12/8/13
12/8/13 0
8/3/12
Research
Researchers at Trinity College Dublin's School of Medicine have investigated whether there is a common underlying mechanism contributing to the development of autoimmune diseases in human cells due to the exposure nanoparticles.
The researchers applied nanomaterials such as ultra fine carbon black, carbon nanotubes and silicon dioxide particles of different sizes to human cells derived from the lining of the airway passages, and to the cells that are most frequently exposed to the inhaled foreign particles and in mice exposed to chronic inhalation of air contaminated with single walled carbon nanotubes.
Findings
They found that all types of nanoparticles were causing an identical response in human cells and in the lungs of mice, resulting in specific transformation of the amino acid arginine into the molecule called citrulline which can lead to the development of autoimmune conditions such as rheumatoid arthritis.
In the transformation to citrulline, human proteins which incorporate this modified amino acid as building blocks, can no longer function properly and are subject to destruction and elimination by the bodily defense system. Once programmed to get rid of citrullinated proteins, the immune system can start attacking its own tissues and organs, thereby causing the autoimmune processes which may result in rheumatoid arthritis.
Applications
The research establishes a clear link between autoimmune diseases and nanoparticles. Preventing or interfering with the resulting citrullination process looks therefore as a promising target for the development of future preventative and therapeutic approaches in rheumatoid arthritis and possibly other autoimmune conditions.
8/3/12 0
6/7/12
He was arrested recently because he allegedly stole laboratory research and shared it with China.He is being accused of stealing research belonging to the U.S. that he claimed was his own original research. He allegedly shared with several Chinese universities and went online to share the data with the country’s state-run schools including Peking University and the Harbin Institute of Technology. But Sandia National Labs says that he did not have access to classified national security information. Huang was fired in April for removing a company-owned laptop from the facility.
Sandia, a subsidiary of Lockheed Martin Corporation is known for its nuclear research, as well as the disposal of the U.S. nuclear weapons program’s hazardous waste and focusing on nanotechnology for the past five years.Lab workers are not allowed to take any lab equipment on international trips without approval. Huang started working on nanotechnology at a Sandia Labs research center and has been indicted on five counts of federal program fraud, and one count of false statements, according to court papers which fact was made known only recently. He is accused of embezzling and sharing information from his position with the lab's Center for Integrated Nanotechnologies since 2009, according to a federal indictment.He will be arraigned on the charges Tuesday, and remains in federal custody.
Jianyu Huang has pleaded not guilty to charges of stealing research to share with China. It is to be noted that Buckyball birth was observed by Sandia CINT researcher Jianyu Huang.
6/7/12 0
6/14/11
Nanosilver products
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6/14/11 0
4/26/11
Nanotechnology is used to treat human body through the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications and drug delivery vehicles. In most applications, nanoparticles are coated with a layer of molecules, often proteins, which determine the use of nanoparticles when they enter cells. In a wide range of cells nanoparticles are taken into inner region of cell where this essential coating is degraded to work against the disease.Scientists have uncovered what happens to nanoparticles when they enter human cells. They found that the important proteins that make up the outer layer of these nanoparticles are degraded. But scientists have to still understand this phenomenon. Scientists at the University of Liverpool think say that they do not know what state they are in by the time they get there.
The design of any intracellular nanodevice must now take into account the possibility of cathepsin L degradation and either bypass the endosome area all together or have some built-in inhibition of the enzyme. Researchers have developed methods to measure the location and the state of the nanoparticle quickly and quantitatively.
4/26/11 0
1/12/11
Nanomaterials
Quantum dots which are nanosized semi-conductors that generate electron-hole pairs confined in all three dimensions (quantum confinement) behave like giant molecules rather than bulk semiconductors. Quantum dots are widely used in light emitting diodes, transistors, solar cells, drug delivery, cancer therapy and cell imaging. But most quantum dots contain highly toxic metals such as cadmium, which tends to be released when they enter the cells or organisms. Many kinds of nanoparticles enhance the formation of insoluble fibrous protein aggregates (amyloids), which are associated with human diseases including Alzheimer’s, Parkinson’s and Creutzfeld-Jacob disease.
Obviously not all nanoparticles are harmful, but exhaustive tests are needed to ascertain the ill effects of the engineered nanoparticles. It is clear from the above evidence that an urgent action research is needed not only to stem but also to reverse the unregulated tide of nanoparticles that are released into the market.
The above existing evidences require the following actions.
- Nano-ingredients in food, cosmetics and baby products such as silver, titanium oxide, fullerenes etc., for which toxicity data already exist should not be allowed to be used.
- Nano-products should not be commercialized until they are demonstrated safe and obey regulations.
- Consumer products containing nanotechnology should be clearly labeled about the amount of nanomaterial content.
- Manufacturers of nano-products should properly register their products to the appropriate authorities and make it public without keeping secret.
- Nanotechnology research activities must be made comprehensible to the public performed in a transparent manner, accountable, safe and sustainable, and not pose a threat to the environment.
- Intensive research into the hazards of nanotechnology should also be carried out in equal proportion to the new commodity development.
1/12/11 0
1/7/11
Nano-silver, even more widely used than nano-TiO2, is toxic to beneficial bacteria that break down wastes and recycle nutrients in the soil.Fullerenes, which finds applications in electronics, electro-optics and much more besides, including cosmetics are being considered for drug delivery and cancer therapy also.
Quantum dots are nanosized semi-conductors that generate electron-hole pairs confined in all three dimensions (quantum confinement), and hence behave like giant molecules rather than bulk semiconductors. They have numerous applications in light emitting diodes, transistors, solar cells etc., and are also being developed for drug delivery, cancer therapy and cell imaging. Unfortunately, most quantum dots contain highly toxic metals such as cadmium, which tends to be released when the quantum dots enter the cells or organisms. This was thought to be the main reason why CdSe/ZnSe quantum dots at nanomolar (10-9mol) concentrations were toxic to Daphnia magna, but much less toxic than the equivalent concentration of cadmium ions. However, CdTe quantum dots coated with hydrophilic sodium thioglycolate caused disruption in a cultured monolayer of Caco-2 human intestinal cells and cell-death at 0.1 ppm, which was thought to be caused by the quantum dots, rather than cadmium. In another study, CdSe/ZnS quantum dots injected intravenously into mice caused marked vascular thrombosis in the lungs at 0.7 to 3.6 nanomol per mouse, especially when the quantum dots had carboxylate surface groups. Three out of four mice injected at the higher concentration died immediately. The injected quantum dots were mainly found in the lungs, liver and blood; and it was hypothesized that the quantum dots activated the coagulation cascade through contact. In fact, many kinds of nanoparticles enhance the formation of insoluble fibrous protein aggregates (amyloids), which are associated with human diseases including Alzheimer’s, Parkinson’s and Creutzfeld-Jacob disease.
1/7/11 0
Plants and microbes can absorb nano-sized synthetic particles that increase in concentration within predators up the food chain, according to two studies.
Getting into food chain
Nanoparticles are used in hundreds of consumer products ranging from transparent sunscreens to odor free socks. From there when they get washed down the drains, ultimately end up in the sewage sludge of wastewater treatment plants. Sice several million tons of dried-out sludge is subsequently mixed into agricultural soil each year, there is possibility of nanoparticles to go into the food chain in this way.
Nanoparticles
Synthetic nanoparticles made of silver, titanium dioxide, zinc oxide and other substances due to their small size and stability; they can nullify odors, prevent food spoilage and absorb harmful ultraviolet radiation, among other feats. But knowledge about their impacts to the environment is still in a state of infancy.
Experiments
To explore nanoparticle absorption in the food chain, researchers at University of Kentucky raised tobacco plants in a hydroponics greenhouse. While the plants grew, the researchers added super-stable gold nanoparticles to the water to mimic consumer nanoparticles in wastewater sludge. Gold nanoparticles built up in tobacco leaf tissue, and tobacco hornworms that ate the plants accumulated concentrations of the nanomaterials about 6 to 12 times higher than in the plant.
Predatory microbes in a separate study also built up concentrated levels of cadmium selenide nanoparticles after eating smaller microbes that ingested them.
Researchers at the University of Delaware have provided an experimental evidence that plants can take up nanoparticles and accumulate them in their tissues. The laboratory study, which involved pumpkin plants, indicates a possible pathway for nanoparticles to enter the food chain. The research also reveals a new experimental approach for studying nanoparticles and their potential impacts. The researchers chose pumpkins for the study because they take in a lot of water and are easy to grow. The plants were grown hydroponically in an aqueous medium to which nanoparticles of iron oxide, or magnetite, a magnetic form of iron ore, were added. After 20 days of growth, the plants were cut into pieces and dried in a vacuum dessicator. A magnetometer was then used to detect if any of the particles had been absorbed by the plant. The magnetometer subjected the dried pumpkin plants to a low-frequency monotone to vibrate them. The vibration revealed each tiny particle of magnetite's unique magnetic signal and, thus, exact location inside the plant.Thus magnetic nanoparticles can be taken up, translocated and accumulated in pumpkin plants.
Regulation
At least five government agencies (EPA, FDA, NIH, NIOSH and NIST) host efforts to investigate nanotechnology’s risks to health and the environment, and their funding is increasing each year. And while heavy metals and other toxins in sludge are federally regulated, manmade nanoparticles are not. That may cause concern as farms increasingly mix sludge into their soils, where nanoparticles may build up over time.There is some evidence that nanoparticles are toxic under lab-controlled conditions, but realistically assessing risks to health and the environment demands more advanced research efforts.
1/1/11
Nanophobia is the fear that nanomaterials used in one way or other can harm the body. This is based on the fear that as tiny nanoparticles can travel through tissue along blood vessels in the human body. If the nanoparticles are indestructible and accumulate in the organs and are not metabolized the organs may fail.
One school of scientists and consumer advocates claim that many industries are adopting nanotechnology ahead of studies that have not yet proved whether regular ingestion, inhalation or dermal penetration of nanoparticles constitute a health or environmental hazard.
Nanotechnology incorporated products are already in the market and people are already exposed to nanoparticles. For example stoves and toaster ovens emit ultrafine particles of 2 to 30 nanometers size and researchers reporte that long-term contact with such appliances could constitute a large exposure to the nanoparticles.
There are products like nano pants, stain-resistant chinos and jeans whose fabric contain nano-sized whiskers that repel oil and dirt, and nanocycles made from carbon nanotubes that are stronger and lighter than standard steel bicycles, lotions and creams which use nanocomponents that may create a more cosmetically elegant effect.
In beauty products dynamic nanoparticles could pose risks to the skin or, if they penetrate the skin, to other parts of the body. The personal care products that contain nano-size components constitute a health hazard as it is also reported that exposure to nanoparticles of titanium dioxide cause damage to the organs of laboratory animals and human cell cultures.
This being an argument, no rigorous clinical trials have been published showing that cosmetics with nanocomponents caused health problems as it is very difficult to get anything through the skin which is an very effective barrier.
Nanotechnology has enormous potential to do a lot of good for mankind. There are recent reports that sunscreens, which contain nanoparticulate titanium dioxide or zinc oxide, which blocks out harmful UV radiation, are being sold as nanofree. These have been tested, to show that they pose no danger, as the nanoparticles, although small, are too large to penetrate the dermal layer. However, this is not projected in right sense, which unfortunately can often base articles on pseudo-science. However there is an important responsibility for the scientists to quantify any risk that may be involved, and report whether it is safe to use such materials.
1/1/11 0
12/18/10
12/18/10 0
10/18/10
Virginia Polytechnic Institute & State University researchers found silver in the Sludge from a typical wastewater treatment plant using x-ray transmission electron microscopy, an extremely sensitive technique that can identify both composition and structure. With micrographs of sludge they identified nanoparticles 5 to 20 nm in diameter and determined that the particles had a 2-to-1 silver-to-sulfur ratio. The scientists also obtained a crystal structure to confirm that the particles were Ag2S. This is because wastewater plants contain high concentrations of sulfide and so silver readily binds to sulfur. The conversion of silver to silver sulfide within waste treatment plants may be good for the environment, but it is feared that these materials could still enter the ecosystem via animals who consume particles in the sludge, clearly giving a warning signal on the excessive use of silver nanoparticles.
10/18/10 0
10/5/10
Carbon nanotubes come in many different forms and purities. They range from flexible, thin, few-walled or single-walled nanotubes (SWNTs, typically short (less than 5 micron in length), very specialized, high molecular weight fullerene nanotubes which have single or very few walls to rigid, long, thick, multi-walled nanotubes (MWNTs, typically long (greater than 10 micron), with a spectrum of characteristics and properties in-between with fibril structures with a high concentration of defects and little tendency to rope and tangle. Many of the nanotubes marketed by are incorporated into transparent conductive films for the display and touch panel industries. nanotubes are sold to select customers as powders and in suspensions in liquids, also called inks.
Public safety
Due to difficulty in safe-handling requirements these materials, manufacturers do not sell nanotubes directly to the public and the consumer products containing nanotubes have minimal risk of exposure because the nanotubes are bound in polymeric solid or film, isolated from the consumer and environment. The customers for ink and powder products are companies and research institutions that use the nanotubes as a component in a final product. All customers that purchase nanotube products receive the appropriate Materials Safety Data Sheet (MSDS) for the product. The MSDS details the currently accepted best practices for personal protective equipment and outlines safe handling practices for nanomaterials.
Industrial safety
The chemical industries adopt well-established procedures for protecting workers who are handling nanotube powders of unknown toxicity with protective equipment provides adequate safe handling protection. of course carbon nanotube products can be safely managed with engineering controls such as closed reactor systems, hoods, and mechanical ventilation systems. Waste materials resulting from the manufacture of nanotubes are disposed of in accordance with regulations.
10/5/10 0
9/15/10
Nanoparticles in various forms are now incorporated in more than 1000 commercial products including textiles, conductive inks, solar cells, personal care products, medical devices, cosmetics, appliances, and baby products. This creates a situation that users will be in contact with nanomaterials someway on a frequent and long-term basis during their day to day activities. While the benefits of nanomaterials have been well recognized, there is concern that some nanotechnology enabled products may pose a risk to the environment and human health at some point in their life cycle. Some researchers also suggest that nanomaterials are potentially more toxic and dangerous than their bulk counterparts. Hence it is important to predict and measure the health impacts and environmental implications of nanomaterials.Apart while using nanotechnology enabled products, exposure to nano materials takes place at production and processing level. The ways of primary exposure of nanomaterials is through aerosolization and inhalation. Aerosolization can occur during synthesis, production, handling and processing of nanomaterials at the level of manufacturing stage.
When drying nanoparticle suspensions for the development of nano composits, the process can maximize the aerosolizability of the material. Exposure through inhalation can occur when dealing with powdered materials. For example, spray drying of nanoparticles for coatings, production of powdered materials, and the preparation of nano composite materials could result in exposure to nanoparticles through inhalation.
In the industrial production, a custom aerosol chamber is used. This chamber is equipped with pneumatic, venturi, and burst disk launch mechanisms that disseminate nanomaterials with different shear forces and creates nanoparticle clouds with various densities, average sizes, and aggregation levels. Quantification of the potential exposure risk and hazard of handling different types of nanomaterials is done by instrumenting and monitoring in real-time basis the particle counts, size distributions of aerosolized particles and aggregates in the size regime of 5-15,000 nm, identifying mass loadings, and measuring the optical properties like absorption, scattering, and extinction at wavelengths from400 nm to 20 microns.
Further while under long storage, the nanomaterials are batched and monitored with time to ensure that storage has not altered their properties. Materials of interest include various forms of carbon like C60, nanotubes, graphite, etc. other metals like copper, manganese, iron, palladium, etc.,metal oxides like TiO2, Fe2O3, CeO2, ZrO, etc., ceramics, and semiconductor nanoparticles. Tools utilized to understand changes to the surface of the nanoparticles include isoelectric point, matrix aided laser desorption ionization mass spectrometer (MALDI-MS), Fourier Transform Infrared Spectroscopy (FTIR), and Raman spectroscopy.
9/15/10 0
9/13/10
Carbon nanotubes consist of molecular cylinders of pure, hexagonally-arranged carbon atoms with a diameter measuring a few nanometres and a length of many microns. They occur in two main types, the single-wall carbon nanotube composed of a single cylinder of carbon and the multi-wall version consisting of concentric tubes or cylinders of carbon. But very little fact is known about how these nanomaterials affect the environment, since some researchers indicate that one class of SWNTs produces cell-damaging reactive oxygen species (ROS) when dispersed in water and exposed to sunlight.
ROS are chemically-reactive molecules containing oxygen such as oxygen ions and peroxides. They are highly reactive due to the presence of unpaired valence shell electrons. ROS can result in significant damage to cell structures and cumulates into a situation known as oxidative stress. Reactive oxygen species are implicated in cellular activity to a variety of inflammatory responses including cardiovascular disease. They may also be involved in hearing impairment via cochlear damage induced by elevated sound levels, ototoxicity of drugs such as cisplatin, and in congenital deafness in both animals and humans. Redox signaling is also implicated in mediation of apoptosis or programmed cell death, ischaemic injury and can oxidize and damage an organism's DNA, lipids and proteins. Specific examples include stroke and heart attack.
Large quantities of CNTs are produced, used and disposed globally in industries and research labs and hence it should be known how they are transformed in the environment and whether their products are more or less harmful than the parent materials.
Simulated environmental exposure studies revealed that by shining natural sunlight on glass tubes filled with carboxylated SWNTs suspended in water, after 80 hours with carboxylated swnts produced ROS. Similarly, SWNTs when suspended in acidic water and irradiated, clumped together and came out of suspension as aggregate, thus getting chemically altered in composition. This could be toxic to aquatic organisms when they come in contact with water body of the environment.
However it has been known that cells are normally able to defend themselves against ROS damage with a host of enzymes. Small molecule antioxidants such as ascorbic acid (vitamin C), tocopherol (vitamin E), uric acid, and glutathione also play important roles as cellular antioxidants. Similarly, polyphenol antioxidants assist in preventing ROS damage by scavenging free radicals. Intensive research is going on to understand how toxicity of these engineered materials will affect the environment when they are released.
9/13/10 0
9/7/10
Read the following interesting, concise and relevant account on the effect of exposure of nano materials on human body presented as such.As with all chemical manufacturing processes, production of NPs may give rise to exposure by inhalation, through the skin and by ingestion. Exposure may also occur for workers in downstream processes that use these materials and to consumers as these products enter the market-place. In gas-phase production processes, exposure by inhalation may be caused by direct leakage of the reactants or products into workplace air. For all production methods, product recovery, subsequent processing and cleaning may result in the generation of airborne NPs. It is, however, probable that these downstream activities will not generate discrete NPs, due to the relatively high energies, which would be necessary to break the forces which keep particles agglomerated. However, exposure to agglomerated NPs may also pose a significant risk to health. All the production processes described could potentially result in dermal exposure, particularly at the powder handling, packaging and bagging stages. It has been postulated that NP exposure to the skin may result in direct penetration, although currently there is little evidence to support this. Several pharmaceutical companies are, however, developing drug delivery systems based on topical application NPs. Dermal exposure is likely to result in ingestion exposure from hand-to-mouth contact. Typically, airborne exposures in the workplace are assessed in terms of mass concentration. Current evidence suggests that the most appropriate metric for exposure by inhalation for NPs is surface area. This appears to fit best with current toxicological evidence relating to mechanisms of harm. It would also address directly the issue of agglomeration. Ideally a personal sampler should be available which could assess this metric. However, none currently exists. For those NPs that could be considered as fibers, such as CNTs, particle number may be a more appropriate metric than surface area. In any case, it is also necessary to consider characterizing exposures against aerosol mass and number concentration until further information and improved methods are available. For each of these exposure metrics, but particularly in the case of mass concentration, size-selective sampling will need to be employed to ensure only particles within the relevant size range are sampled. For dermal exposure, measurements should also be biologically relevant. At this stage, there is insufficient evidence to indicate whether mass, number or surface area is the most appropriate metric. Measurement approaches should ideally also consider the skin area exposed and the duration of exposure. For ingestion exposure too, measurements should also be biologically relevant. There is insufficient evidence to indicate what the most appropriate metric is. Information about the exposure of workers to NPs is very limited. None has been identified about exposures in the university/research sector or in the new NP companies. Very limited information is available on existing chemical, pharmaceutical and refining companies. Either mass or number is used as an exposure metric, rather than surface area. The number-based estimates are derived from static samplers rather than personal samplers. Information from other powder-handling processes indicates that exposures may be significant. There is a clear need to collect more information about exposure to NPs in both manufacturing and user scenarios. Production quantities are still relatively small. As products grow in both number and volume, and as manufacturers switch process from the micro- to the nanoscale, the potential for exposure will clearly increase. Much more information is needed to quantify any risks to workers or consumers.
Source: R. J. Aitken, M. Q. Chaudhry, A. B. A. Boxall and M. Hull. Manufacture and use of nanomaterials: current status in the UK and global trends, Occupational Medicine 2006;56:300–306 doi:10.1093/occmed/kql051
9/7/10 0
9/19/08
Health risksThe incorporation of manufactured nanomaterials into foods and beverages, nutritional supplements, food packaging, and edible food coatings, fertilisers, pesticides and comprehensive seed treatments presents a whole new array of risks for the public, workers in the food industry and farmers.A growing body of evidence demonstrates that some manufactured nanoparticles will be more toxic per unit of mass than larger particles of the same chemical composition. For example, titanium dioxide is considered to be biologically inert in bulk form and is widely used as a food additive. However, in vitro experiments show that as a nanoparticle or particle up to a few hundred nanometres in size, titanium dioxide damages DNA, disrupts the function of cells, interferes with the defence activities of immune cells, and can provoke inflammation. A single high oral dose of titanium dioxide nanoparticles can cause significant lesions in the kidneys and livers of female mice.
9/19/08 0
