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Nanoparticle May Cause Lung Cancer

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The fledgling science of nanotechnology promises huge advances in science and medicine, but there are concerns about its safety.

In particular, the microscopic particles it employs have been shown to have toxic effects on the lungs.

The research, by the Chinese Academy of Medical Sciences, appears in the Journal of Molecular Cell Biology.

However, experts said it was not possible to draw general conclusions about all nanoparticles from a study focusing on one specific type.

Nanotechnology involves the modification of atoms and molecules to create new materials which may have unusual physical, chemical, and biological properties.

“This provides us with a promising lead for developing strategies to prevent lung damage caused by nanoparticles” says Chengyu Jiang, Chinese Academy of Medical Sciences

In medicine alone it is hoped it could be used to develop more effective and better targeted drugs, and new ways to detect and treat disease.

The market is potentially huge, but safety concerns threaten to hold progress back.

Research has shown that most nanoparticles migrate to the lungs, but there is also concern about potential damage to other organs.

The latest research focused on a class of nanoparticles being widely developed in medicine – polyamidoamine dendrimers (PAMAMs).

In tests on cells in the lab, the researchers found the particles cause lung damage by triggering a type of programmed cell death known as autophagic cell death.

Autophagy plays a normal part in cell growth and renewal, but over-activity can lead to unwanted cell death.

However, the researchers also found autophagy could be blocked by using a drug inhibitor.

The findings were confirmed in tests on mice. Animals exposed to PAMAMs showed higher levels of lung inflammation, and higher death rates.

But those that were first injected with the inhibitor were less badly affected.

New strategies
Lead researcher Dr Chengyu Jiang said: “This provides us with a promising lead for developing strategies to prevent lung damage caused by nanoparticles.

Nanomedicine holds extraordinary promise, particularly for diseases such as cancer and viral infections.

“But safety concerns have recently attracted great attention and with the technology evolving rapidly, we need to start finding ways now to protect workers and consumers from any toxic effects that might come with it.”

“The idea is that, to increase the safety of nanomedicine, compounds could be developed that could either be incorporated into the nano product to protect against lung damage, or patients could be given pills to counteract the effects.”

Dr Laura Bell, of the charity Cancer Research UK, said: “It’s great to see new advances being made to ensure the safety of nanomedicine but this research is still at an early stage and has yet to be tested in people.

“Nanotechnology is an expanding area of research with exciting potential and establishing its safety is essential if we are to realise its potential to treat people with cancer.”

It is not clear at this stage whether other types of nanoparticles cause lung damage via the same route.

Professor Ken Donaldson, an expert in respiratory toxicology at the University of Edinburgh, said PAMAMs were highly specialised, and it would be wrong to draw any general conclusions about nanoparticles in general from the study.

Professor Donaldson said PAMAMs were made by the drug industry in tiny amounts, while other nanoparticles were made in much bigger quantities, and potentially posed much more of a risk of accidental exposure.

He said: “The problem is that all nanoparticles are lumped together as if they are one thing and they most certainly are not.”

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Source:
BBC NEWS:11Th. June,’09

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Sunny Side Down

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SUNSCREEN  CREAM MAY CAUSE SERIOUS DAMAGE TO SKIN CELLS:- 

Do people get more than what they ask for when they apply the new generation sunscreens to protect their skin from the blistering sun? The question that has echoed several times in the past one decade may not have a clear answer as yet with the pendulum swinging in both directions. But a recent study, by a team of researchers from the Indian Institute of Toxicology Research (IITR), in Lucknow, has some disturbing accounts to reveal.

The scientists from IITR (formerly Industrial Toxicology Research Centre), led by Alok Dhawan, found that a material, used in the nanoparticle form in some of the sunscreens hitting the market in the recent past can actually interfere with DNA present in the skin cells. Such changes can even lead to cancer. “The material — zinc oxide — otherwise a benign substance, seems to trigger some changes in the genetic material present in skin cells when it is in nanoparticle form,” said Dhawan. He was quick to add that the tests have been conducted only on laboratory human skin cells and that his team has not yet studied its effects on a living person.

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Sunscreens use either zinc oxide or titanium dioxide as the principal ingredient as both the substances possess the ability to scatter visible light — the primary objective of the cream, quite commonly used by sports personnel such as cricketers. In the conventional form, both the materials have a serious drawback: they remain as white patches on the skin. This disadvantage can be tackled by reducing the particle size. When they are smaller than 100 nanometres (one nanometre is one billionth of a metre), they don’t leave any mark on the skin and yet retain the sun-blocking property. “Such nanoparticles are 10 to 12 times smaller than a human skin cell and can easily penetrate,” explained Dhawan.

Nanoparticles — a million times smaller than a pinhead — are being hailed as the promise of the future. They are expected to revolutionise a number of fields, ranging from agriculture to health care to industry. They can find applications in drug delivery, cosmetics, electronics, textiles and many others. Many of these applications have progressed beyond the research stage.

However, there are conflicting reports about the adverse effects. Regulatory agencies, including those in the 21 countries that have cleared manufacturing and selling nanoparticle-based consumer products, are not absolutely clear about the toxic potential of these nanoparticles. For instance, US Environmental Protection Agency (EPA) periodically reviews new studies available on nanotechnology materials to assess their safety with regard to human health as well as the environment.

“There are unanswered questions about the impacts of nanomaterials and nanoproducts on human health and the environment,” EPA said in its last Nanotechnology White Paper released in 2007.

On the other hand, in a 2006 review specifically on zinc oxide nanoparticles-based sunscreens, Therapeutic Goods Administration (the Australian regulator) concluded, “There is evidence from isolated cell experiments that zinc oxide and titanium dioxide can induce free radical formation in the presence of light and that this may damage these (skin) cells. However, this would only be of concern in people using sunscreens if the zinc oxide and titanium dioxide penetrated into viable skin cells. The weight of current evidence is that they remain on the surface of the skin and in the outer dead layer of the skin.”

The IITR study, however, has shown that even at low concentration zinc oxide nanoparticles can penetrate the outer layer of the skin.

According to Dhawan, the problem with current toxicology studies of nanoparticles is that most research groups test the materials on rat or mice skin. “These rodent skins are 10 times denser than the human skin, and hence the chances are lesser that the tiny particles could pass through,” he told KnowHow.

Besides, many studies have used the sun block creams in much higher concentration. As a result the pasted cream itself created a barrier to skin entry.

Dhawan said he, as a scientist, is not against using nanoparticles. “All I would say is, proper clinical trials should be conducted before they are allowed to enter the market.”

For him, caution is the key word when it comes to the use of nanoparticles in consumer products.

Sources: The Telegraph (Kolkata, India)

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Are Nanofoods the Next Consumer Nightmare?

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Consumers already worried about genetically engineered or cloned food may soon find another worry in their grocery carts: nano-foods.

Nanotechnology involves the design and manipulation of materials on molecular scales. Companies using nanotechnology say it can enhance the flavor or nutritional effectiveness of food. Food produced by using nanotechnology is quietly coming onto the market, and consumer groups want U.S. authorities to force manufacturers to identify them.

U.S. health officials generally do not place warning labels on products unless there are clear, known reasons for caution or concern. But consumer advocates say uncertainty over health consequences alone is sufficient cause to justify identifying nano-foods.

Sources:
Reuters July 30, 2008

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Are Nano-Foods the Next Scary Items?

Those consumers already worried about genetically engineered or cloned food reaching their tables may soon find something else in their grocery carts to furrow their brows over – nano-foods.

..

Consumer advocates taking part in a food safety conference in Orlando, Florida, this week said food produced by using nanotechnology is quietly coming onto the market, and they want US authorities to force manufacturers to identify them.

Nanotechnology involves the design and manipulation of materials on molecular scales, smaller than the width of a human hair and invisible to the naked eye. Companies using nanotechnology say it can enhance the flavor or nutritional effectiveness of food.
US health officials generally prefer not to place warning labels on products unless there are clear reasons for caution or concern. But consumer advocates say uncertainty over health consequences alone is sufficient cause to justify identifying nano-foods.

“I think nanotechnology is the new genetic engineering. People just don’t know what’s going on, and it’s moving so fast,”Jane Kolodinsky, a consumer economist at the University of Vermont, said at the conference.

American consumers are generally more complacent about genetically modified or cloned foods than their counterparts in Europe. But Michael Hansen, a senior scientist with the Consumers Union, said polls show that 69% of Americans are concerned about eating cloned meat.

He said that in focus groups run by the US Food and Drug Administration, no parents were willing to feed their children meat from cloned animals or their offspring.

New consumer products created through nanotechnology are coming on the market at the rate of 3 to 4 per week, according to an advocacy group, The Project on Emerging Nanotechnologies (PEN), based on an inventory it has drawn up of 609 known or claimed nano-products.

Nano-products in common use today include lightweight tennis rackets and bicycles, and sunscreens containing clear, nonwhite versions of zinc oxide and titanium dioxide. On PEN’s list are three foods – a brand of canola cooking oil called Canola Active Oil, a tea called Nanotea and a chocolate diet shake called Nanoceuticals Slim Shake Chocolate.

Sources
: The Times Of India

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