Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Scientists advance safety of nanotechnology

Abstract:
Scientists counteract nanoparticle lung damage in mice

Scientists advance safety of nanotechnology

China | Posted on June 15th, 2009

Scientists have identified for the first time a mechanism by which nanoparticles cause lung damage and have demonstrated that it can be combated by blocking the process involved, taking a step toward addressing the growing concerns over the safety of nanotechnology.

Nanotechnology, the science of the extremely tiny (one nanometre is one-billionth of a metre), is an important emerging industry with a projected annual market of around one trillion US dollars by 2015. It involves the control of atoms and molecules to create new materials with a variety of useful functions, including many that could be exceptionally beneficial in medicine. However, concerns are growing that it may have toxic effects, particularly damage to the lungs. Although nanoparticles have been linked to lung damage, it has not been clear how they cause it.

In a study published online today (Thursday 11 June) in the newly launched Journal of Molecular Cell Biology [1] Chinese researchers discovered that a class of nanoparticles being widely developed in medicine - ployamidoamine dendrimers (PAMAMs) - cause lung damage by triggering a type of programmed cell death known as autophagic cell death. They also showed that using an autophagy inhibitor prevented the cell death and counteracted nanoparticle-induced lung damage in mice.

"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," said the study's leader, Dr. Chengyu Jiang, a molecular biologist at the Chinese Academy of Medical Sciences in Beijing, China.

The first nanomaterial was developed by German scientists in 1984. Nanomaterials are now used in a variety of products, including sporting goods, cosmetics and electronics. The fact that unusual physical, chemical, and biological properties can emerge in materials at the nanoscale makes them particularly appealing for medicine. Scientists hope nanoparticles will be able to improve the effectiveness of drugs and gene therapy by carrying them to the right place in the body and by targeting specific tissues, regulating the release of drugs and reducing damage to healthy tissues. They also envision the possibility of implantable nano devices that would detect disease, treat it and report to the doctor automatically from inside the body. The US Food and Drug Administration has approved some first generation nanodrugs. One example is Abraxane, a nanoformulation of the anti-cancer chemotherapy paclitaxel.

Lung damage is the chief human toxicity concern surrounding nanotechnology, with studies showing that most nanoparticles migrate to the lungs. However, there are also worries over the potential for damage to other organs.

In the study, the researchers first showed, through several independent experiments, that several types of PAMAMs killed human lung cells in the lab. They did not observe any evidence that the cells were dying by apoptosis, a common type of programmed cell death. However, they found that the particles triggered autophagic cell death through the Akt-TSC2-mTOR signalling pathway. Autophagy is a process that degrades damaged materials in a cell and plays a normal part in cell growth and renewal, but scientists have found that sometimes an overactivity of this destruction process leads to cell death.

The researchers also found that treating the cells with an autophagy inhibitor known as 3MA significantly inhibited the process, increasing the number of cells that survived exposure to the nanoparticles.

"Those results, taken together, showed that autophagy plays a critical role in the nanoparticle-induced cell death," said Dr. Jiang.

The scientists then tested their findings in mice. They found that introducing the toxic nanoparticles significantly increased lung inflammation and death rates in the mice, but injecting the mice with the autophagy inhibitor 3MA before introducing the nanoparticles significantly ameliorated the lung damage and improved survival rates.

"These experiments indicate that autophagy is indeed involved in lung damage caused by these nanoparticles and that inhibition of this process might have therapeutic effects," Dr. Jiang said. "We will likely need to look for additional new inhibitors to block lung damage as this particular compound is not stable in humans, but this gives us a promising lead for the first time."

"Our study has identified the principle for developing such compounds. 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. Jiang said, adding that the findings could also provide important insight into how nanopaticles cause other toxic effects.

It is not clear whether other types of nanoparticles would cause lung damage via the same mechanism, but some may, Dr. Jiang said. The group's research also suggests that blocking autophagic cell death could perhaps be useful in combating other causes of lung damage.

[1] PAMAM nanoparticles promote acute lung injury by inducing autophagic cell death through the Akt-TSC2-mTOR signalling pathway. Journal of Molecular Cell Biology. doi:10.1093/jmcb/mjp002

Notes:

The Journal of Molecular Cell Biology is published by Oxford Journals, a division of Oxford University Press, on behalf of the Chinese Academy of Sciences and the Chinese Society for Cell Biology.

Please acknowledge the journal as a source in any article.

####

About Oxford University Press
Oxford Journals is a division of Oxford University Press, which is a department of Oxford University. We publish well over 200 academic and research journals covering a broad range of subject areas, two-thirds of which are published in collaboration with learned societies and other international organizations.

For more information, please click here

Contacts:
Emma Ross

Oxford University Press

Copyright © Eurekalert

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Aculon Hires New Business Development Director December 19th, 2014

Preparing for Nano

Durnham University's DEEPEN project comes to a close September 26th, 2012

Technical Seminar at ANFoS 2012 August 22nd, 2012

Nanotechnology shows we can innovate without economic growth April 12th, 2012

Thailand to host NanoThailand 2012 December 18th, 2011

Nanomedicine

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

Iranian Researchers Produce Electrical Pieces Usable in Human Body December 18th, 2014

Unraveling the light of fireflies December 17th, 2014

First Home-Made Edible Herbal Nanodrug Presented to Pharmacies across Iran December 17th, 2014

Announcements

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Aculon Hires New Business Development Director December 19th, 2014

Safety-Nanoparticles/Risk management

Nutrition, Safety Key To Consumer Acceptance of Nanotech, Genetic Modification In Foods December 2nd, 2014

Sustainable Nanotechnologies Project November 20th, 2014

A gut reaction November 19th, 2014

Nanosafety research – there’s room for improvement October 29th, 2014

Nanobiotechnology

Scientists trace nanoparticles from plants to caterpillars: Rice University study examines how nanoparticles behave in food chain December 16th, 2014

FEI and Oregon Health & Science University Install a Complete Correlative Microscopy Workflow in Newly Built Collaborative Science Facility December 16th, 2014

UCLA engineers first to detect and measure individual DNA molecules using smartphone microscope December 15th, 2014

Biomimetic dew harvesters: Understanding how a desert beetle harvests water from dew could improve drinking water collection in dew condensers December 8th, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE