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The prefix-nano is derived from the Greek word nanos meaning dwarf Nanotechnology involves the manipulation and application of engineered particles or systems that have at least one dimension lessthan 100 nanometers (nm) in length (Hoyt and Mason, 2008). The term nanoparticles applies only to engineered particles (such as metal oxides, carbon nanotubes, fullerenes etc.) and does not apply to particles under 100 nm that occur naturally or are by-products of other processes such as welding fumes, fire smoke, or carbon black

A number of studies have reported that AgNPs[F1] may induce cytotoxicity in phagocytosing cells, such as not only mouse peritoneal macrophages but also human monocytes [38–40]. Further studies suggested that the cytotoxic effects were induced by reactive oxygen species (ROS) resulting in cellular apoptosis, at least low concentrations and short incubation times [37, 41–43]. The production of ROS has also been implicated in DNA damage caused by AgNPs, which was reported in a number of in vitro studies [27, 38, 44]. Caspase-3 is one of the key molecules in apoptosis, and its activation is often considered as the point of no return in apoptosis [45]. Activation of caspase-3 results in the cleavage of (inhibitor of caspase-activated DNAse) ICAD and translocation of (caspase activated DNAse) CAD to the nucleus, ultimately resulting in DNA fragmentation. The most prominent event in the early stages of apoptosis is internucleosomal DNA cleavage by endonuclease activities [46]. Previous studies suggested that AgNPs treated cancer cell, and noncancer cells revealed enhanced caspase-3 activity and formation of significant DNA laddering [14, 15, 47].

Evolution of a bimetallic nanocatalyst

TEM image of platinum/cobalt bimetallic nanoparticle catalyst in action shows that during the oxidation reaction, cobalt atoms migrate to the surface of the particle, forming a cobalt oxide epitaxial film, like water on oil.---Atomic-scale snapshots of a bimetallic nanoparticle catalyst in action have provided insights that could help improve the industrial process by which fuels and chemicals are synthesized from natural gas, coal or plant biomass. A multi-national lab collaboration led by researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) has taken the most detailed look ever at the evolution of platinum/cobalt bimetallic nanoparticles during reactions in oxygen and hydrogen gases.--"Using in situ aberration-corrected transmission electron microscopy (TEM), we found that during the oxidation reaction, cobalt atoms migrate to the nanoparticle surface, forming a cobalt oxide epitaxial film, like water on oil," says Haimei Zheng, a staff scientist in Berkeley Lab's Materials Sciences Division who led this study. "During the hydrogen reduction reaction, cobalt atoms migrate back into the bulk, leaving a monolayer of platinum on the surface. This atomic information provides an important reference point for designing and engineering better bimetallic catalysts in the future."--Bimetallic catalysts are drawing considerable attention from the chemical industry these days because in many cases they offer superior performances to their monometallic counterparts. There is also the possibility of tuning their catalytic performances to meet specific needs. A bimetallic catalyst of particular interest entails the pairing of platinum, the gold standard of monometallic catalysts, with cobalt, a lesser catalyst but one that is dramatically cheaper than platinum. The platinum/cobalt catalyst is not only considered a model system for the study of other bimetallic nanocatalysts, it is also an excellent promoter of the widely used Fischer-Tropsch process, in which mixtures of hydrogen and carbon monoxide are converted into long-chain carbons for use as fuels or in low-temperature fuel cells.

"While there have been many studies on platinum/cobalt and other bimetallic catalysts, information on how reactions proceed atomically and what the morphology looks like has been missing," Zheng says. "To acquire this information it was necessary to map the atomic structures in reactive environments in situ, which we did using specially equipped TEMs."--The in situ environmental TEM experiments were carried out at both the Environmental Molecular Sciences Laboratory, which is located at PNNL, and at BNL's Center for Functional Nanomaterials. Ex situ aberration-corrected TEM imaging was done at Berkeley Lab's National Center for Electron Microscopy using TEAM 0.5, the world's most powerful TEM.--"This work is an excellent example of collaborative team-work among multiple institutes," Zheng says. "Having access to such high-end resources and being able to form such close team collaborations strengthens our ability to tackle challenging scientific problems."--The in situ aberration corrected TEM studies of Zheng and her colleagues revealed that because of a size mismatch between the lattices of the cobalt oxide epitaxial film and the platinum surface, the cobalt oxide lattice is compressively strained at the interface to fit on the platinum lattice[F2]. As the strain energy relaxes, the cobalt oxide film starts breaking up to form distinct molecular islands on the platinum surface. This reduces the effective reaction surface area per volume and creates catalytic voids, both of which impact overall catalytic performance.--"By taking this segregation of the platinum and cobalt atoms into consideration, the interfacial strain that arises during oxidation can be predicted," Zheng says. "We can then design nanoparticle catalysts to ensure that during reactions the material with higher catalytic performance will be on surface of the nanoparticles."--Zheng adds that the ability to observe atomic scale details of the evolution of the structure of nanoparticles in their reactive environments not only opens the way to a deeper understanding of bimetallic nanoparticle catalysis, it also allows for the study of a wider variety of nanoparticle systems where reaction pathways remain elusive.--This research was supported by the DOE Office of Science. It made use of the resources at the Environmental Molecular Sciences Laboratory, the Center for Functional Nanomaterials, and the National Center for Electron Microscope, user facilities supported by DOE's Office of Science.--Story Source--The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.--Journal Reference-Huolin L. Xin, Selim Alayoglu, Runzhe Tao, Arda Genc, Chong-Min Wang, Libor Kovarik, Eric A. Stach, Lin-Wang Wang, Miquel Salmeron, Gabor A. Somorjai, Haimei Zheng. Revealing the Atomic Restructuring of Pt–Co Nanoparticles. Nano Letters, 2014; 140519100039000 DOI: 10.1021/nl500553a

Study improves understanding of method for creating multi-metal nanoparticles

This Shows how researchers created the core/shell nanoparticles, and alloy nanoparticles, from gold and silver.--A new study from researchers at North Carolina State University sheds light on how a technique that is commonly used for making single-metal nanoparticles can be extended to create nanoparticles consisting of two metals -- and that have tunable properties. The study also provides insight into the optical properties of some of these nanoparticles.-Tuning the optical properties of nanoparticles is of interest for applications such as security technology, and for use in making chemical reactions more efficient [F3]-- which has multiple industrial and environmental applications.-The researchers created core/shell nanoparticles with a gold core and silver shell, as well as alloy nanoparticles, which mix the gold and silver. The researchers also characterized the optical properties of these nanoparticles. "Silver and gold have unique optical properties arising from their specific interactions with the electric field of light," says Dr. Joe Tracy, an assistant professor of materials science and engineering at NC State and co-author of a paper describing the study. "By manipulating the ratio of the metals, and whether the nanoparticles have core/shell or alloy structures, we can alter their optical properties with control."-The researchers synthesized the nanoparticles using a technique called "digestive ripening." The technique has been used to create single-metal particles for approximately a decade, but there have been limited studies of core/shell and alloy nanoparticles created using digestive ripening. However, the comprehensive nature of this study may make it more common.-"This study, along with related work by others, shows that digestive ripening is a viable method for creating multi-component metal nanoparticles. We used gold and silver, but the same principles would likely apply to other metals," Tracy says. "Our detailed evaluation of this synthetic approach should help other researchers explore other kinds of binary metal nanoparticles."-Digestive ripening relies on the use of ligands, which are small organic molecules with parts that bond directly to metals. The ligands are usually anchored to the metal cores of the nanoparticles and prevent the nanoparticles from clumping together, which allows them to be suspended in solution[F4]. Digestive ripening occurs when the ligands are able to transport metal atoms from the core of one nanoparticle to another -- resulting in a more homogenous size distribution among the nanoparticles.-The researchers used digestive ripening to create a solution of gold nanoparticles of similar size. When they introduced silver acetate into the solution, the ligands transported silver atoms to the surfaces of the gold nanoparticles, resulting in nanoparticles with gold cores and silver shells.-Researchers then transferred the nanoparticles into a second solution, containing a different ligand. Heating this second solution to 250 degrees Celsius caused the metals to diffuse into each other -- creating nanoparticles made of a gold-silver alloy.-The researchers also created gold-silver alloy nanoparticles by skipping the shell-creation step, introducing silver acetate into the second solution, and raising the temperature to 250 degrees Celsius. This "shortcut" method has the benefit of simplifying control over the gold-to-silver ratio of the alloy.-The paper, "Synthesis of Au(core)/Ag(shell) Nanoparticles and their Conversion to AuAg Alloy Nanoparticles," was published online Dec. 13 by the journal Small. The research was funded by the National Science Foundation and NC State. The lead author of the paper is Matthew Shore, who was an undergraduate at NC State when the research was done. Co-authors include Tracy, NC State Ph.D. student Aaron Johnston-Peck, former NC State postdoc Dr. Junwei Wang, and University of North Carolina at Chapel Hill assistant professor Dr. Amy Oldenburg.-NC State's Department of Materials Science and Engineering is part of the university's College of Engineering.-Story Source-The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.-Journal Reference-Matthew S. Shore, Junwei Wang, Aaron C. Johnston-Peck, Amy L. Oldenburg, Joseph B. Tracy. Synthesis of Au(Core)/Ag(Shell) Nanoparticles and their Conversion to AuAg Alloy Nanoparticles. Small, 2010; DOI: 10.1002/smll.201001138

Lungs may suffer when certain elements go nano

Missouri University of Science and Technology-Nanoparticles are used in all kinds of applications -- electronics, medicine, cosmetics, even environmental clean-ups. More than 2,800 commercially available applications are now based on nanoparticles, and by 2017, the field is expected to bring in nearly $50 billion worldwide.

But this influx of nanotechnology is not without risks, say researchers at Missouri University of Science and Technology.-"There is an urgent need to investigate the potential impact of nanoparticles on health and the environment," says Yue-Wern Huang, professor of biological sciences at Missouri S&T.-Huang and his colleagues have been systematically studying the effects of transition metal oxide nanoparticles on human lung cells. These nanoparticles are used extensively in optical and recording devices, water purification systems, cosmetics and skin care products, and targeted drug delivery, among other applications.-"In their typical coarse powder form, the toxicity of these substances is not dramatic[F5]," says Huang. "But as nanoparticles with diameters of only 16-80 nanometers, the situation changes significantly."-The researchers exposed both healthy and cancerous human lung cells to nanoparticles composed of titanium, chromium, manganese, iron, nickel, copper and zinc compounds -- transition metal oxides that are on the fourth row of the periodic table. The researchers discovered that the nanoparticles' toxicity to the cells, or cytotoxicity, increased as they moved right on the periodic table.-"About 80 percent of the cells died in the presence of nanoparticles of copper oxide and zinc oxide,"[F6] says Huang. "These nanoparticles penetrated the cells and destroyed their membranes. The toxic effects are related to the nanoparticles' surface electrical charge and available docking sites."-Huang says that certain nanoparticles released metal ions -- called ion dissolution -- which also played a significant role in cell death.-Huang is now working on new research that may help reduce nanoparticles' toxicity and shed light on how nanoparticles interact with cells.--"We are coating toxic zinc oxide nanoparticles with non-toxic nanoparticles to see if zinc oxide's toxicity can be reduced," Huang says. "We hope this can mitigate toxicity without compromising zinc oxide's intended applications. We're also investigating whether nanoparticles inhibit cell division and influence cell cycle."--The researchers' findings, "Cytotoxicity in the age of nano: The role of fourth period transition metal oxide nanoparticle physicochemical properties," were published in the Nov. 25, 2013, issue of the journal Chemico-Biological Interactions.--Story Source-The above story is based on materials provided by Missouri University of Science and Technology. Note: Materials may be edited for content and length.--Journal Reference-Yue-Wern Huang et al. Cytotoxicity in the age of nano: The role of fourth period transition metal oxide nanoparticle physicochemical properties. Chemico-Biological Interactions, January 2014

Are silver nanoparticles harmful?

Silver nanoparticles cause more damage to testicular cells than titanium dioxide nanoparticles, according to a recent study by the Norwegian Institute of Public Health. However, the use of both types may affect testicular cells with possible consequences for fertility.--Commonly used---Nanotechnology is increasingly used in consumer products, medicines and building products. The potential risks of using engineered nanoparticles need to be monitored so that the industry can develop products that are safe for humans and nature.--Previous research has shown that nanoparticles can cross both the blood-brain barrier and blood-testes barrier in mice and rats, and are taken up by cells. This study aimed to see if silver and titanium dioxide nanoparticles had any effect on human and mice testicular cells.--The researchers found that silver nanoparticles had a toxic effect on cells, suppressing cellular growth and multiplication and causing cell death depending on concentrations and duration of exposure. The effect was weaker for titanium dioxide nanoparticles, although both types did cause cell type-specific DNA damage, with possible implications on reproduction as well as human and environmental health.--"It seems that the type of nanoparticle, and not the size alone, may be the limiting factor" says Nana Asare, primary author of the study published in Toxicology.--Further studies using in vivo models are needed to study the impact of nanoparticles on reproductive health.--The researchers used cells from a human testicular carcinoma[F7] cell line and testicular cells from two strains of mice, one of which is genetically modified to serve as a representative model for human male reproductive toxicity. The cells were exposed to titanium dioxide nanoparticles (21nm) and two different sizes of silver nanoparticles (20 nm and 200nm) over different concentrations and time periods. Both sizes of silver nanoparticles inhibited normal cell function and caused more cell death than the titanium dioxide nanoparticles. In particular, the 200 nm silver particles caused a concentration-dependent increase in DNA damage in the human cells.

Story Source-The above story is based on materials provided by Norwegian Institute of Public Health. Note: Materials may be edited for content and length.--Journal Reference-Nana Asare, Christine Instanes, Wiggo J. Sandberg, Magne Refsnes, Per Schwarze, Marcin Kruszewski, Gunnar Brunborg. Cytotoxic and genotoxic effects of silver nanoparticles in testicular cells. Toxicology, 2012; 291 (1-3): 65 DOI: 10.1016/j.tox.2011.10.022

Toxic nanoparticles might be entering human food supply

Graduate student Zhong Zhang applies silver nanoparticles to a piece of fruit. In a recent study, University of Missouri researchers found that these particles could pose a potential health risk to humans and the environment.-Over the last few years, the use of nanomaterials for water treatment, food packaging, pesticides, cosmetics and other industries has increased. For example, farmers have used silver nanoparticles as a pesticide because of their capability to suppress the growth of harmful organisms[F8]. However, a growing concern is that these particles could pose a potential health risk to humans and the environment. In a new study, researchers at the University of Missouri have developed a reliable method for detecting silver nanoparticles in fresh produce and other food products.-"More than 1,000 products on the market are nanotechnology-based products," said Mengshi Lin, associate professor of food science in the MU College of Agriculture, Food and Natural Resources. "This is a concern because we do not know the toxicity of the nanoparticles. Our goal is to detect, identify and quantify these nanoparticles in food and food products and study their toxicity as soon as possible."-Lin and his colleagues, including MU scientists Azlin Mustapha and Bongkosh Vardhanabhuti, studied the residue and penetration of silver nanoparticles on pear skin. First, the scientists immersed the pears in a silver nanoparticle solution similar to pesticide application. The pears were then washed and rinsed repeatedly. Results showed that four days after the treatment and rinsing, silver nanoparticles were still attached to the skin, and the smaller particles were able to penetrate the skin and reach the pear pulp.-"The penetration of silver nanoparticles is dangerous to consumers because they have the ability to relocate in the human body after digestion," Lin said. "Therefore, smaller nanoparticles may be more harmful to consumers than larger counterparts."-When ingested, nanoparticles pass into the blood and lymph system, circulate through the body and reach potentially sensitive sites such as the spleen, brain, liver and heart.-The growing trend to use other types of nanoparticles has revolutionized the food industry by enhancing flavors, improving supplement delivery, keeping food fresh longer and brightening the colors of food. However, researchers worry that the use of silver nanoparticles could harm the human body.-"This study provides a promising approach for detecting the contamination of silver nanoparticles in food crops or other agricultural products," Lin said.-Members of Lin's research team also included Zhong Zang, a food science graduate student. The study was published in the Journal of Agricultural and Food Chemistry.-Story Source-The above story is based on materials provided by University of Missouri-Columbia. The original article was written by Diamond Dixon. Note: Materials may be edited for content and length.-Journal Reference-Zhong Zhang, Mengshi Lin, Sha Zhang, Bongkosh Vardhanabhuti. Detection of Aflatoxin M1 in Milk by Dynamic Light Scattering Coupled with Superparamagnetic Beads and Gold Nanoprobes. Journal of Agricultural and Food Chemistry, 2013; 61 (19): 4520 DOI: 10.1021/jf400043z

New Insights Into Health And Environmental Effects Of Carbon Nanoparticles

Researchers are reporting that carbon nanoparticles can be transmitted by fruit flies and that certain nanoparticles can be toxic to adult flies.

A new study raises the possibility that flies and other insects that encounter nanomaterial "hot spots," or spills, near manufacturing facilities in the future could pick up and transport nanoparticles on their bodies, transferring the particles to other flies or habitats in the environment. ---The study on carbon nanoparticles — barely 1/5,000th the width of a human hair —is scheduled for the Aug. 15 issue of ACS' Environmental Science & Technology. -David Rand and Robert Hurt and colleagues note that emergence of a nanotechnology industry is raising concerns about the potential adverse health and environmental effects of nanoparticles. These materials show promise for use in a wide range of products, including cosmetics, pharmaceuticals, and electronics.--The study focused on determining how different kinds of exposure to nanoparticles affected larval and adult fruit flies. Scientists use fruit flies as stand-ins for humans and other animals in certain kinds of research. There were no apparent ill effects on fruit fly larvae that ate food containing high concentrations of nanoparticles. However, adult flies died or were incapacitated when their bodies were exposed to large amounts of certain nanoparticles.--During the experiments, the researchers noted that contaminated flies transferred nanoparticles to other flies, and realized that such transfer could also occur between flies and humans in the future. The transfer involved very low levels of nanoparticles, which did not have adverse effects on the fruit flies. Since larvae can tolerate very high doses of nanoparticles in the diet, but adult flies show very different sensitivities, the environmental impact depends on the ecological context of nanoparticle release.--Story Source-The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.--Journal Reference-Xinyuan Liu, Daniel Vinson, Dawn Abt, Robert H. Hurt, David M. Rand. Differential Toxicity of Carbon Nanomaterials in Drosophila: Larval Dietary Uptake is Benign, but Adult Exposure Causes Locomotor Impairment and Mortality. Environmental Science & Technology, DOI: 10.1021/es901079z

Scientists use laser imaging to assess safety of zinc oxide nanoparticles in sunscreen

Overlay of the confocal/multiphoton image of the excised human skin. Yellow color represents skin autofluorescence excited by 405 nm; Purple color represents zinc oxide nanoparticle distribution in skin (stratum corneum) excited by 770 nm, with collagen-induced faint SHG signals in the dermal layer.

Ultra-tiny zinc oxide (ZnO) particles with dimensions less than one-ten-millionth of a meter are among the ingredients list of some commercially available sunscreen products, raising concerns about whether the particles may be absorbed beneath the outer layer of skin. To help answer these safety questions, an international team of scientists from Australia and Switzerland have developed a way to optically test the concentration of ZnO nanoparticles at different skin depths. They found that the nanoparticles did not penetrate beneath the outermost layer of cells when applied to patches of excised skin. --The results, which were published this month in the Optical Society's (OSA) open-access journal Biomedical Optics Express, lay the groundwork for future studies in live patients.-The high optical absorption of ZnO nanoparticles in the UVA and UVB range, along with their transparency in the visible spectrum when mixed into lotions, makes them appealing candidates for inclusion in sunscreen cosmetics. However, the particles have been shown to be toxic to certain types of cells within the body, making it important to study the nanoparticles' fate after being applied to the skin. By characterizing the optical properties of ZnO nanoparticles, the Australian and Swiss research team found a way to quantitatively assess how far the nanoparticles might migrate into skin.--The team used a technique called nonlinear optical microscopy, which illuminates the sample with short pulses of laser light and measures a return signal. Initial results show that ZnO nanoparticles from a formulation that had been rubbed into skin patches for 5 minutes, incubated at body temperature for 8 hours, and then washed off, did not penetrate beneath the stratum corneum, or topmost layer of the skin. The new optical characterization should be a useful tool for future non-invasive in vivo studies, the researchers write.--Story Source-The above story is based on materials provided by Optical Society of America. Note: Materials may be edited for content and length.-Journal Reference-Zhen Song, Timothy A. Kelf, Washington H. Sanchez, Michael S. Roberts, Jaro Rička, Martin Frenz, Andrei V. Zvyagin. Characterization of optical properties of ZnO nanoparticles for quantitative imaging of transdermal transport. Biomedical Optics Express, 2011; 2 (12): 3321 DOI: 10.1364/BOE.2.003321

Evidence that nanoparticles in sunscreens could be toxic if accidentally eaten

Sunscreens contain nanoparticles of zinc oxide -- used to prevent the damaging effects of sunlight -- that can harm colon cells and may be toxic if accidentally eaten.--Scientists are reporting that particle size affects the toxicity of zinc oxide, a material widely used in sunscreens. Particles smaller than 100 nanometers are slightly more toxic to colon cells than conventional zinc oxide. Solid zinc oxide was more toxic than equivalent amounts of soluble zinc, and direct particle to cell contact was required to cause cell death. Their study is in ACS' Chemical Research in Toxicology, a monthly journal.-Philip Moos and colleagues note that there is ongoing concern about the potential toxicity of nanoparticles of various materials, which may have different physical and chemical properties than larger particles. Barely 1/50,000 the width of a human hair, nanoparticles are used in foods, cosmetics and other consumer products. Some sunscreens contain nanoparticles of zinc oxide. "Unintended exposure to nano-sized zinc oxide from children accidentally eating sunscreen products is a typical public concern, motivating the study of the effects of nanomaterials in the colon," the scientists note.-Their experiments with cell cultures of colon cells compared the effects of zinc oxide nanoparticles to zinc oxide sold as a conventional powder. They found that the nanoparticles were twice as toxic to the cells as the larger particles.-Although the nominal particle size was 1,000 times larger, the conventional zinc oxide contained a wide range of particle sizes and included material small enough to be considered as nanoparticles. The concentration of nanoparticles that was toxic to the colon cells was equivalent to eating 2 grams of sunscreen -- about 0.1 ounce. This study used isolated cells to study biochemical effects and did not consider the changes to particles during passage through the digestive tract. The scientists say that further research should be done to determine whether zinc nanoparticle toxicity occurs in laboratory animals and people.--Story Source-The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.-Journal Reference-Moos et al. ZnO Particulate Matter Requires Cell Contact for Toxicity in Human Colon Cancer Cells. Chemical Research in Toxicology, 2010; 100215135857018 DOI: 10.1021/tx900203v

X-rays reveal uptake of nanoparticles by soybean crops

Metals contained in nanoparticles can enter into the food chain. Scientists have, for the first time, traced the nanoparticles taken up from the soil by crop plants and analysed the chemical states of their metallic elements. Zinc was shown to dissolve and accumulate throughout the plants, whereas the element cerium did not dissolve into plant tissue. The results contribute to the controversial debate on plant toxicity of nanoparticles and whether engineered nanoparticles can enter into the food chain.---The study was published on 6 February 2013 in the journal ACS Nano.--The international research team was led by Jorge Gardea-Torresdey from the University of Texas in El Paso and also comprised scientists from the University of California in Santa Barbara, the SLAC National Accelerator Laboratory in Stanford (California), and the European Synchrotron Radiation Facility in Grenoble (France).---Nanoparticles are present everywhere, for example in the fine dust of wood fires. Even a simple chemical compound behaves differently as a nanoparticle, mostly due to the increased specific surface area and reactivity. These appealing properties are why so-called Engineered Nanoparticles (ENPs) are now widely used in industrial processing and consumer goods. At the same time, their high reactivity has raised concerns about their fate, transport and toxicity in the environment. "A growing number of products containing ENPs are in the market and eventually they will get into the soil, water and air. This is why it is very important to study the interactions of crops with nanoparticles, as their possible translocation into the food chain starts here." says Jorge Gardea-Torresdey, a Professor and Chair of the Department of Chemistry at the University of Texas at El Paso.---The scientists focused on soya bean plants (glycine max), the fifth largest crop in global agricultural production, and the second in the U.S. The soil in which the plants were grown was mixed with zinc oxide (ZnO) and cerium dioxide (CeO₂, nanoceria) nanoparticles, which are among the most highly used in industry. ZnO is widely used in sunscreen products, as gas sensors, antibacterial agents, optical and electrical devices, and as pigments. Nanoceria is an excellent catalyst for internal combustion and oil cracking processes and is also used in gas sensors, sunscreen products and cosmetic creams.---After the soya bean plants had been grown to maturity in greenhouses, the distribution of zinc and cerium throughout the plants was studied. The use of microscopic synchrotron X-ray beams at the Stanford Synchrotron Radiation Lightsource (SSRL) and at the ESRF, enabled scientists to determine the chemical form of these metals, i.e. whether they were still bound to nanoparticles or had dissolved and bound with plant tissue. "We used X-ray beams 1000 times thinner than a human hair, and the way in which they are absorbed tells us whether, at the microscopic spot they hit, zinc and cerium were present, and whether they formed part of a nanoparticle in the plant or not." says Hiram Castillo, a scientist at the ESRF in Grenoble.--Cerium was shown to be present not only in the nodules close to the soil but had also reached the plant pods. A detailed spectral analysis of the X-ray signals showed that the cerium in the nodules and pods was in the same chemical state as in the nanoparticles. However, part of the cerium had changed its oxidation state from Ce(IV) to Ce(III) which can alter the chemical reactivity of the nanoparticles.---Zinc was detected in nodules, stems and pods in concentrations higher than in a control group of plants. The spectral analysis did not show the presence of zinc in the plants bound as ZnO nanoparticles which means that the zinc in the nanoparticles had been biotransformed. The spectra suggest that organic acids present in the plants such as citrate, are the probable ligands for the zinc.---"As zinc is present in most plants, it didn't come as a surprise that zinc from the nanoparticles in the soil can enter into the plant tissue. But plants can also assimilate more dangerous elements like cadmium or arsenic which, when used in nanoparticles, might pose a real threat." says Hiram Castillo. "Our results have also shown that CeO₂ nanoparticles can be taken up by food crops when present in the soil. Cerium has no chemical partner in the plant tissue and is not biotransformed in the soya bean but still reaches the food chain and the next soya bean plant generation." adds Jorge Gardea-Torresdey.--"One must keep in mind that once engineered nanoparticles enter the food chain, this is an accumulative process. CTolerable levels today can become dangerous tomorrow.B This is why it is important to study not only whether man-made nanoparticles can be taken up from soil but also how they are biotransformed in the plants.[F9]" concludes Jorge Gardea-Torresdey.--Arturo A. Keller of the University of California in Santa Barbara and Co-Director of the UC Center for the Environmental Implications of Nanotechnology, who was not involved in this research, comments:

"It's a fascinating paper with some genuine concerns in terms of potential health implications. Whilst we are not able to directly attribute nanoparticle ingestion to any particular disease or symptoms, we know from the latest laboratory studies the potency some have in terms of infiltrating our cells and tissue and causing harm. The fact that these potentially dangerous particles are being taken up by such a common crop suggests a need to review what materials are used in agriculture around the world. In particular, it raises concern over the use of treated waste water to irrigate crops all over the world which may provide a route for these potentially dangerous particles to get into our bodies if the content of the water is not more tightly managed."[F10]---Story Source-The above story is based on materials provided by European Synchrotron Radiation Facility. Note: Materials may be edited for content and length.--Journal Reference-Jose A. Hernandez-Viezcas, Hiram Castillo-Michel, Joy Cooke Andrews, Marine Cotte, Cyren Rico, Jose R. Peralta-Videa, Yuan Ge, John H. Priester, Patricia Ann Holden, Jorge L. Gardea-Torresdey. In SituSynchrotron X-ray Fluorescence Mapping and Speciation of CeO2and ZnO Nanoparticles in Soil Cultivated Soybean (Glycine max). ACS Nano, 2013; 130122094014001 DOI: 10.1021/nn305196q

Nanoparticle thin films that self-assemble in one minute

Upon solvent annealing, supramolecules made from gold nanoparticles and block copolymers will self-assemble into highly ordered thin films in one minute.--The days of self-assembling nanoparticles taking hours to form a film over a microscopic-sized wafer are over. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have devised a technique whereby self-assembling nanoparticle arrays can form a highly ordered thin film over macroscopic distances in one minute.--Ting Xu, a polymer scientist with Berkeley Lab's Materials Sciences Division, led a study in which supramolecules based on block copolymers were combined with gold nanoparticles to create nanocomposites that under solvent annealing quickly self-assembled into hierarchically-structured thin films spanning an area of several square centimeters. The technique is compatible with current nanomanufacturing processes and has the potential to generate new families of optical coatings for applications in a wide number of areas including solar energy, nanoelectronics and computer memory storage. This technique could even open new avenues to the fabrication of metamaterials, artificial nanoconstructs that possess remarkable optical properties.--"Our technique can rapidly generate amazing nanoparticle assemblies over areas as large as a silicon wafer," says Xu, who also holds a joint appointment with the University of California (UC) Berkeley's Departments of Materials Sciences and Engineering, and Chemistry. "You can think of it as pancake batter that you can spread over a griddle, wait one minute and you have a pancake ready to eat."-Xu is the corresponding author of a paper describing this research in Nature Communications titled "Rapid fabrication of hierarchically structured supramolecular nanocomposite thin films in one minute." Co-authors are Joseph Kao, Kari Thorkelsson, Peter Bai, Zhen Zhang and Cheng Sun.--Nanoparticles function as artificial atoms with unique optical, electrical and mechanical properties. If nanoparticles can be induced to self-assemble into complex structures and hierarchical patterns, similar to what nature does with proteins, it would enable mass-production of devices a thousand times smaller those used in today's microtechnology.--Xu and her research group have been steadily advancing towards this ultimate goal. Most recently their focus has been on the use of block copolymer-based supramolecular solutions to direct the self-assembly of nanoparticle arrays. A supramolecule is a group of molecules that act as a single molecule able to perform a specific set of functions. Block copolymers are long sequences or "blocks" of one type of monomer bound to blocks of another type of monomer that have an innate ability to self-assemble into well-defined arrays of nano-sized structures over macroscopic distances.--"Block copolymer-based supramolecules self-assemble and form a wide range of morphologies that feature microdomains typically a few to tens of nanometers in size," Xu says. "As their size is comparable to that of nanoparticles, the microdomains of supramolecules provide an ideal structural framework for the self-assembly of nanoparticle arrays."--In the supramolecular technique devised by Xu and her colleagues, arrays of gold nanoparticles were incorporated into solutions of supramolecules to form films that were about 200 nanometers thick. Through solvent annealing, using chloroform as the solvent, the nanoparticle arrays organized into three-dimensional cylindrical microdomains that were packed into distorted hexagonal lattices in parallel orientation with the surface. This display of hierarchical structural control in nanoparticle self-assembly was impressive but was only half the game.--"To be compatible with nanomanufacturing processes, the self-assembly fabrication process must also be completed within a few minutes to minimize any degradation of nanoparticle properties caused by exposure to the processing environment," Xu says.--She and her group systematically analyzed the thermodynamics and kinetics of self-assembly in their supramolecular nanocomposite thin films upon exposure to solvent vapor. They found that by optimizing a single parameter, the amount of solvent, assembly kinetics could be precisely tailored to produce hierarchically structured thin films in a single minute.--"By constructing our block copolymer-based supramolecules from small molecules non-covalently attached to polymer side chains, we changed the energy landscape so that solvent content became the most important factor," Xu says. "This enabled us to achieve fast-ordering of the nanoparticle arrays with the addition of only a very small amount of solvent, about 30-percent of the fraction of a 200 nanometer thick film."--- The optical properties of nanocomposite thin films depend on the properties of individual nanoparticles and on well-defined inter-particle distances along different directions. Given that the dimensions of the gold nanoparticle arrays are at least one order of magnitude smaller than the wavelengths of visible light, the supramolecular technique of Xu and her colleagues has strong potential to be used for making metamaterials. These artificial materials have garnered a lot of attention in recent years because their electromagnetic properties are unattainable in natural materials. For example, a metamaterial can have a negative index of refraction, the ability to bend light backwards, unlike all materials found in nature, which bend light forward.-"Our gold nanocomposite thin films exhibit strong wavelength- dependent optical anisotropy that can be tailored simply by varying the solvent treatment," Xu says. "This presents a viable alternative to lithography for making metamaterials."--While Xu and her colleagues used gold nanoparticles in their films, the supramolecular approach is compatible with nanoparticles of other chemical compositions as well.--"We should be able to create a library of nanoparticle assemblies engineered for light manipulation and other properties," Xu says, "using a technique that is compatible with today's most widely used nanomanufacturing processes, including blade coating, ink-jet printing and dynamic zone annealing."--Story Source-The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. The original article was written by Lynn Yarris. Note: Materials may be edited for content and length.-Journal Reference-Joseph Kao, Kari Thorkelsson, Peter Bai, Zhen Zhang, Cheng Sun, Ting Xu. Rapid fabrication of hierarchically structured supramolecular nanocomposite thin films in one minute. Nature Communications, 2014; 5 DOI: 10.1038/ncomms5053

Nano-sized particles -- bits of matter a few billionths of a meter in size, or more than a hundred times smaller than the stuff of today's microtechnologies -- display highly coveted properties not found in macroscopic materials, including optical, electronic, magnetic, etc. The promise of nanotechnololgy is that exploiting these unique properties on a commercial scale could yield such "game-changers" as sustainable, clean and cheap energy, and the creation on demand of new materials with properties tailored to meet specific needs. Realizing this promise starts with nanoparticles being able to organize themselves into complex structures and hierarchical patterns, similar to what nature routinely accomplishes with proteins.--"Precise control of the spatial organization of nanoparticles and other nanoscopic building blocks over multiple length scales has been a bottleneck in the bottom-up generation of technologically important materials," says Xu. "Most of the approaches that have been used so far have involved surface modifications."--Small as they are, nanoparticles are essentially all surface so any process that modifies the surface of a nanoparticle can profoundly change the properties of that particle. Precisely arranging these nanoparticles is critical to tailoring the macroscopic properties during nanoparticle assembly. Although DNA has been used to induce self-assembly of nanoparticles with a high degree of precision, this approach only works well for organized arrays that are limited in size; it is impractical for large-scale fabrication. Xu believes a better approach is to use block copolymers -- long sequences or "blocks" of one type of monomer molecule bound to blocks of another type of monomer molecule.--"Block copolymers readily self-assemble into well-defined arrays of nanostructures over macroscopic distances," she says. "They would be an ideal platform for directing the assembly of nanoparticles except that block copolymers and nanoparticles are not particularly compatible with one another from a chemistry standpoint. A mediator is required to bring them together."--Xu and her group found such a "mediator" in the form of small molecules that will join with nanoparticles and then able attach themselves and their nanoparticle partners to the surface of a block copolymer. For this study, Xu and her group used two different types of small molecules, surfactants (wetting agents) dubbed "PDP" and "OPAP." These small molecules can be stimulated by light (PDP) or heat (OPAP) to sever their connection to the surface of a block copolymer and be repositioned to another location along the polymeric chain[F11]. In this manner, the spatial distribution of the small molecule mediators and their nanoparticle partners can be precisely directed with no need to modify either the nanoparticles or the polymers.--"The beauty of this technique is that it involves no sophisticated chemistry," says Xu. "It really is a plug and play technique, in which you simply mix the nanoparticles with the block copolymers and then add whatever small molecules you need."For this study, Xu and her colleagues added PDP or OPAP small molecules to various blends of nanoparticles, such as cadmium selenide and lead sulfide, mixed in with a commercial block copolymer -- polystyrene-block-poly (4-vinyl pyridine). While she and her group worked with light and heat, she says other stimuli, such as pH, could also be used to reposition small molecules and their nanoparticle partners along block copolymer formations. Strategic substitutions of different types of stimulus-responsive small molecules could serve as a mechanism for structural fine-tuning or for incorporating specific functional properties into nanocomposites. Xu and her colleagues are now in the process of adding functionality to their self-assembly technique.--"Bring together the right basic components -- nanoparticles, polymers and small molecules -- stimulate the mix with a combination of heat, light or some other factors, and these components will assemble into sophisticated structures or patterns," says Xu. "It is not dissimilar from how nature does it."--This research was supported in part by the U.S. Department of Energy's Office of Science and in part by the Army Research Office and National Science Foundation. The nanoparticles were synthesized at Berkley Lab's Molecular Foundry and characterizations of the nanoparticle assemblies were performed at Beamline 7.3.3 of Berkeley Lab's Advanced Light Source. Both the Molecular Foundry and the Advanced Light Source are DOE Office of Science national user facilities.--Story Source-The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.--Journal Reference-Ting Xu, Yue Zhao, Kari Thorkelsson, Alexander Mastroianni, Thomas Schilling, Joseph Luther, Benjamin Rancatore, Kazuyuki Matsunaga, Hiroshi Jinnai, Yue Wu, Daniel Poulsen, Jean Fréchet and Paul Alivisatos. Small molecule-directed nanoparticle assembly towards stimuli-responsive nanocomposites. Nature Materials, (in press)

Synthetic and biological nanoparticles combined to produce new metamaterials

Scientists have succeeded in organizing virus particles, protein cages and nanoparticles into crystalline materials. These nanomaterials are important for applications in sensing, optics, electronics and drug delivery.

Two different protein cages, cowpea chlorotic mottle virus (blue) and Pyrococcus furiosus ferritin (red), can be used to guide the assembly of binary nanoparticles superlattices through tunable electrostatic interactions with charged gold nanoparticles (yellow).---

Scientists from Aalto University, Finland, have succeeded in organising virus particles, protein cages and nanoparticles into crystalline materials. These nanomaterials studied by the Finnish research group are important for applications in sensing, optics, electronics and drug delivery.-Layer structures, or superlattices, of crystalline nanoparticles have been extensively studied in recent years. The research develops hierarchically structured nanomaterials with tuneable optical, magnetic, electronic and catalytic properties. Such biohybrid superlattices of nanoparticles and proteins would allow the best features of both particle types to be combined. They would comprise the versatility of synthetic nanoparticles and the highly controlled assembly properties of biomolecules, according to the authors.-The research group also discovered magnetic self-assemblies of ferritin protein cages and gold nanoparticles. These magnetic assemblies can modulate efficiently spin-spin relaxation times of surrounding protons in water by enhancing the spin dephasing and consequently provide contrast enhancement in magnetic resonance imaging (MRI).-The gold nanoparticles and viruses adopt a special kind of crystal structure. It does not correspond to any known atomic or molecular crystal structure and it has previously not been observed with nano-sized particles.-Virus particles -- the old foes of humankind -- can do much more than infect living organisms. Evolution has rendered them with the capability of highly controlled self-assembly properties. Ultimately, by utilising their building blocks we can bring multiple functions to hybrid materials that consist of both living and synthetic matter, Kostiainen trusts.-

Story Source-The above story is based on materials provided by Aalto University. Note: Materials may be edited for content and length.--Journal Reference-Mauri A. Kostiainen, Panu Hiekkataipale, Ari Laiho, Vincent Lemieux, Jani Seitsonen, Janne Ruokolainen, Pierpaolo Ceci. Electrostatic assembly of binary nanoparticle superlattices using protein cages. Nature Nanotechnology, 2012; DOI: 10.1038/nnano.2012.220

Lungs may suffer when certain elements go nano

Missouri University of Science and Technology--Nanoparticles are used in all kinds of applications -- electronics, medicine, cosmetics, even environmental clean-ups. More than 2,800 commercially available applications are now based on nanoparticles, and by 2017, the field is expected to bring in nearly $50 billion worldwide.--But this influx of nanotechnology is not without risks, say researchers at Missouri University of Science and Technology.--"There is an urgent need to investigate the potential impact of nanoparticles on health and the environment," says Yue-Wern Huang, professor of biological sciences at Missouri S&T.--Huang and his colleagues have been systematically studying the effects of transition metal oxide nanoparticles on human lung cells. These nanoparticles are used extensively in optical and recording devices, water purification systems, cosmetics and skin care products, and targeted drug delivery, among other applications.--"In their typical coarse powder form, the toxicity of these substances is not dramatic," says Huang. "But as nanoparticles with diameters of only 16-80 nanometers, the situation changes significantly."--The researchers exposed both healthy and cancerous human lung cells to nanoparticles composed of titanium, chromium, manganese, iron, nickel, copper and zinc compounds [F12]-- transition metal oxides that are on the fourth row of the periodic table. The researchers discovered that the nanoparticles' toxicity to the cells, or cytotoxicity, increased as they moved right on the periodic table.--"About 80 percent of the cells died in the presence of nanoparticles of copper oxide and zinc oxide," says Huang. "These nanoparticles penetrated the cells and destroyed their membranes. The toxic effects are related to the nanoparticles' surface electrical charge and available docking sites."--Huang says that certain nanoparticles released metal ions -- called ion dissolution -- which also played a significant role in cell death.--Huang is now working on new research that may help reduce nanoparticles' toxicity and shed light on how nanoparticles interact with cells.--"We are coating toxic zinc oxide nanoparticles with non-toxic nanoparticles to see if zinc oxide's toxicity can be reduced," Huang says. "We hope this can mitigate toxicity without compromising zinc oxide's intended applications. We're also investigating whether nanoparticles inhibit cell division and influence cell cycle."-The researchers' findings, "Cytotoxicity in the age of nano: The role of fourth period transition metal oxide nanoparticle physicochemical properties," were published in the Nov. 25, 2013, issue of the journal Chemico-Biological Interactions.--Story Source-The above story is based on materials provided by Missouri University of Science and Technology. Note: Materials may be edited for content and length.--Journal Reference-Yue-Wern Huang et al. Cytotoxicity in the age of nano: The role of fourth period transition metal oxide nanoparticle physicochemical properties. Chemico-Biological Interactions, January 2014

Mesoporous silica nanoparticles inhibit cellular respiration.

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Abstract

We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500 microg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM-41 had no noticeable effect on respiration rate. In cells depleted of metabolic fuels, 50 microg/mL SBA-15 delayed the onset of glucose-supported respiration by 12 min and 200 microg/mL SBA-15 by 34 min; MCM-41 also delayed the onset of glucose-supported respiration. Neither SBA-15 nor MCM-41 affected cellular glutathione. Both nanoparticles inhibited respiration of isolated mitochondria and submitochondrial particles

Carbon black particle exhibits size dependent toxicity in human monocytes.

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Abstract

Increased levels of particulate air pollution are associated with increased respiratory and cardiovascular mortality and morbidity. Some epidemiologic and toxicological researches suggest ultrafine particles (<100 nm) to be more harmful per unit mass than larger particles. In the present study, the effect of particle size (nano and micro) of carbon black (CB) [F13]particle on viability, phagocytosis, cytokine induction, and DNA damage in human monocytes, THP-1 cells, was analysed. The cells were incubated with nanosize (~50 nm) and micron (~500 nm) size of CB particles in a concentration range of 50-800 µg/mL. The parameters like MTT assay, phagocytosis assay, ELISA, gene expression, and DNA analysis were studied. Exposure to nano- and micron-sized CB particles showed size- and concentration dependent decrease in cell viability and significant increase in proinflammatory cytokines IL-1 β , TNF- α and IL-6 as well as chemokine IL-8 release. Gene expression study showed upregulation of monocyte chemoattractant protein-1 gene while cyclooxygenase-2 gene remained unaffected. Nano CB particles altered the phagocytic capacity of monocytes although micron CB had no significant effect. CB particles did not show any significant effect on DNA of monocytes. The investigations indicate that CB particles in nanosize exhibit higher propensity of inducing cytotoxicity, inflammation, and altered phagocytosis in human monocytes than their micron size.

SBU-Led Study Reveals Nanoparticles Found in Everyday Items Can Inhibit Fat Storage Increase in gold nanoparticles can accelerate aging and wrinkling, slow wound healing, cause onset of diabetes

STONY BROOK, NY, April 18, 2013 – New research reveals that pure gold nanoparticles found in everyday items such as personal care products, as well as drug delivery, MRI contrast agents and solar cells can inhibit adipose (fat) storage and lead to accelerated aging and wrinkling, slowed wound healing and the onset of diabetes. The researchers, led by Tatsiana Mironava, a visiting assistant professor in the Department of Chemical and Molecular Engineering at Stony Brook University, detail their research, “Gold nanoparticles cellular toxicity and recovery: Adipose Derived Stromal cells,” in the journal Nanotoxicology.

Together with co-author Dr. Marcia Simon, Professor of Oral Biology and Pathology at Stony Brook University, and Director of the University’s Living Skin Bank, a world-class facility that has developed skin tissue for burn victims and various wound therapies, the researchers tested the impact of nanoparticles in vitro on multiple types of cells, including adipose (fat) tissue, to determine whether their basic functions were disrupted when exposed to very low doses of nanoparticles. Subcutaneous adipose tissue acts as insulation from heat and cold, functions as a reserve of nutrients, and is found around internal organs for padding, in yellow bone marrow and in breast tissue.---They discovered that the human adipose-derived stromal cells – a type of adult stem cells – were penetrated by the gold nanoparticles almost instantly and that the particles accumulated in the cells with no obvious pathway for elimination. The presence of the particles disrupted multiple cell functions, such as movement; replication (cell division); and collagen contraction; processes that are essential in wound healing. [F14]--
According to the researchers, the most disturbing finding was that the particles interfered with genetic regulation, RNA expression and inhibited the ability to differentiate into mature adipocytes or fat cells. “Reductions caused by gold nanoparticles can result in systemic changes to the body,” said Professor Mironava. “Since they have been considered inert and essentially harmless, it was assumed that pure gold nanoparticles would also be safe. Evidence to the contrary is beginning to emerge.”[F15] -This study is also the first to demonstrate the impact of nanoparticles on adult stem cells, which are the cells our body uses for continual organ regeneration. It revealed that adipose derived stromal cells involved in regeneration of multiple organs, including skin, nerve, bone, and hair, ignored appropriate cues and failed to differentiate when exposed to nanoparticles. The presence of gold nanoparticles also reduced adiponectin, a protein involved in regulating glucose levels and fatty acid breakdown, which helps to regulate metabolism. ---
“We have learned that careful consideration and the choice of size, concentration and the duration of the clinical application of gold nanoparticles is warranted,” said Professor Mironava. “The good news is that when the nanoparticles were removed, normal functions were eventually restored.”--
“Nanotechnology is continuing to be at the cutting edge of science research and has opened new doors in energy and materials science,” said co-author, Miriam Rafailovich, PhD, Chief Scientist of the Advanced Energy Center and Distinguished Professor of Materials Science and Engineering at Stony Brook. “Progress comes with social responsibility and ensuring that new technologies are environmentally sustainable. These results are very relevant to achieving these goals.”--The research, funded by the National Science Foundation Materials Research Science and Engineering Centers (MRSEC) and Polymer Programs, was a collaboration of Stony Brook University and New York State Stem Cell Science (NYSTEM). The paper was also co-authored by Michael Hadjiargyrou, Professor and Chairperson, Department of Life Sciences at New York Institute of Technology (NYIT) and former Professor in the Department of Biomedical Engineering at Stony Brook.

Nanoparticles that look and act like cells

Camouflaged nanoparticles (yellow) cloaked in the membranes of white blood cells rest on the surface of an immune system cell (phagocyte, blue) without being recognized, ingested, and destroyed.-[F16]-By cloaking nanoparticles in the membranes of white blood cells, scientists at The Methodist Hospital Research Institute may have found a way to prevent the body from recognizing and destroying them before they deliver their drug payloads.[F17] The group describes its "LeukoLike Vectors," or LLVs, in a recent issue of Nature Nanotechnology.--"Our goal was to make a particle that is camouflaged within our bodies and escapes the surveillance of the immune system to reach its target undiscovered," Tasciotti said. "We accomplished this with the lipids and proteins present on the membrane of the very same cells of the immune system. We transferred the cell membranes to the surfaces of the particles and the result is that the body now recognizes these particles as its own and does not readily remove them."--Nanoparticles can deliver different types of drugs to specific cell types, for example, chemotherapy to cancer cells. But for all the benefits they offer and to get to where they need to go and deliver the needed drug, nanoparticles must somehow evade the body's immune system that recognizes them as intruders.[F18] The ability of the body's defenses to destroy nanoparticles is a major barrier to the use of nanotechnology in medicine. Systemically administered nanoparticles are captured and removed from the body within few minutes. With the membrane coating, they can survive for hours unharmed[F19].--"Our cloaking strategy prevents the binding of opsonins -- signaling proteins that activate the immune system," said Department of Medicine Co-Chair Ennio Tasciotti, Ph.D., the study's principal investigator. "We compared the absorption of proteins onto the surface of uncoated and coated particles to see how the particles might evade the immune system response."--Tasciotti and his group took metabolically active leukocytes (white blood cells) and developed a procedure to separate membranes from cell innards. By coating their nanoparticles with intact membranes in their native composition of lipids and proteins, the researchers created the first drug-carrying nanoparticles that look and act like cells -- leukolike vectors[F20].--"Using the membranes of white blood cells to coat a nanoparticle has never been done before," Tasciotti said. "LLVs are half man-made -- the synthetic silicon core -- and half made of man -- the cell membrane."—

"Being able to use synthetic membranes or artificially-created membrane is definitely something we are planning for the future," Tasciotti said. "But for now, using our white blood cells is the most effective approach because they provide a finished product. The proteins that give us the greatest advantages are already within the membrane and we can use it as-is."--As the technology is developed, Tasciotti said a patient's own white cells could be harvested and used to create personalized LLVs. "Cloaked by the patient's own cell membranes, the nanoparticles would be far more likely to reach their targets and avoid the activation of the immune system surveillance," he said. To test whether the LLVs would be protected from macrophage sequestration and destruction, Tasciotti's team tested LLVs coated with human membranes and found that human macrophages left the LLVs unharmed, thus confirming the preservation of the self-recognition principle.--Nanoparticle research has generally focused on getting the particles to recognize specific tissue and to release drugs there, and only there. Comparative studies of LLVs' interaction with healthy and inflamed blood vessel cells showed the LLVs selectively targeted the inflamed tumor blood vessels.--"LLVs are dotted with proteins that help the particles reach specific targets, from inflamed or damaged tissues to cancer cells recruiting blood vessels," Tasciotti said. "Over time the membrane lipids and proteins will break away, leaving the nanoparticles to degrade naturally after releasing their payload."--The research team also looked at how well the drugs traveled through the LLV membrane. They found that rather than introducing an obstacle to drug release, the membrane provides controllable release of the drug once the nanoparticles reach their target tissue.[F21]--The present study used white blood cells from cell cultures. Tasciotti said one of his group's goals is culturing enough cells from the patient to be useful in drug therapy.--"We are aware that we will not always have access to an infinite number of white blood cells," Tasciotti said. "For this reason, we are working to optimize our system by using as little material as efficiently as possible. I expect this technology to become a new player in the crowded world of drug delivery system thanks to the opportunities it offers for the personalization of drug therapies."--Story Source-The above story is based on materials provided by Methodist Hospital, HoustonJournal Reference-Alessandro Parodi, Nicoletta Quattrocchi, Anne L. van de Ven, Ciro Chiappini, Michael Evangelopoulos, Jonathan O. Martinez, Brandon S. Brown, Sm Z. Khaled, Iman K. Yazdi, Maria Vittoria Enzo, Lucas Isenhart, Mauro Ferrari, Ennio Tasciotti. Synthetic nanoparticles functionalized with biomimetic leukocyte membranes possess cell-like functions. Nature Nanotechnology, 2012; 8 (1): 61 DOI: 10.1038/nnano.2012.212

In vitro phototoxicity and hazard identification of nano-scale titanium dioxide.

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Abstract

Titanium dioxide nanoparticles (nano-TiO(2)) catalyze reactions under UV radiation and are hypothesized to cause phototoxicity. A human-derived line of retinal pigment epithelial cells (ARPE-19) was treated with six samples of nano-TiO(2) and exposed to UVA radiation. The TiO(2) nanoparticles were independently characterized to have mean primary particle sizes and crystal structures of 22nm anatase/rutile, 25nm anatase, 31nm anatase/rutile, 59nm anatase/rutile, 142nm anatase, and 214nm rutile. Particles were suspended in cell culture media, sonicated, and assessed for stability and aggregation by dynamic light scattering. Cells were treated with 0, 0.3, 1, 3, 10, 30, or 100μg/ml nano-TiO(2) in media for 24hrs and then exposed to UVA (2hrs, 7.53J/cm(2)) or kept in the dark. Viability was assessed 24hrs after the end of UVA exposure by microscopy with a live/dead assay (calcein-AM/propidium iodide). Exposure to higher concentrations of nano-TiO(2) with UVA lowered cell viability. The 25nm anatase and 31nm anatase/rutile were the most phototoxic (LC(50) with UVA<5μg/ml), while the 142nm anatase and 214nm rutile were the least phototoxic.[F22] An acellular assay ranked TiO(2) nanoparticles for their UVA photocatalytic reactivities. The particles were found to be capable of generating thiobarbituric acid [F23]reactive substances (TBARS) under UVA. Flow cytometry showed that nano-TiO(2) combined with UVA decreased cell viability and increased the generation of reactive oxygen species (ROS, measured by Mitosox). LC(50) values under UVA were correlated with TBARS reactivity, particle size, and surface area.

[F1]Silver Nano Particles

[F2]Morphing the materials to form a different type of material but on a nano scale and the density would also change as well as the means of degradation

[F3]Making a chemical reaction more effective or efficient-and has multiple environmental applications

[F4]The key here would be to break the bound or ligand to separate the ripening of these components

[F5]Interesting play on words it is not saying straight out but it is still harmful ---just not as bad as the other

[F6]Interestingly when copper and zinc combine normally they produce SOD which benefits the body here

[F7]Human Cell Carcinoma Line---so it was not just the mouse but a Human Cell

[F8]So your now getting it in the food supply as well since this does not wash off

[F9]And then when human consumption is occurring how they biotransform us as well this would be a carry over into or DNA andn Genetic structure

Tony

[F10]Nano Particles are in chemtrails and when it rains there might ne good cause to assume these particles are in this synthetic rain

[F11]Morpholgy—the adjusting or restructuring of a polymr

[F12]Which interestingly enough also are in chemtrails

[F13]Carbon black is a form of paracrystalline carbon that has a high surface-area-to-volume ratio, albeit lower than that of activated carbon. It is dissimilar to soot in its much higher surface-area-to-volume ratio and significantly lower (negligible and non-bioavailable

Material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil.

[F14]Normally Gold assist in the regeneration of the body but in a nano format it would appear it does the opposite and this could be because the amount so small and so much concentrates in the cells or tissues that it actually creates a metal overload which the body isunable to resolve due to the concentration and permeation of those areas

[F15]And not just in Gold ---almost all nano metals or minerals when in this scale seem to cause systemic changes and immune system –imepdiments or shut down that would normally occur

[F16]This is alarming when You se the implications here ---with an injection-consumption or a topical you could literally cause a complete re write of the immune system or organ function ---making a condition to rapidly cause a cascading of the bio system ---if the immune system cannot recognize this then what happens isa hijacking of DNA –Chromosoms-or Genetics will occur

[F17]Payload is a good description –the question is of what---if a drug today in the pharma business can cause 30 unwanted side effects---what happens inthis scenario since anything on a nano scale behaves entirely differently and can be rogue in the effect it has?

[F18]Morgellons is a bio/polymer nano that is not recognized by the immune system and hijacks the DNA

[F19]Again this is at best hypothetical since on a nano scale nothing is the same and if the camoflauge is successful enough ---could go undetected and accumulate causing cellular and immune cascading

[F20]Pay attention Here-- leukolike vectors [F20]-"LLVs are half man-made -- the synthetic silicon core -- and half made of man -- the cell membrane."—

So the idea that they will last for a few hours is not accurate---the drug that is being delivered may last a few hours but the delivery mechanism –may withstand for an indefinite period of time

[F21]Controllable release of drug---what about biowarfare??

[F22]Does not mean safe at all just means it was not as lethal

[F23]Thiobarbituric acid reactive substances - TBARS - are formed as a byproduct of lipid peroxidation (i.e. as degradation products of fats) which can be detected by the TBARS assay using thiobarbituric acid as a reagent.