这项工作得到了中国台湾科技部的支持, 其资助人数最多 105-2221-011-008, 还有先进的 Connectek Inc.、台北、台湾、中华民国的合同号 RD Ref. No. 6749 和 Dept. Ref. No. 011 通过国立台湾科技大学光电工程学院毕业。

注意: 使用乳胶手套、防护眼镜和实验室工作服进行实验。使用生物安全柜时, 打开橱柜风扇, 使柜门半闭。
1. 玻璃微珠的制备
<ol><li>将100个直径3毫米的玻璃珠放在一个100毫升的实验室瓶子里, 然后把它紧紧地盖住。</li>
	<li>高压釜的内容在120° c 为10分钟。</li>
	<li>让瓶子冷却到室温, 然后把它放在生物安全柜里。</li>
</ol>2. 性汤的制备 (LB)
<ol><li>在500毫升的实验室瓶中溶解8克的 LB-蓝诺克斯粉, 400 毫升的水。</li>
	<li>用 PTFE 磁性搅拌棒搅拌20分钟, 然后将其盖紧。</li>
	<li>高压釜的内容在120° c 为10分钟。</li>
	<li>把溶液冷却到室温, 放在生物安全柜里。</li>
	<li>使用吸管, 分的肉汤到八15毫升离心管在生物安全柜 (每12.5 毫升)。</li>
	<li>分将剩余的肉汤放入生物安全柜中的三100毫升的实验室瓶子中 (每瓶100毫升)。把三瓶瓶盖拧紧。把它们放在生物安全柜里</li>
</ol>3.希瓦藻类的培养
<ol><li>使用深冻超低温保存的菌株。</li>
	<li>在生物安全柜中, 用不锈钢刮刀从冷冻管中取出1毫升的冷冻材料, 并将其放入3.5 步中制备的离心管中。</li>
	<li>在37° c 孵化箱中孵育24小时的培养基。</li>
</ol>4. 用琼脂制作发酵皿
<ol><li>用100毫升的水将两片 LB-蓝诺克斯 (汤与琼脂) 溶入一个100毫升的实验室瓶子。</li>
	<li>用 PTFE 磁性搅拌棒搅拌20分钟, 然后将其紧紧地盖住。</li>
	<li>高压釜的内容在120° c 为10分钟。</li>
	<li>在生物安全柜中, 用手分100毫升的溶液放入4培养皿中, 确保每一个接收 ~ 25 毫升。让溶液冷却到室温。</li>
</ol>5. 单克隆细菌的制备
<ol><li>在生物安全柜中, 分别标明步骤2.6、#1、#2 和 #3 的三瓶。</li>
	<li>移液0.1 毫升的结果细菌悬浮在步骤3.3 到瓶子 #1。瓶盖的瓶子和摆动它的手1分钟, 得到一个均匀的解决方案。</li>
	<li>在步骤5.2 中, 将所合成的细菌液体的0.1 毫升移入瓶子 #2。瓶盖的瓶子和摆动它的手1分钟, 得到一个均匀的解决方案。</li>
	<li>在步骤5.3 中, 将所合成的细菌液体的0.1 毫升移入瓶子 #3。把瓶子盖上, 用手摇动1分钟以得到一个均匀的溶液。</li>
	<li>将瓶中的液体 #3 到步骤4.4 中准备的4种培养皿中, 每次使用0.02 毫升。</li>
	<li>把1.3 步准备好的玻璃珠放入4个培养皿中, 每道4珠。</li>
	<li>关闭培养皿的盖子, 用手摇动它们1分钟。</li>
	<li>将培养皿倒置, 在一个37° c 的孵化箱中孵育24小时。</li>
</ol>6. 单克隆细菌的增殖
<ol><li>在步骤2.5 中提取7根管子。</li>
	<li>在步骤5.8 中, 用不锈钢刮刀将4培养皿中的单克隆细菌提取出来, 然后分别放入7管中。</li>
	<li>将7根管子放在37° c 的恒温箱中24小时。</li>
	<li>用视觉比色法选取最大光散射的一个。</li>
</ol>7. 用葡萄糖和盐制备 LB 蓝诺克斯汤
<ol><li>将10克的 LB 蓝诺克斯汤、10克氯化钠和10克葡萄糖放入500毫升的实验室瓶中。加入水, 直到体积达到450毫升。</li>
	<li>搅拌的内容与聚四氟乙烯磁性搅拌棒20分钟。</li>
	<li>高压釜的内容在120° c 为10分钟。</li>
</ol>8. 钨酸钠的制备
<ol><li>将16.5 克钨酸钠 Na2窝4. 2H2O 放入一个100毫升的实验室瓶子, 用不锈钢刮刀。加入水, 直到体积达到50毫升。</li>
	<li>搅拌的内容与聚四氟乙烯磁性搅拌棒20分钟。</li>
	<li>高压釜的内容在120° c 为10分钟。</li>
	<li>在生物安全柜中, 用1µm 孔的真空玻纤过滤器获得滤液。</li>
</ol>9. 用葡萄糖、盐和钨酸钠制备 LB
<ol><li>在生物安全柜中, 将步骤8.4 中的滤液用手倒入步骤7.3 中制备的葡萄糖和盐溶液中。</li>
	<li>在生物安全柜中, 分用吸管将500毫升的溶液在步骤9.1 中转化为 10 x 50 毫升离心管。</li>
</ol>10. 细菌培养
<ol><li>在生物安全柜中, 取出步骤6.4 中准备好的液体, 然后用吸管将其分在步骤9.2 中准备的10试管中, 每根管子接收0.05 毫升。</li>
	<li>孵育10管在一个37° c 孵化器为 120 h。</li>
</ol>11. BME 矿物的收获
<ol><li>Ultrasonicate 10 管在步骤9.2 在20赫与 150 W 为 1 h。</li>
	<li>离心管在 2025 x g 为 1 h。</li>
	<li>用吸管除去管内的透明液体, 再加水, 再重复步骤11.1 和11.2 次。</li>
	<li>用吸管除去管内的透明液体, 加入酒精, 然后在20赫上 ultrasonicate 150 W, 1 小时。</li>
	<li>离心管在 2025 x g 为 1 h。</li>
	<li>重复步骤11.4 和11.5 一次</li>
	<li>用吸管除去管内的透明液体, 收获 BME 矿物;之后, 立即盖上管子而不运行任何干燥过程。</li>
</ol>12. 振荡温度与Pandoraea sp和钼酸盐
<ol><li>区域性Pandoraea sp的方式与步骤2、3、4、5和6中的希瓦藻类相同。此步骤的结果对应于步骤6.4。</li>
	<li>用与步骤7、8和9相同的方法使 LB 肉汤与葡萄糖和盐相同, 但步骤7.1 中钨酸钠的16.5 克被替换为12克钼酸钠, Na2MoO4 ·2H2O。此步骤的结果对应于步骤9.2。</li>
	<li>在生物安全柜中, 取出步骤12.1 中准备好的液体, 然后用吸管将其分在步骤12.2 中准备的10管中, 每个管子接收0.05 毫升。</li>
	<li>孵育10管在步骤12.3 在振荡温度下为 120 h 在一个相互摇晃的浴, 摆动温度5次在25° c 和37° c 之间, 以每温度持久为 12 h。</li>
</ol>

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作者没有什么可透露的。

关于实验结果的自洽性, 单克隆细菌的制备和增殖至关重要。本实验, 不同于模板合成实验的15,16, 采用了生物活性革兰阴性菌。为了获得一个单一的壁, 我们选择了原核细菌, 而不是真核细菌, 如酵母15。为了实现一个直径为1:1 的长径比的球形形状, 而不是更大的长径比16, 我们为细菌提供了更高浓度的 oxyanions, 以使它们能够收缩成球形, 制作微胶囊有一个单一的, 圆的, 薄的墙 (< 30 nm)。
由于 BME 主要依靠调节 oxyanions 的浓度来控制细菌的代谢, 因此具有两个局限性。首先, oxyanions 的浓度受溶解度的限制, 但浓度应尽可能高。其次, 大多数细菌的新陈代谢会在45° c 或5° c 以下的温度下停止, 分别是我们实验的上下限。
尽管这两个限制, BME 有很大的潜力, 使金属氧化物材料的实际利益。为了证实这一说法, 我们将尝试用这种方法制作锆微囊和铁微囊--前者是人造骨骼的良好候选材料, 后者用于药物的传递。

金属氧化物纳米微粒被开发为药物传递1, 构造人工骨骼2, 非均相催化3, 场发射4,5, 太阳能电池6, 气体传感器7, 以及锂电池8。在实际应用中, 纳米晶及其显微结构的力学强度是至关重要的。在微结构中, 空心壳体可用于创建轻质、机械坚固的材料9。在空心壳体结构中, 已知球形形状比椭球形更坚硬;后者具有比前1011更大的长径比。本工作介绍了一种在环境条件下用非毒性方法合成球形微胶囊的协议, 与其他方法 (包括模板合成方法12) 形成了对比,超声波喷雾辅助合成方法13和水热法14。一些替代方法需要模板12, 一些温度高达500° c13, 一些高压14。至于所产生的结构, 采用酵母模板的模板合成方法带来了一个核心壳结构15, 而不是一个单一的墙, 而使用大肠杆菌模板的一个结构产生长径比为 1.7: 0.8, 而不是球形。16。
在这项工作中, 我们利用细菌代谢, 在环境条件下, 用单壁和球形形状制作金属氧化物微胶囊。在细菌酵解中, 代谢碳源的化学过程, 如葡萄糖和乳糖, 碳源被认为是其中产生的还原力的来源。我们通过调节碳源的浓度来控制细菌代谢, 以达到预期的目的。这种方法对环境友好, 使用无毒剂, 耗电量更少。最后, 这种方法可以简单地通过增加肉汤的体积来批量生产微胶囊。
在该方法之前, 还有另外两种利用细菌代谢来制造矿物质的方法: 生物诱导矿化 (比)17和生物控制矿化 ()18。这两种方法都不能用于制备钨酸钠和钨酸盐微胶囊, 如我们的工艺, 被指定为细菌矿物排泄 (BME)19。在这个实验中, 微胶囊的形状可以被控制为有一个长度-直径比从10:1 到 1:1, 和大小的纳米颗粒形成的壳可以调整范围从 15 nm 到 110 nm。

<table><tbody><tr><td>LB(Lennox)broth with agar tablets</td><td>Sigma-Aldrich</td><td>L7075</td><td>1 tablet for 50 mL broth with agar</td></tr><tr><td>LB (Lennox) broth</td><td>Sigma-Aldrich</td><td>L3022-1KG</td><td>LB (Lennox) powder 1 kg</td></tr><tr><td>Dextrose anhydrous</td><td>Nihon Shiyaku Reagent</td><td>PL 78695</td><td>glucose</td></tr><tr><td>Sodium Tungstate</td><td>Nihon Shiyaku Reagent</td><td>PL 76050</td><td>Na&lt;sub&gt;2&lt;/sub&gt;WO&lt;sub&gt;4&lt;/sub&gt; &amp;middot; 2H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>Sodium Molybdate</td><td>Nihon Shiyaku Reagent</td><td>PL103564</td><td>Na&lt;sub&gt;2&lt;/sub&gt;MoO&lt;sub&gt;4&lt;/sub&gt; &amp;middot; 2H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>Sodium Chloride</td><td>Nihon Shiyaku Reagent</td><td>PL 68131</td><td>NaCl</td></tr><tr><td>Ethanol 99.5%</td><td>Acros organics</td><td>AC615090040</td><td>CH&lt;sub&gt;3&lt;/sub&gt;CH&lt;sub&gt;2&lt;/sub&gt;OH</td></tr><tr><td>Water</td><td>Made in our university</td><td></td><td>de-ionlized water</td></tr><tr><td>Autoclave</td><td>Tomin Medical Equipmenco, Ltd., Taipei City, Taiwan, ROC</td><td>TM-329</td><td>heat to 120 &amp;deg;C for 10 min</td></tr><tr><td>Centrifuge</td><td>Digit System Laboratory System, New Taipei City, Taiwan, ROC</td><td>DSC302SD</td><td>centrifuge at 2025 x g</td></tr><tr><td>-80 &amp;deg;C Refrigerator</td><td>Panasonic</td><td>MDF-U3386S</td><td>Use to deep-freeze cryopreserve strain</td></tr><tr><td>Ultrasonic Homogenizer Sonicator Processor Cell Disruptor</td><td>Lenox</td><td>UPS-150</td><td>frequency 20 KHz power 150 W</td></tr><tr><td>Incubator</td><td>Customer made</td><td>custom made</td><td>heat to 40 &amp;deg;C or cool to 18 &amp;deg;C with time cotrol</td></tr><tr><td>Reciprocal shaking baths</td><td>Kingtech Scientific Co., Ltd</td><td>WBS-L</td><td></td></tr><tr><td>Digital Stirring Hot Plate</td><td>Corning</td><td>#6797-620D</td><td>use with PTFE magnetic stirring bar</td></tr><tr><td>Biosafety cabinet</td><td>Zong Yen co., LTD</td><td>ZYBH-420</td><td>All bacteria related process are done here</td></tr><tr><td>Scanning electron microscope</td><td>JEOL</td><td>JSM-6500F</td><td>SEM Images</td></tr><tr><td>50 mL centrifudge tube</td><td>Falcon</td><td>14-432-22</td><td></td></tr><tr><td>15 mL centrifudge tube</td><td>Falcon</td><td>14-959-53A</td><td></td></tr><tr><td>Laboratory bottle 100 mL</td><td>Duran</td><td>21 801 24 5</td><td></td></tr><tr><td>Laboratory bottle 500 mL</td><td>Duran</td><td>21 801 44 5</td><td></td></tr><tr><td>Stainless steel spatula</td><td>Chemglass</td><td>CG-1981-10</td><td></td></tr><tr><td>PTFE Disposable Stir Bars</td><td>Fisher</td><td>S68066</td><td></td></tr><tr><td>Plastic Petri Dishes</td><td>Fisher</td><td>S33580A</td><td></td></tr><tr><td>Shewanella algae</td><td>Courtesy of author #3</td><td>Courtesy of author #3</td><td></td></tr><tr><td>Pandoraea sp.</td><td>Courtesy of author #3</td><td>Courtesy of author #3</td><td></td></tr></tbody></table>

synthesizing sodium tungstate and sodium molybdate microcapsules via bacterial mineral excretion

我们提出了一种方法, 细菌矿物排泄 (BME), 合成两种微胶囊, 钨酸钠和钼酸钠, 和两个金属氧化物的相应纳米粒子-前者是小到22纳米和后者 15 nm。我们喂养了两株细菌,希瓦藻类和Pandoraea sp., 各种浓度的钨酸盐或钼酸离子。对钨酸和钼酸盐的浓度进行了调整, 使微胶囊的长度和直径比不同。我们发现, 浓度越高, 纳米粒子越小。纳米颗粒以三的长径比: 10:1、3:1 和 1:1, 分别以低浓度、中等浓度和高浓度的细菌为食。采用扫描电子微球 (SEM) 对空心微胶囊进行了图像分析。通过 x-射线衍射 (XRD) 验证了晶体结构, 钼酸盐微胶囊的晶体结构为 na2MoO4 , 钨酸微胶囊为 na2窝4与 na2W2O7。这些合成都是在近环境条件下完成的。

图 1显示了真正的球形微胶囊。两株细菌,希瓦藻和Pandoraea sp, 原来都有长度-直径比3:1。为了达到1:1 的长径比, 需要高浓度 (> 100 mM) 的金属 oxyanions。低浓度 (< 5 毫米) 的 oxyanions 可以导致长度到直径比 10:1, 因为那在图 2, 这可能是由于涌入的 oxyanions, 阻断了二元裂变细菌。最后, 为了实现长径比为 3:1, 如图 3所示, 需要一个中等浓度 (约 20 mM) 的 oxyanions。球壳的形成, 长度与直径比为 1:1, 可能是由细菌驱动, 使自己收缩其表面积, 以平衡 oxyanions 的摄入, 同时扩散 oxyanions 通过细胞膜。三的数字显示, 长径比可以通过调整 oxyanions 的浓度来调节到10:1 到1:1。
图 4和图 5显示了不同大小的钼酸钠颗粒: 较小的是 15 nm, 更大的一个 110 nm。请注意, 在图 5中, 在未被粉碎的壳体上, 110 nm 的粒子仍然可以相互链接, 形成多孔壳。更大的一个是通过摆动发酵液的温度5次在25° c 和37° c 之间, 以每温度持续为 12 h。在温度振荡过程中, 不仅可以生产不同尺寸的晶粒, 还能保持微球形结构, 这就意味着我们可以通过控制肉汤的温度, 使不同粒度的微胶囊从 15 nm 到 110 nm。.
图 6显示了在墙的开口旁边有较大颗粒的破墙。壁厚约 22 nm, 较大的颗粒约 40-60 nm。不同的新陈代谢过程可能会导致大小的差异, 而这还没有被确定。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57022/57022fig1.jpg"> 图 1: 具有长径比为1:1 的空心球形壳的 SEM 图像.这种结构是由以葡萄糖为碳源的希瓦藻排出的钨酸钠。经《固体科学与技术》、6 (3)、N3113 (2017) 的许可, 转载。版权所有 2017, 电化学学会。<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57022/57022fig2.jpg"> 图 2: 长度-直径比为10:1 的空心长丝壳的 SEM 图像.该结构是由以葡萄糖为碳源的Pandoraea sp排出的钼酸钠。经《固体科学与技术》、6 (3)、N3113 (2017) 的许可, 转载。版权所有 2017, 电化学学会。<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig2large.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/57022/57022fig3.jpg"> 图 3: 具有长度-直径比为3:1 的空心杆形壳体的 SEM 图像.这种结构是由以葡萄糖为碳源的希瓦藻排出的钨酸钠。经《固体科学与技术》、6 (3)、N3113 (2017) 的许可, 转载。版权所有 2017, 电化学学会。<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57022/57022fig4.jpg"> 图 4: 被粉碎的钼酸钠壳的 SEM 图像, 粒度为 15 nm.<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig4large.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/57022/57022fig5.jpg"> 图 5: 被粉碎和非粉碎的钼酸钠壳的 SEM 图像, 粒度为 110 nm.<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/57022/57022fig6.jpg"> 图 6: 具有长度-直径比为1:1 的破空心壳的 SEM 图像.这种结构是由以葡萄糖为碳源的希瓦藻排出的钨酸钠。大小约 40-60 nm 的颗粒悬挂在壳体的旁边的一个大洞, 而外壳本身是由颗粒的大小约 22 nm。经《固体科学与技术》、6 (3)、N3113 (2017) 的许可, 转载。版权所有 2017, 电化学学会。<a href="//cloudflare.jove.com/files/ftp_upload/57022/57022fig6large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion at JoVE.com

Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion

本工作提出了一种通过细菌及其相应的纳米粒子制备钨酸钠和钼酸钠微胶囊的协议。

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 ...

synthesizing-sodium-tungstate-sodium-molybdate-microcapsules-via

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

8.5K 次观看.  National Taiwan University of Science and Technology. 本工作提出了一种通过细菌及其相应的纳米粒子制备钨酸钠和钼酸钠微胶囊的协议。

视频: Synthesizing Sodium Tungstate and Sodium Molybdate Microcapsules via Bacterial Mineral Excretion

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

单金属和双金属前过渡金属碳化物和氮化物纳米粒子的反相微乳液介导的合成

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

科研

化学

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

纳米尺寸钛酸二氢钠的合成和化学反应

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature solvents. These coordinating ligands help solubilize and stabilize the nanoparticles while in solution, and can influence the resulting size and reactivity of the nanoparticles during their formation. Despite the ubiquity of using ligands during synthesis, the presence of aliphatic ligands on the nanoparticle surface can result in a number of problems during the end use of the nanoparticles, necessitating further ligand stripping or ligand exchange procedures. We have developed a way to synthesize cadmium sulfide (CdS) nanoparticles using a unique sulfur copolymer. This sulfur copolymer is primarily composed of elemental sulfur, which is a cheap and abundant material. The sulfur copolymer has the advantages of operating both as a high temperature solvent and as a sulfur source, which can react with a cadmium precursor during nanoparticle synthesis, resulting in the generation of ligand free CdS. During the reaction, only some of the copolymer is consumed to produce CdS, while the rest remains in the polymeric state, thereby producing a nanocomposite material. Once the reaction is finished, the copolymer stabilizes the nanoparticles within a solid polymeric matrix. The copolymer can then be removed before the nanoparticles are used, which produces nanoparticles that do not have organic coordinating ligands. This nascent synthesis technique presents a method to produce metal-sulfide nanoparticles for a wide variety of applications where the presence of organic ligands is not desired.

Herein we present a method to synthesize ligand-free cadmium sulfide (CdS) nanoparticles based on a unique sulfur copolymer. The sulfur copolymer operates as a high temperature solvent and a sulfur source during the nanoparticle synthesis and stabilizes the nanoparticles after the reaction.

a硫磺共聚物基质内的免费配体硫化镉纳米粒子的合成

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

Nanosponge Tunability in Size and Crosslinking Density

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with controlled dimensions. This approach begins with synthesis of a functionalized lactone which is key to the pendant functionalization of the resulting polymer. Valerolactone (VL) and allyl-valerolactone (AVL) are then copolymerized using ring-opening polymerization. Post-polymerization modification is then used to install an epoxide moiety on some or all of the pendant allyl groups. Epoxy-amine chemistry is employed to form nanoparticles in a dilute solution of both polymer and small molecule diamine crosslinker based on the desired nanosponge size and crosslinking density. Nanosponge sizes can be characterized by transmission electron microscopy (TEM) imaging to determine the dimension and distribution. This method provides a pathway by which highly tunable polyesters can create tunable nanoparticles, which can be used for small molecule drug encapsulation. Due to the nature of the backbone, these particles are hydrolytically and enzymatically degradable for a controlled release of a wide range of hydrophobic small molecules.

This article describes a process for tuning the size and crosslinking density of covalently crosslinked nanoparticles from linear polyesters containing pendant functionality. By tailoring synthesis parameters (polymer molecular weight, pendant functionality incorporation, and crosslinker equivalents), a desired nanoparticle size and crosslinking density can be achieved for drug delivery applications.

Nanosponge 可调大小和交联密度

We describe a protocol for the synthesis of linear polyesters containing pendant epoxide functionality and their incorporation into a nanosponge with ...

Analysis of Minerals Produced by hFOB 1.19 and Saos-2 Cells Using Transmission Electron Microscopy with Energy Dispersive X-ray Microanalysis

This video presents the use of transmission electron microscopy with energy dispersive X-ray microanalysis (TEM-EDX) to compare the state of minerals in vesicles released by two human bone cell lines: hFOB 1.19 and Saos-2. These cell lines, after treatment with ascorbic acid (AA) and &#946;-glycerophosphate (&#946;-GP), undergo complete osteogenic transdifferentiation from proliferation to mineralization and produce matrix vesicles (MVs) that trigger apatite nucleation in the extracellular matrix (ECM).
Based on Alizarin Red-S (AR-S) staining and analysis of the composition of minerals in cell lysates using ultraviolet (UV) light or in vesicles using TEM imaging followed by EDX quantitation and ion mapping, we can infer that osteosarcoma Saos-2 and osteoblastic hFOB 1.19 cells reveal distinct mineralization profiles. Saos-2 cells mineralize more efficiently than hFOB 1.19 cells and produce larger mineral deposits that are not visible under UV light but are similar to hydroxyapatite (HA) in that they have more Ca and F substitutions.
The results obtained using these techniques allow us to conclude that the process of mineralization differs depending on the cell type. We propose that, at the cellular level, the origin and properties of vesicles predetermine the type of minerals.

We present a protocol to compare the state of minerals in vesicles released by two human bone cell lines: hFOB 1.19 and Saos-2. Their mineralization profiles were analyzed by Alizarin Red-S (AR-S) staining, ultraviolet (UV) light visualization, transmission electron microscopy (TEM) imaging and energy dispersive X-ray microanalysis (EDX).

透射电镜 hFOB 1.19 和 Saos-2 细胞产生的能量色散 X 射线显微分析

This video presents the use of transmission electron microscopy with energy dispersive X-ray microanalysis (TEM-EDX) to compare the state of minerals in ...

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. Here, we introduce the molten-salt synthesis (MSS) method for making metal oxide nanomaterials. Advantages over other methods include its simplicity, greenness, reliability, scalability, and generalizability. Using pyrochlore lanthanum hafnium oxide (La2Hf2O7) as a representative, we describe the MSS protocol for the successful synthesis of complex metal oxide nanoparticles (NPs). Furthermore, this method has the unique ability to produce NPs with different material features by changing various synthesis parameters such as pH, temperature, duration, and post-annealing. By fine-tuning these parameters, we are able to synthesize highly uniform, non-agglomerated, and highly crystalline NPs. As a specific example, we vary the particle size of the La2Hf2O7&#160;NPs by changing the concentration of the ammonium hydroxide solution used in the MSS process, which allows us to further explore the effect of particle size on various properties. It is expected that the MSS method will become a more popular synthesis method for nanomaterials and more widely employed in the nanoscience and nanotechnology community in the upcoming years.

Here, we demonstrate a unique, relatively low-temperature, molten-salt synthesis method for preparing uniform complex metal oxide lanthanum hafnate nanoparticles.

复合金属氧化物纳米粒子的熔融盐合成

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. ...

Extraction of Plant-based Capsules for Microencapsulation Applications

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin exine capsules (SECs) are obtained when spores or pollen are processed so as to remove the internal sporoplasmic contents. The resulting hollow microcapsules exhibit a high degree of micromeritic uniformity and retain intricate microstructural features related to the particular plant species. Herein, we demonstrate a streamlined process for the production of SECs from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs. The current SEC isolation procedure has been recently optimized to significantly reduce the processing requirements which are conventionally used in SEC isolation, and to ensure the production of intact microcapsules. Natural L. clavatum spores are defatted with acetone, treated with phosphoric acid, and extensively washed to remove sporoplasmic contents. After acetone defatting, a single processing step using 85% phosphoric acid has been shown to remove all sporoplasmic contents. By limiting the acid processing time to 30 hr, it is possible to isolate clean SECs and avoid SEC fracturing, which has been shown to occur with prolonged processing time. Extensive washing with water, dilute acids, dilute bases, and solvents ensures that all sporoplasmic material and chemical residues are adequately removed. The vacuum loading technique is utilized to load a model protein (Bovine Serum Albumin) as a representative hydrophilic compound. Vacuum loading provides a simple technique to load various compounds without the need for harsh solvents or undesirable chemicals which are often required in other microencapsulation protocols. Based on these isolation and loading protocols, SECs provide a promising material for use in a diverse range of microencapsulation applications, such as, therapeutics, foods, cosmetics, and personal care products.

This protocol/manuscript describes a streamlined process for the production of sporopollenin exine capsules (SECs) from Lycopodium clavatum spores and for the loading of hydrophilic compounds into these SECs.

基于植物的提取胶囊微胶囊化应用

Microcapsules derived from plant-based spores or pollen provide a robust platform for a diverse range of microencapsulation applications. Sporopollenin ...

生物工程

Triplet Fusion Upconversion Nanocapsule Synthesis

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has significant implications for producing high energy light beyond a material's surface. However, the deployment of UC materials has been stymied due to poor material solubility, high concentration requirements, and oxygen sensitivity, ultimately resulting in reduced light output. Toward this end, nanoencapsulation has been a popular motif to circumvent these challenges, but durability has remained elusive in organic solvents. Recently, a nanoencapsulation technique was engineered to tackle each of these challenges, whereupon an oleic acid nanodroplet containing upconversion materials was encapsulated with a silica shell. Ultimately, these nanocapsules (NCs) were durable enough to enable triplet fusion upconversion-facilitated volumetric three-dimensional (3D) printing. By encapsulating upconversion materials with silica and dispersing them in a 3D printing resin, photopatterning beyond the surface of the printing vat was made possible. Here, video protocols for the synthesis of upconversion NCs are presented for both small-scale and large-scale batches. The outlined protocols serve as a starting point for adapting this encapsulation scheme to multiple upconversion schemes for use in volumetric 3D printing applications.

This protocol details the synthesis of upconversion nanocapsules for subsequent use in photopolymerizable resins for triplet fusion upconversion-facilitated volumetric 3D printing.

三重融合上转换纳米胶囊合成

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has ...

工程学

Synthesis of Black Seed Oil-loaded-, Alginate-based, pH-sensitive Beads Using Electrospraying Technique

Black seed oil (BSO), derived from the seeds of the Nigella sativa plant, has garnered attention for its potential anti-cancer properties, particularly in the context of colon cancer. Its active compound, thymoquinone, may help inhibit cancer cell growth and induce apoptosis in colon cancer cells. Additionally, black seed oil's anti-inflammatory and antioxidant effects could contribute to a healthier gut environment, potentially reducing cancer risk. Therefore, this study synthesized pH-sensitive alginate beads to deliver BSO into the colon in a controlled-release manner without releasing the drug at pH 1.2 (stomach), thus providing a well-defined release pattern at pH 6.8. The use of electrospray technology improves process performance by making it easier to formulate small, homogeneous beads with a higher rate of swelling and diffusion in the gastrointestinal medium. 
The formulated beads were characterized by an ex-vivo mucoadhesive strength test, bead size, sphericity factor (SF), encapsulation efficiency (EE), scanning electron microscope (SEM), in vitro swelling behavior (SB), and in vitro drug release in acidic and buffer media. All these manufactured beads demonstrated modest sizes of 0.58 &plusmn; 0.01 mm and spherical shape of 0.03 &plusmn; 0.00 mm in this testing. The formulation showed promising floating and releasing properties in vitro. With a very low cumulative percentage of beads, the oil EE of 90.13% &plusmn; 0.93% was high, and the release study demonstrated more than 90% in pH 6.8 with good floating nature in the stomach. Additionally, the beads were evenly spaced throughout the intestine. The electrospraying approach used in this protocol can be reproducible, yielding consistent outcomes. Therefore, this protocol can be used for large-scale production for commercialization purposes.

A technique employing high electric voltage and a targeted, active ingredient-loaded emulsion to fabricate pH-responsive, uniform microbeads is presented.

Black seed oil (BSO), derived from the seeds of the Nigella sativa plant, has garnered attention for its potential anti-cancer properties, particularly in ...

Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of Manganese(II) Acetylacetonate

For biomedical applications, metal oxide nanoparticles such as iron oxide and manganese oxide (MnO), have been used as biosensors and contrast agents in magnetic resonance imaging (MRI). While iron oxide nanoparticles provide constant negative contrast on MRI over typical experimental timeframes, MnO generates switchable positive contrast on MRI through dissolution of MnO to Mn2+ at low pH within cell endosomes to &#8216;turn ON&#8217; MRI contrast. This protocol describes a one-pot synthesis of MnO nanoparticles formed by thermal decomposition of manganese(II) acetylacetonate in oleylamine and dibenzyl ether. Although running the synthesis of MnO nanoparticles is simple, the initial experimental setup can be difficult to reproduce if detailed instructions are not provided. Thus, the glassware and tubing assembly is first thoroughly described to allow other investigators to easily reproduce the setup. The synthesis method incorporates a temperature controller to achieve automated and precise manipulation of the desired temperature profile, which will impact resulting nanoparticle size and chemistry. The thermal decomposition protocol can be readily adapted to generate other metal oxide nanoparticles (e.g., iron oxide) and to include alternative organic solvents and stabilizers (e.g., oleic acid). In addition, the ratio of organic solvent to stabilizer can be changed to further impact nanoparticle properties, which is shown herein. Synthesized MnO nanoparticles are characterized for morphology, size, bulk composition, and surface composition through transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy, respectively. The MnO nanoparticles synthesized by this method will be hydrophobic and must be further manipulated through ligand exchange, polymeric encapsulation, or lipid capping to incorporate hydrophilic groups for interaction with biological fluids and tissues.

Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate

This protocol details a facile, one-pot synthesis of manganese oxide (MnO) nanoparticles by thermal decomposition of manganese(II) acetylacetonate in the presence of oleylamine and dibenzyl ether. MnO nanoparticles have been utilized in diverse applications including magnetic resonance imaging, biosensing, catalysis, batteries, and waste water treatment.

锰氧化物纳米粒子合成锰（II）乙酰酸盐的热分解

For biomedical applications, metal oxide nanoparticles such as iron oxide and manganese oxide (MnO), have been used as biosensors and contrast agents in ...