模式<a href="/files/ftp_upload/57384/57384fig1large.jpg" target="_blank">请单击此处查看此图的更大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57384/57384fig2.jpg"> 图 2: 银 MWCNTs 相对于Methylobacterium的抗菌性评价。(A)控件, (B)甲醇, (C) MWCNT-COOH, (D) 50 微克/毫升的银 MWCNTs, (E) 40 微克/毫升的银 MWCNTs, 和(F) 30 微克/毫升的银 MWCNTs.<a href="/files/ftp_upload/57384/57384fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57384/57384fig3.jpg"> 图 3: 银 MWCNTs 的抑制试验区。
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57384/57384fig4.jpg"> 图 4: MWCNTs 显微照片的细胞生存性测定 AML12 荧光标记为死 (红) 和活 (绿) 细胞。(A)控件, (B)甲醇, (C) 40 微克/毫升 MWCNTs, 和(D) 30 微克/毫升的银 MWCNTs.<a href="/files/ftp_upload/57384/57384fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/57384/57384fig5.jpg"> 图 5:30 和 40μg/毫升银 MWCNTs 的台盼蓝化验.(A)控件, (B)甲醇, (C) 40 微克/毫升的银 MWCNTs, 和(D) 30 微克/毫升的银 MWCNTs. (红色: 死细胞; 蓝色: 活细胞)<a href="/files/ftp_upload/57384/57384fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties at JoV

Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

本研究通过多壁纳米碳纳米管的酸性氧化和银纳米粒子随后的还原沉积合成了抗菌纳米材料。用制备的纳米材料进行抗菌活性和细胞毒性试验。

银纳米粒子改性多壁碳纳米管的合成及其抗菌活性和细胞毒性的评价

In this study, multi-walled carbon nanotubes (MWCNTs) were treated with an aqueous sulfuric acid solution to form an oxygen-based functional group. Silver ...

synthesis-multi-walled-carbon-nanotubes-modified-with-silver

Universidad San Sebastian

Research

JoVE Journal

Bioengineering

10.2K 次观看.  Korea Institute of Science and Technology. 本研究通过多壁纳米碳纳米管的酸性氧化和银纳米粒子随后的还原沉积合成了抗菌纳米材料。用制备的纳米材料进行抗菌活性和细胞毒性试验。

视频: Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

科研

工程学

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

内部自组装脂质颗粒的简易制备碳纳米管稳定

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

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 ...

Synthesis of Functionalized Magnetic Nanoparticles, Their Conjugation with the Siderophore Feroxamine and its Evaluation for Bacteria Detection

In the present work, the synthesis of magnetic nanoparticles, its coating with SiO2, followed by its amine functionalization with (3-aminopropyl)triethoxysilane (APTES) and its conjugation with deferoxamine, a siderophore recognized by Yersinia enterocolitica, using a succinyl moiety as a linker are described.
Magnetic nanoparticles (MNP) of magnetite (Fe3O4) were prepared by solvothermal method and coated with SiO2 (MNP@SiO2) using the St&#246;ber process followed by functionalization with APTES (MNP@SiO2@NH2). Then, feroxamine was conjugated with the MNP@SiO2@NH2 by carbodiimide coupling to give MNP@SiO2@NH2@Fa. The morphology and properties of the conjugate and intermediates were examined by eight different methods including powder X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-Ray (EDX) mapping. This exhaustive characterization confirmed the formation of the conjugate. Finally, in order to evaluate the capacity and specificity of the nanoparticles, they were tested in a capture bacteria assay using Yersinia enterocolitica.

This work describes protocols for the preparation of magnetic nanoparticles, its coating with SiO2, followed by its amine functionalization with (3-aminopropyl)triethoxysilane (APTES) and its conjugation with deferoxamine using a succinyl moiety as a linker. A deep structural characterization description and a capture bacteria assay using Y. enterocolitica for all the intermediate nanoparticles and the final conjugate are also described in detail.

功能化磁性纳米粒子的合成及其与侧双磷铁氧胺的结合及其细菌检测评价

In the present work, the synthesis of magnetic nanoparticles, its coating with SiO2, followed by its amine functionalization with ...

Production of Metal Nanoparticles by Pulsed Laser-ablation in Liquids: A Tool for Studying the Antibacterial Properties of Nanoparticles

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of medicine. In addition to efforts to identify novel small-molecule antimicrobial drugs, there has been great interest in the use of metal nanoparticles as coatings for medical devices, wound dressings, and consumer packaging, due to their antimicrobial properties. The wide variety of methods available for nanoparticle synthesis results in a broad spectrum of chemical and physical properties which can affect antibacterial efficacy. This manuscript describes the pulsed laser-ablation in liquids (PLAL) method to create nanoparticles. This approach allows for the fine tuning of nanoparticle size, composition, and stability using post-irradiation methods as well as the addition of surfactants or volume excluders. By controlling particle size and composition, a large range of physical and chemical properties of metal nanoparticles can be explored which may contribute to their antimicrobial efficacy thereby opening new avenues for antibacterial development.

The antimicrobial properties of metals such as copper and silver have been recognized for centuries. This protocol describes pulsed laser-ablation in liquids, a method of synthesizing metal nanoparticles that provides the ability to fine tune the properties of these nanoparticles to optimize their antimicrobial effects.

液体中脉冲激光烧蚀制备金属纳米粒子:研究纳米粒子抗菌性能的工具

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of ...

生物工程

A Silver Nanoparticle Method for Ameliorating Biliary Atresia Syndrome in Mice

Biliary atresia (BA) is a severe type of cholangitis with high mortality in children of which the etiology is still not fully understood. Viral infections may be one possible cause. The typical animal model used for studying BA is established by inoculating a neonatal mouse with a rhesus rotavirus. Silver nanoparticles have been shown to exert antibacterial and antiviral effects; their function in the BA mouse model is evaluated in this study. Currently, in BA animal experiments, the methods used to improve the symptoms of BA mice are generally symptomatic treatments given via food or other drugs. The aim of this study is to demonstrate a new method for ameliorating BA syndrome in mice by the intraperitoneal injection of silver nanoparticles and to provide detailed methods for preparing the silver nanoparticle gel formulation. This method is simple and widely applicable and can be used to research the mechanism of BA, as well as in clinical treatments. Based on the BA mouse model, when the mice exhibit jaundice, the prepared silver nanoparticle gel is injected intraperitoneally to the surface of the lower liver. The survival status is observed, and biochemical indicators and liver histopathology are examined. This method allows a more intuitive understanding of both the establishment of the BA model and novel BA treatments.

This article describes in detail a method based on silver nanoparticles for ameliorating biliary atresia syndrome in an experimental biliary atresia mouse model. A solid understanding of the reagent preparation process and the neonatal mouse injection technique will help familiarize researchers with the method used in neonatal mouse model studies.

银纳米粒子法改善小鼠胆道闭锁综合征

Biliary atresia (BA) is a severe type of cholangitis with high mortality in children of which the etiology is still not fully understood. Viral infections ...

免疫与感染

Tangential Flow Ultrafiltration: A  &ldquo;Green&rdquo; Method for the Size Selection and Concentration of Colloidal Silver Nanoparticles

Nowadays, AgNPs are extensively used in the manufacture of consumer products,1 water disinfectants,2 therapeutics,1, 3 and biomedical devices4 due to their powerful antimicrobial properties.3-6 These nanoparticle applications are strongly influenced by the AgNP size and aggregation state. Many challenges exist in the controlled fabrication7 and size-based isolation4,8 of unfunctionalized, homogenous AgNPs that are free from chemically aggressive capping/stabilizing agents or organic solvents.7-13 Limitations emerge from the toxicity of reagents, high costs or reduced efficiency of the AgNP synthesis or isolation methods (e.g., centrifugation, size-dependent solubility, size-exclusion chromatography, etc.).10,14-18 To overcome this, we recently showed that TFU permits greater control over the size, concentration and aggregation state of Creighton AgNPs (300 ml of 15.3 &mu;g ml-1 down to 10 ml of 198.7 &mu;g ml-1) than conventional methods of isolation such as ultracentrifugation.19
TFU is a recirculation method commonly used for the weight-based isolation of proteins, viruses and cells.20,21 Briefly, the liquid sample is passed through a series of hollow fiber membranes with pore size ranging from 1,000 kD to 10 kD. Smaller suspended or dissolved constituents in the sample will pass through the porous barrier together with the solvent (filtrate), while the larger constituents are retained (retentate). TFU may be considered a "green" method as it neither damages the sample nor requires additional solvent to eliminate toxic excess reagents and byproducts. Furthermore, TFU may be applied to a large variety of nanoparticles as both hydrophobic and hydrophilic filters are available.
The two main objectives of this study were: 1) to illustrate the experimental aspects of the TFU approach through an invited video experience and 2) to demonstrate the feasibility of the TFU method for larger volumes of colloidal nanoparticles and smaller volumes of retentate. First, unfuctionalized AgNPs (4 L, 15.2 &mu;g ml-1) were synthesized using the well-established Creighton method22,23 by the reduction of AgNO3 with NaBH4. AgNP polydispersity was then minimized via a 3-step TFU using a 50-nm filter (460 cm2) to remove AgNPs and AgNP-aggregates larger than 50 nm, followed by two 100-kD (200 cm2 and 20 cm2) filters to concentrate the AgNPs. Representative samples were characterized using transmission electron microscopy, UV-Vis absorption spectrophotometry, Raman spectroscopy, and inductively coupled plasma optical emission spectroscopy. The final retentate consisted of highly concentrated (4 ml, 8,539.9 &mu;g ml-1) yet lowly aggregated and homogeneous AgNPs of 1-20 nm in diameter. This corresponds to a silver concentration yield of about 62%.

Tangential flow ultrafiltration (TFU) is a recirculation method used for the weight-based separation of biosamples. TFU was adapted to size-select (1-20 nm diameter) and highly concentrate a large volume of polydisperse silver nanoparticles (4 L of 15.2 &mu;g ml-1 down to 4 ml of 8,539.9 &mu;g ml-1) with minimal aggregation.

切向流超：A胶体银纳米粒子的大小选择与集中“绿色”方法

Nowadays, AgNPs are extensively used in the manufacture of consumer products,1 water disinfectants,2 therapeutics,1, 3 and biomedical devices4 due to ...

生物学

Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro

The antimicrobial activities of nanoparticles and nanostructured surfaces, such as silver, zinc oxide, titanium dioxide, and magnesium oxide, have been explored previously in clinical and environmental settings and in consumable food products. However, a lack of consistency in the experimental methods and materials used has culminated in conflicting results, even amongst studies of the same nanostructure types and bacterial species. For researchers who wish to employ nanostructures as an additive or coating in a product design, these conflicting data limit their utilization in clinical settings. 
To confront this dilemma, in this article, we present four different methods to determine the antimicrobial activities of nanoparticles and nanostructured surfaces, and discuss their applicability in different scenarios. Adapting consistent methods is expected to lead to reproducible data that can be compared across studies and implemented for different nanostructure types and microbial species. We introduce two methods to determine the antimicrobial activities of nanoparticles and two methods for the antimicrobial activities of nanostructured surfaces. 
For nanoparticles, the direct co-culture method can be used to determine the minimum inhibitory and minimum bactericidal concentrations of nanoparticles, and the direct exposure culture method can be used to assess real-time bacteriostatic versus bactericidal activity resulting from nanoparticle exposure. For nanostructured surfaces, the direct culture method is used to determine the viability of bacteria indirectly and directly in contact with nanostructured surfaces, and the focused-contact exposure method is used to examine antimicrobial activity on a specific area of a nanostructured surface. We discuss key experimental variables to consider for in vitro study design when determining the antimicrobial properties of nanoparticles and nanostructured surfaces. All these methods are relatively low cost, employ techniques that are relatively easy to master and repeatable for consistency, and are applicable to a broad range of nanostructure types and microbial species.

Evaluation of Antimicrobial Activities of Nanoparticles and Nanostructured Surfaces In Vitro

We introduce four methods to evaluate the antimicrobial activities of nanoparticles and nanostructured surfaces using in vitro techniques. These methods can be adapted to study the interactions of different nanoparticles and nanostructured surfaces with a broad range of microbial species.

体外评估纳米颗粒和纳米结构表面的抗菌活性

The antimicrobial activities of nanoparticles and nanostructured surfaces, such as silver, zinc oxide, titanium dioxide, and magnesium oxide, have been ...

<meta charset="utf8"></head><body> 氧化锌纳米颗粒的合成及其抗菌作用分析

Preparation of Zinc Oxide Nanoparticles and the Evaluation of their Antibacterial Effects

Nosocomial bacterial infections have become increasingly challenging due to their inherent resistance to antibiotics. The emergence of multidrug-resistant bacterial strains in hospitals has been attributed to the extensive and varied use of antibiotics, further exacerbating the problem of antibiotic resistance. Metal nanomaterials have been widely studied as an alternative solution for eradicating antibiotic-resistant bacterial cells. Metallic nanoparticles attack bacterial cells through various mechanisms, such as the release of antibacterial ions, generation of reactive oxygen species, or physical disruption, against which bacteria cannot develop resistance. Among the actively researched antimicrobial metal nanoparticles, zinc oxide nanoparticles, which are FDA-approved, are known for their biocompatibility and antibacterial properties. In this study, we focused on successfully developing a precipitation method for synthesizing zinc oxide nanoparticles, analyzing the properties of these nanoparticles, and conducting antimicrobial tests. Zinc oxide nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), ultraviolet/visible spectroscopy, and X-ray diffraction (XRD). Antibacterial tests were conducted using the broth microdilution test with the multidrug-resistant strains of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. This study demonstrated the potential of zinc oxide nanoparticles in inhibiting the proliferation of antibiotic-resistant bacteria.

<meta charset="utf8"></head><body>作者聚焦：探索氧化锌纳米颗粒在克服抗生素耐药性中的抗菌作用

In this study, zinc oxide nanoparticles were synthesized using a precipitation method. The antibacterial effect of the synthesized particles was tested against multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa bacterial strains.

氧化锌纳米颗粒的制备及其抗菌效果评价

Nosocomial bacterial infections have become increasingly challenging due to their inherent resistance to antibiotics. The emergence of multidrug-resistant ...

银纳米粒子改性多壁碳纳米管的合成及其抗菌活性和细胞毒性的评价

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此视频中的章节

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

内部自组装脂质颗粒的简易制备碳纳米管稳定

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

功能化磁性纳米粒子的合成及其与侧双磷铁氧胺的结合及其细菌检测评价

液体中脉冲激光烧蚀制备金属纳米粒子:研究纳米粒子抗菌性能的工具

银纳米粒子法改善小鼠胆道闭锁综合征

切向流超：A胶体银纳米粒子的大小选择与集中“绿色”方法

体外评估纳米颗粒和纳米结构表面的抗菌活性

氧化锌纳米颗粒的制备及其抗菌效果评价

氧化锌纳米颗粒的制备及其抗菌效果评价