This research was supported by the "Development of technologies for safety evaluation and standardization of nanomaterials and nanoproducts" (10059135)" through the Korea Evaluation Institute of Industrial Technology by the Korean Ministry of Trade, Industry &amp; Energy.

1.仪器和样品的制备<ol><li> Abrasor <ol><li>基于磨耗试验机，使用一个abrasor与一种样品旋转台（140毫米直径），两个磨轮支架，和30的旋转速度 - 80转。 </li><li>使用权重的磨损轮固定在磨损轮夹持，这也适用于负载的试样。 </li><li>安装一个额外的空气入口为abrased颗粒提供较好的悬浮， 如图3。使用1/8" -直径管仅有15毫米的位置和40 mm的试验片的中心距离。 </li></ol></li><li> 砂轮 <ol><li>包裹砂轮（直径55毫米13毫米厚）用砂纸（100砂砾和全新的）。 </li></ol></li><li> 标本 <ol><li>样品是包含磨耗试验纳米材料的复合材料。要安装在abrasor，试样应该准备机智ħ140毫米直径。 </li></ol></li><li> 房间 <ol><li>使用不锈钢室壁以避免由于静电力颗粒沉积。放置所述腔室（体积1米3）（ 表1）内的abrasor，并分别定位在腔室的上部和下部的空气入口和出口。使用混合器，由三个多孔板，在空气出口处实现了均匀混合的颗粒流。 </li></ol></li><li> 中和剂 <ol><li>作为静电的颗粒提高在室壁上颗粒沉积，使用的中和剂（软X射线离子发生器），以最大限度地减少颗粒的带电状态。 </li></ol></li><li> 在线测量仪器12，13 <ol><li>使用单次点击和OPC来测量粒子个数浓度和粒度分布按照制造商的说明。 </li><li>安装在outle党和OPC腔室的吨至测量颗粒个数浓度及粒径分布。 </li></ol></li><li> 粒子采样仪器 <ol><li>样品使用含粒子取样的过滤介质或TEM网格来分析颗粒形态和成分的释放的粒子。 </li><li>在腔室的出口处安装含粒子取样的过滤介质或TEM网格来分析释放颗粒的形态。 </li></ol></li></ol>使用室系统2.磨损试验的纳米粒子释放注:磨损试验条件在表2中描述。 <ol><li>定位在腔室的中心abrasor。 </li><li>在abrasor的试样旋转阶段安装试验片。 </li><li>固定在磨轮支架的磨损轮与千克体重施加负载到测试样品。 </li><li>找到中和剂（软X射线离子发生器）28厘米从试样在45°角的中心距离，如在图2中看到的，为了减少在室壁上的静电颗粒沉积。 注:中和剂删除由束曝光的静电力。然而，由于进气口和磨损轮上方的样品旋转台，这限制了中和剂束到测试样品表面的访问。因此，在中和器位于斜，以允许光束到达尽可能多的试样表面尽可能的。 </li><li>操作安装在腔室的出口的鼓风机以50升/分钟的流速。 </li><li>供给25升/分钟，用空气压缩机通过附加空气入口附加无颗粒的悬浮液的空气。 注:颗粒，这是由摩擦而产生的，沉积在试样和磨损轮的表面上，强烈。因此，很难以测量abrased颗粒。额外的进气口可以HELp来解决这个问题，以粒子悬浮液。 </li><li>检查背景颗粒数浓度腔室内部达到的平均颗粒数浓度使用中共低于1＃/立方厘米1小时，如在图4中描述。 </li><li>操作使用的步进马达，在每分钟72与1000转旋转试样旋转阶段abrasor的检体旋转的阶段。 </li><li>测量并记录使用党和OPC释放的粒子数浓度和粒径分布。 注意:从纳米复合材料释放的颗粒悬浮和通过正被泵送的空气中进行。这些悬浮颗粒最终被输送到气流以下的出口。被释放的颗粒然后由中共和OPC在腔室的出口处检测到。每次点击成本和OPC最常用于测量粒子个数浓度，而一个OPC还可以测量粒径分布。 </li><li>桑普乐使用含有过滤介质或TEM网格上的粒子采样器释放粒子。 注:因磨损举动从纳米复合材料释放到腔室的气流以下出口处的颗粒。在腔室的出口，被释放的颗粒可以使用粒子采样进行采样。收集在过滤介质或TEM网格释放粒子然后可以用TEM或SEM（扫描电子显微镜）分析。 </li><li>停止测量和取样时，下面的粒子个数浓度达到峰值粒子个数浓度为0.1％。 </li><li>保存所有数据（CPC，OPC），并删除所有样品（样品）。 </li><li>使用一个新的样品和新磨损轮为每个测试，和洗涤腔室和各磨损试验后的Kimwipes和IPA（异丙醇）abrasor确认重复性。 </li></ol>

<ol>
	<li>Froggett, S. J., Clancy, S. F., Boverhof, D. R., Canady, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+and+perspectives+of+existing+research+on+the+release+of+nanomaterials+from+solid+nanocomposites.">A review and perspectives of existing research on the release of nanomaterials from solid nanocomposites.</a> Part Fibre Toxicol. 11, (2014).</li><li>Kingston, C., Zepp, R., Andrady, A., Boverhof, D., Fehir, R., Hawkins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Release+characteristics+of+selected+carbon+nanotube+polymer+composites.">Release characteristics of selected carbon nanotube polymer composites.</a> Carbon. 68, 33-57 (2014).</li><li>Kaiser, D., Stefaniak, A., Scott, K., Nguyen, T., Schutz, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods for the Measurement of Release of MWCNTs from MWCNT-Polymer Composites, NIST. , (2014).</li><li>Nowack, B., David, R. M., Fissan, H., Morris, H., Shatkin, J. A., Stintz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potential+release+scenarios+for+carbon+nanotubes+used+in+composites.">Potential release scenarios for carbon nanotubes used in composites.</a> Environ. Int. 59, 1-11 (2013).</li><li>Kim, E., Lee, J. H., Kim, J. K., Lee, G. H., Ahn, K., Park, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Case+Study+on+Risk+Evaluation+of+Silver+Nanoparticle+Exposure+from+Antibacterial+Sprays+Containing+Silver+Nanoparticles.">Case Study on Risk Evaluation of Silver Nanoparticle Exposure from Antibacterial Sprays Containing Silver Nanoparticles.</a> J of Nanomaterial. , 346586 (2015).</li><li>Kim, E., Lee, J. H., Kim, J. K., Lee, G. H., Ahn, K., Park, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Case+study+on+risk+evaluation+of+printed+electronics+using+nanosilver+ink.">Case study on risk evaluation of printed electronics using nanosilver ink.</a> Nano Convergence. , (2016).</li><li>Vorbau, M., Hillemann, L., Stintz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+for+the+characterization+of+the+abrasion+induced+nanoparticle+release+into+air+from+surface+coatings.">Method for the characterization of the abrasion induced nanoparticle release into air from surface coatings.</a> J. Aerosol Sci. 40, 209-217 (2009).</li><li>Golanski, L., Gaborieau, A., Guiot, A., Uzu, G., Chatenet, J., Tardif, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+abrasion-induced+nanoparticle+release+from+paints+into+liquids+and+air.">Characterization of abrasion-induced nanoparticle release from paints into liquids and air.</a> J. Phys. Conf. Ser. 304, 012062 (2011).</li><li>Wohlleben, W., Brill, S., Meier, M. W., Mertler, M., Cox, G., Hirth, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+lifecycle+of+nanocomposites:+Comparing+released+fragments+and+their+in-vivo+hazards+from+three+release+mechanisms+and+four+nanocomposites.">On the lifecycle of nanocomposites: Comparing released fragments and their in-vivo hazards from three release mechanisms and four nanocomposites.</a> Small. 7, 2384-2395 (2011).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> ISO 7784-1, Paints and varnishes -- Determination of resistance to abrasion -- Part 1: Rotating abrasive-paper-covered wheel method. , (1997).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> ISO 5470-1, Rubber- or plastics-coated fabrics -- Determination of abrasion resistance -- Part 1: Taber abrader. , (1999).</li><li>Schlagenhauf, L., Chu, B. 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The authors have nothing to disclose.

使用的磨损试验进行从纳米复合材料nanorelease测试时最重要的步骤是:1使用具有中和剂由不锈钢制成的腔室系统以除去因磨损所产生的静电荷，并减少在室壁上的颗粒的沉积）; 2）提供额外的空气以提供更好的颗粒悬浮液; 3）抽样利用包含由三个多孔板的混频器出口的中国共产党和OPC释放粒子和在线监测。 耐磨测试仪最初设计基于ISO 7784-1或ISO 5470-1 14-15评估耐磨性。耐...

纳米材料的曝光大多被研究有关工人工作场所制造，处理，制造，包装纳米材料，而消费者接触还没有被广泛研究。通过纳米技术国际理事会（ICON）创造了环境和健康文献数据库的最近的分析也表明，大多数纳米材料安全性研究都集中在危害（83％）和潜在风险（16％），与纳米复合材料的发布，代表消费者接触，仅相当于0.8％1。因此，很少有人知道有关消费者接触纳米材料。 纳米颗粒释放已被用来估计在模拟研究，包括磨损，纳米复合材料，洗涤纺织品，或含尘测试方法，如旋转鼓的方法，涡流振荡方法以及其它摇床方法2-3的风化消费者接触。此外，一些国际尝试，如ILSI（国际生命科学研究所）nanorelease和欧盟NanoReg，已经进行了技术开发，以了解在消费产品中使用的纳米材料的释放。于2011年推出的ILSI nanorelease消费产品代表了生命周期方法，从消费类产品，其中第一阶段涉及纳米材料的选择纳米材料的释放，第二阶段涵盖的评价方法，以及第3阶段实施间研究。在消费类产品纳米材料的安全性几个专着和出版物也已出版了4-6。 同时，NanoReg代表欧洲共同的方法来制造纳米材料的法规测试，并提供了在使用模拟方法的程序方法，从消费产品到nanorelease 2. ISO TC 229还试图制定有关消费者的安全标准，并提交新工作项目建议为消费者的安全。经合组织WPMN（worki纳克纳米材料派对），特别是SG8（督导组暴露评估和暴露减缓），最近在今后的工作，尤其是消费者和环境暴露评估的方向进行了调查。因此，在这些国际活动的光，贸易，工业和能源部韩国部委发起于2013年的分层项目主要集中在了"纳米材料和纳米产品的安全性评价和标准化的技术发展。"此外，一些消费者安全相关的研究，以规范从消费产品的纳米材料的释放也已出版了7-8。 磨损试验是包括在ILSI nanorelease和NanoReg 2-3用于确定从不同的商业复合产品纳米颗粒的电势发射电平的模拟方法之一。质量重量损失推导基于之前和阿巴拉后在试样重量差离子使用abrasor。所述纳米复合材料样品以恒定的速度磨损，采样吸收了气溶胶，然后将颗粒用粒子计数装置，如一个冷凝粒子计数器（CPC）或光学粒子计数器（OPC）进行分析，并收集在TEM （透射电子显微镜）网格或膜，用于进一步的视觉分析。然而，进行了纳米复合物材料的磨损试验需要一致的纳米颗粒的释放，这是困难的，因为颗粒充电作为磨损的结果，并当粒子采样发光点2-3，9-11邻近进行。 因此，本文提出了一种腔系统，作为纳米复合材料的磨损情况评估纳米材料释放的新方法。当与其它磨损和模拟测试相比，该室系统提供了在磨损的情况下一致纳米粒子释放的数据。此外，这种新的测试方法已在室内空气质量和半行为行业占总粒子数的计数方法的领域广泛使用的12，13，因此，可以预见，该方法可被开发成用于从含有消费品测试纳米粒子释放的标准化方法纳米材料。

<table><tbody><tr><td>Foamex</td><td>Taeyoung, R. of Korea</td><td></td><td></td></tr><tr><td>MWCNT (multiwalled carbon nanotube) composite</td><td>Hanwha, Incheon, R. of Korea</td><td></td><td>2% MWCNTs in low density polyethylene</td></tr><tr><td>Abrasion Paper</td><td>Derfos, R. of Korea</td><td>#100</td><td>100 grit sand paper</td></tr><tr><td>Condensation Particle Counter (CPC)</td><td>TSI Inc, Shoreview, MN</td><td>UCPC 3775</td><td></td></tr><tr><td>Optical Paritcle Counter (OPC)</td><td>Grimm, Ainring, Germany</td><td>1.109</td><td></td></tr><tr><td>Mini Particle Sampler</td><td>Ecomesure, Saclay, France</td><td></td><td></td></tr><tr><td>Quantifoil Holey Carbon Film</td><td>TED PELLA Inc. USA</td><td>1.2/1.3</td><td></td></tr><tr><td>Filter Holder</td><td></td><td></td><td>custom made</td></tr><tr><td>Polycarbonate Filter&amp;nbsp;</td><td>Millipore, USA</td><td>CAT No. GTTP02500</td><td></td></tr><tr><td>Soft X-ray Ionizer (Neutralizer)</td><td>SUNJE, R. of Korea</td><td>SXN-05U</td><td></td></tr><tr><td>Field Emission-Scanning Electron Microscope (FE-SEM)</td><td>Hitachi</td><td>S-4300</td><td></td></tr></tbody></table>

testing of nanoparticle release from a composite containing nanomaterial using a chamber system

随着纳米技术作为在 21世纪最重要的技术之一的迅速发展，在含有纳米材料的消费品的安全利益也越来越多。从评估含有纳米材料的产品的纳米材料释放在评估这些产品的安全性的关键一步，并导致一些国际努力，以建立一致的，可靠的技术，为规范纳米材料释放的评价。在这项研究中，从含有纳米材料的制品纳米材料的释放，使用的腔室系统，其包括缩合粒子计数器，光学粒子计数器，和取样口，以收集电子显微镜分析滤波器样品进行评价。所提出的腔室系统是使用abrasor和圆盘型纳米复合材料样品以确定所述纳米材料释放是否是在可接受的范围内可重复和一致的测试。测试结果表明，颗粒在每个测试的总数是从平均20％的范围内经过多次试验。流行趋势的发布是相似的，它们显示出非常良好的重复性。因此，所提出的腔室系统可有效地用于含纳米材料的纳米材料的产品释放测试。

磨损试验重复性使用室系统总颗粒数分别为8磨损试验相一致，如表3所示。中共测定3.67×10 9个粒子的平均值，而在OPC计数1.98×10 9颗粒（&gt; 0.3微米）的平均。的偏差为20％，这表示磨损期间颗粒的一致释放内。 Nanorelease从纳米复合材料<p class="jove_content" f...

Watch this Scientific Journal Video about Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System at JoVE.com

Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System

Nanoparticle release is tested using a chamber system that includes a condensation particle counter, an optical particle counter and sampling ports to collect filter samples for microscopy analysis. The proposed chamber system can be effectively used for nanomaterial release testing with a repeatable and consistent data range.

从使用室系统一个复合含纳米材料的纳米颗粒释放测试

With the rapid development of nanotechnology as one of the most important technologies in the 21st century, interest in the safety of consumer products ...

testing-nanoparticle-release-from-composite-containing-nanomaterial

Universidad San Sebastian

Research

JoVE Journal

Engineering

6.7K 次观看.  Hanyang University. Nanoparticle release is tested using a chamber system that includes a condensation particle counter, an optical particle counter and sampling ports to collect filter samples for microscopy analysis. The proposed chamber system can be effectively used for nanomaterial release testing with a repeatable and consistent data range.

视频: Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System

Optical Trapping of Nanoparticles

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping and manipulating small biological particles. Ashkin and co-workers first demonstrated optical tweezers using a single focused beam1. The single beam trap can be described accurately using the perturbative gradient force formulation in the case of small Rayleigh regime particles1. In the perturbative regime, the optical power required for trapping a particle scales as the inverse fourth power of the particle size. High optical powers can damage dielectric particles and cause heating. For instance, trapped latex spheres of 109 nm in diameter were destroyed by a 15 mW beam in 25 sec1, which has serious implications for biological matter2,3.
A self-induced back-action (SIBA) optical trapping was proposed to trap 50 nm polystyrene spheres in the non-perturbative regime4. In a non-perturbative regime, even a small particle with little permittivity contrast to the background can influence significantly the ambient electromagnetic field and induce a large optical force. As a particle enters an illuminated aperture, light transmission increases dramatically because of dielectric loading. If the particle attempts to leave the aperture, decreased transmission causes a change in momentum outwards from the hole and, by Newton's Third Law, results in a force on the particle inwards into the hole, trapping the particle. The light transmission can be monitored; hence, the trap can become a sensor. The SIBA trapping technique can be further improved by using a double-nanohole structure.
The double-nanohole structure has been shown to give a strong local field enhancement5,6. Between the two sharp tips of the double-nanohole, a small particle can cause a large change in optical transmission, thereby inducing a large optical force. As a result, smaller nanoparticles can be trapped, such as 12 nm silicate spheres7 and 3.4 nm hydrodynamic radius bovine serum albumin proteins8. In this work, the experimental configuration used for nanoparticle trapping is outlined. First, we detail the assembly of the trapping setup which is based on a Thorlabs Optical Tweezer Kit. Next, we explain the nanofabrication procedure of the double-nanohole in a metal film, the fabrication of the microfluidic chamber and the sample preparation. Finally, we detail the data acquisition procedure and provide typical results for trapping 20 nm polystyrene nanospheres.

The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.

纳米粒子的光学捕获

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping ...

科研

工程学

Combinatorial Synthesis of and High-throughput Protein Release from Polymer Film and Nanoparticle Libraries

Polyanhydrides are a class of biomaterials with excellent biocompatibility and drug delivery capabilities. While they have been studied extensively with conventional one-sample-at-a-time synthesis techniques, a more recent high-throughput approach has been developed enabling the synthesis and testing of large libraries of polyanhydrides1. This will facilitate more efficient optimization and design process of these biomaterials for drug and vaccine delivery applications. The method in this work describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries. In this robotically operated method (Figure 1), linear actuators and syringe pumps are controlled by LabVIEW, which enables a hands-free automated protocol, eliminating user error. Furthermore, this method enables the rapid fabrication of micro-scale polymer libraries, reducing the batch size while resulting in the creation of multivariant polymer systems. This combinatorial approach to polymer synthesis facilitates the synthesis of up to 15 different polymers in an equivalent amount of time it would take to synthesize one polymer conventionally. In addition, the combinatorial polymer library can be fabricated into blank or protein-loaded geometries including films or nanoparticles upon dissolution of the polymer library in a solvent and precipitation into a non-solvent (for nanoparticles) or by vacuum drying (for films). Upon loading a fluorochrome-conjugated protein into the polymer libraries, protein release kinetics can be assessed at high-throughput using a fluorescence-based detection method (Figures 2 and 3) as described previously1. This combinatorial platform has been validated with conventional methods2 and the polyanhydride film and nanoparticle libraries have been characterized with 1H NMR and FTIR. The libraries have been screened for protein release kinetics, stability and antigenicity; in vitro cellular toxicity, cytokine production, surface marker expression, adhesion, proliferation and differentiation; and in vivo biodistribution and mucoadhesion1-11. The combinatorial method developed herein enables high-throughput polymer synthesis and fabrication of protein-loaded nanoparticle and film libraries, which can, in turn, be screened in vitro and in vivo for optimization of biomaterial performance.

This method describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries.

组合合成和高通量的蛋白质释放的聚合物薄膜和纳米粒子库

Polyanhydrides are a class of biomaterials with excellent biocompatibility and drug delivery capabilities. While they have been studied extensively with ...

生物工程

Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering, which is a fundamental element to the approach of nanosafety-by-design of nanostructured products for their durable development. This approach is basically a preemptive one in which the focus is put on minimizing the emission of engineered nanomaterials' aerosols during the usage phase of the product's life cycle. This can be attained by altering its material properties during its design phase without compromising with any of its added benefits. In this article, an experimental protocol is presented to investigate the nanosafety-by-design of three commercial nanostructured products with respect to their mechanical solicitation and environmental weathering. The means chosen for applying the mechanical solicitation is an abrasion process and for the environmental weathering, it is an accelerated UV exposure in the presence of humidity and heat. The eventual emission of engineered nanomaterials is studied in terms of their number concentration, size distribution, morphology and chemical composition. The purpose of the protocol is to study the emission for test samples and experimental conditions which are corresponding to real life situations. It was found that the application of the mechanical stresses alone emits the engineered nanomaterials' aerosols in which the engineered nanomaterial is always embedded inside the product matrix, thus, a representative product element. In such a case, the emitted aerosols comprise of both nanoparticles as well as microparticles. But if the mechanical stresses are coupled with the environmental weathering, the experimental protocol reveals then the eventual deterioration of the product, after a certain weathering duration, may lead to the emission of the free engineered nanomaterial aerosols too.

In this article, an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering is presented. Results on the emission of engineered nanomaterials, in the form of aerosols are presented. The specific experimental set-up is described in detail.

实验协议来调查产品的粒子雾化在耐磨和环境下风化

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental ...

Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a technology for regenerative medicine2. Unlike viruses, which have significant safety issues, polymeric nanoparticles can be designed to be non-toxic, non-immunogenic, non-mutagenic, easier to synthesize, chemically versatile, capable of carrying larger nucleic acid cargo and biodegradable and/or environmentally responsive. Cationic polymers self-assemble with negatively charged DNA via electrostatic interaction to form complexes on the order of 100 nm that are commonly termed polymeric nanoparticles. Examples of biomaterials used to form nanoscale polycationic gene delivery nanoparticles include polylysine, polyphosphoesters, poly(amidoamines)s and polyethylenimine (PEI), which is a non-degradable off-the-shelf cationic polymer commonly used for nucleic acid delivery1,3 . Poly(beta-amino ester)s (PBAEs) are a newer class of cationic polymers4 that are hydrolytically degradable5,6 and have been shown to be effective at gene delivery to hard-to-transfect cell types such as human retinal endothelial cells (HRECs)7, mouse mammary epithelial cells8, human brain cancer cells9 and macrovascular (human umbilical vein, HUVECs) endothelial cells10.
A new protocol to characterize polymeric nanoparticles utilizing nanoparticle tracking analysis (NTA) is described. In this approach, both the particle size distribution and the distribution of the number of plasmids per particle are obtained11. In addition, a high-throughput 96-well plate transfection assay for rapid screening of the transfection efficacy of polymeric nanoparticles is presented. In this protocol, poly(beta-amino ester)s (PBAEs) are used as model polymers and human retinal endothelial cells (HRECs) are used as model human cells. This protocol can be easily adapted to evaluate any polymeric nanoparticle and any cell type of interest in a multi-well plate format.

A protocol for nanoparticle tracking analysis (NTA) and high-throughput flow cytometry to evaluate polymeric gene delivery nanoparticles is described. NTA is utilized to characterize the nanoparticle particle size distribution and the plasmid per particle distribution. High-throughput flow cytometry enables quantitative transfection efficacy evaluation for a library of gene delivery biomaterials.

高分子基因传递纳米粒子的纳米粒子跟踪分析和高通量流式细胞仪评价

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a ...

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise composition of these materials is essential, especially in the design of surface catalysts, where the surface concentration of the active component determines the activity of the material. Antimicrobial materials which utilize nanoparticles are a particular focus of this technology. Recently swell encapsulation has emerged as a technique for inserting antimicrobial nanoparticles into a host polymer matrix. Swell encapsulation provides the advantage of localizing the incorporation to the external surfaces of materials, which act as the active sites of these materials. However, quantification of this nanoparticle uptake is challenging. Previous studies explore the link between antimicrobial activity and surface concentration of the active component, but this is not directly visualized. Here we show a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of CdSe/ZnS nanoparticles can be accurately visualized through cross-sectional fluorescence imaging. Using this method, we can quantify the uptake of nanoparticles via swell encapsulation and measure the surface concentration of encapsulated particles, which is key in optimizing the activity of functional materials.

Here we present a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of cadmium selenide quantum dots can be accurately visualized through cross-sectional fluorescence imaging.

纳米粒子 - 聚合物复合材料使用直接荧光成像的先进成分分析

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise ...

A System to Create Stable Nanoparticle Aerosols from Nanopowders

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring minimal amounts of test materials (min. 200 mg), for studying powder aerosolization behavior and aerosol properties. The aerosolization procedure follows the concept of the fluidized-bed process, but occurs in the modified volume of a V-shaped aerosol generator. The airborne particle number concentration is adjustable by controlling the air flow rate. The system supplied stable aerosol generation rates and particle size distributions over long periods (0.5-2 hr and possibly longer), which are important, for example, to study aerosol behavior, but also for toxicological studies. Strict adherence to the operating procedures during the aerosolization experiments ensures the generation of reproducible test results. The critical steps in the standard protocol are the preparation of the material and setup, and the aerosolization operations themselves. The system can be used for experiments requiring stable aerosol concentrations and may also be an alternative method for testing dustiness. The controlled aerosolization made possible with this setup occurs using energy inputs (may be characterized by aerosolization air velocity) that are within the ranges commonly found in occupational environments where nanomaterial powders are handled. This setup and its operating protocol are thus helpful for human exposure and risk assessment.

We designed and developed an effective nanopowder aerosolization setup and operating protocol. The system generated nanoparticle aerosols with stable number concentrations and size distributions for long durations, requiring only small quantities of test material (min. 200 mg).

系统创建从纳米粉体纳米稳定气溶胶

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring ...

A Continuous-flow Photocatalytic Reactor for the Precisely Controlled Deposition of Metallic Nanoparticles

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic nanoparticles is developed. Guidelines for the replication of the reactor and its operation are provided in detail. Three different composite systems (Pt/graphene, Pt/TiO2, and Au/TiO2) with monodisperse and uniformly distributed particles are produced by this reactor, and the photodeposition mechanism, as well as the synthesis optimization strategy, are discussed. The synthesis methods and their technical aspects are described comprehensively. The role of the ultraviolet (UV) dose (in each excitation pulse) on the photodeposition process is investigated and the optimum values for each composite system are provided.

For a continuous and scalable synthesis of noble-metal-based nanocomposites, a novel photocatalytic reactor is developed and its structure, operation principles, and product quality optimization strategies are described.

一种用于金属纳米粒子精确控制沉积的连续流动光催化反应器

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic ...

化学

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is designed and validated for flow field uniformity and cross-contamination among the exposure ports for each concentration. The designed flow field values are compared with the measured values from exposure ports located horizontally and vertically. For this purpose, nanoscale sodium chloride particles are generated as test particles and introduced to the inhalation chamber to evaluate the cross-contamination and concentration maintenance among the chambers, for each concentration group. The results indicate that the designed multiconcentration inhalation chamber can be used in animal inhalation toxicity testing without cross-contamination among concentration groups. Moreover, the designed multiconcentration inhalation toxicity chamber can also be converted to a single-concentration inhalation chamber. Further testing with gas, organic vapor, or non-nanoscale particles will ensure the use of the chamber in the inhalation testing of other test articles.

A nose-only inhalation toxicity chamber capable of testing inhalation toxicity at four different exposure concentrations was designed and validated for flow field uniformity and cross-contamination between the exposure ports for each concentration. Here, we present a protocol to confirm that the designed chamber is effective for inhalation toxicity testing.

提供纳米颗粒四种曝光浓度的单鼻子吸入毒性试验室的研制

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is ...

Whole-Body Nanoparticle Aerosol Inhalation Exposures

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter &lt; 200 nm and a geometric standard deviation &sigma;g &lt; 2.5 5. The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size 6, which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria 5.
A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m3 whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm3) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m3). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is sampling flowrate (m3/min), and t is the sampling time (minute). The chamber pressure, temperature, relative humidity (RH), O2 and CO2 concentrations were monitored and controlled continuously. Nano-TiO2 aerosols collected on Nuclepore filters were analyzed with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis.
In summary, we report that the nano-particle aerosols generated and delivered to our exposure chamber have: 1) steady mass concentration; 2) homogenous composition free of contaminants; 3) stable particle size distributions with a count-median aerodynamic diameter of 157 nm during aerosol generation. This system reliably and repeatedly creates test atmospheres that simulate occupational, environmental or domestic ENM aerosol exposures.

A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation.

全身纳米气溶胶吸入暴露

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle ...

生物学

An Air-liquid Interface Bronchial Epithelial Model for Realistic, Repeated Inhalation Exposure to Airborne Particles for Toxicity Testing

For toxicity testing of airborne particles, air-liquid interface (ALI) exposure systems have been developed for in vitro tests in order to mimic realistic exposure conditions. This puts specific demands on the cell culture models. Many cell types are negatively affected by exposure to air (e.g., drying out) and only remain viable for a few days. This limits the exposure conditions that can be used in these models: usually relatively high concentrations are applied as a cloud (i.e., droplets containing particles, which settle down rapidly) within a short period of time. Such experimental conditions do not reflect realistic long-term exposure to low concentrations of particles. To overcome these limitations the use of a human bronchial epithelial cell line, Calu-3 was investigated. These cells can be cultured at ALI conditions for several weeks while retaining a healthy morphology and a stable monolayer with tight junctions. In addition, this bronchial model is suitable for testing the effects of repeated exposures to low, realistic concentrations of airborne particles using an ALI exposure system. This system uses a continuous airflow in contrast to other ALI exposure systems that use a single nebulization producing a cloud. Therefore, the continuous flow system is suitable for repeated and prolonged exposure to airborne particles while continuously monitoring the particle characteristics, exposure concentration, and delivered dose. Taken together, this bronchial model, in combination with the continuous flow exposure system, is able to mimic realistic, repeated inhalation exposure conditions that can be used for toxicity testing.

Described is the cell culture and exposure method of an in vitro bronchial model for realistic, repeated inhalation exposure to particles for toxicity testing.

用于真实、反复吸入空气颗粒以进行毒性测试的气液接口支气管上皮模型

For toxicity testing of airborne particles, air-liquid interface (ALI) exposure systems have been developed for in vitro tests in order to mimic realistic ...