Featured Research

from universities, journals, and other organizations

Health Risks Of Nanotechnology: How Nanoparticles Can Cause Lung Damage, And How The Damage Can Be Blocked

Date:
June 11, 2009
Source:
Oxford University Press
Summary:
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.

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 June 11 in the newly launched Journal of Molecular Cell Biology 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.


Story Source:

The above story is based on materials provided by Oxford University Press. Note: Materials may be edited for content and length.


Journal Reference:

  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

Cite This Page:

Oxford University Press. "Health Risks Of Nanotechnology: How Nanoparticles Can Cause Lung Damage, And How The Damage Can Be Blocked." ScienceDaily. ScienceDaily, 11 June 2009. <www.sciencedaily.com/releases/2009/06/090610192431.htm>.
Oxford University Press. (2009, June 11). Health Risks Of Nanotechnology: How Nanoparticles Can Cause Lung Damage, And How The Damage Can Be Blocked. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2009/06/090610192431.htm
Oxford University Press. "Health Risks Of Nanotechnology: How Nanoparticles Can Cause Lung Damage, And How The Damage Can Be Blocked." ScienceDaily. www.sciencedaily.com/releases/2009/06/090610192431.htm (accessed September 23, 2014).

Share This



More Health & Medicine News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Costs Keep Mounting

Ebola Costs Keep Mounting

Reuters - Business Video Online (Sep. 23, 2014) The WHO has warned up to 20,000 people could be infected with Ebola over the next few weeks. As Sonia Legg reports, the implications for the West African countries suffering from the disease are huge. Video provided by Reuters
Powered by NewsLook.com
Liberia Pleads for Help to Fight Ebola

Liberia Pleads for Help to Fight Ebola

AP (Sep. 22, 2014) Liberia's finance minister is urging the international community to quickly follow through on pledges of cash to battle Ebola. Bodies are piling up in the capital Monrovia as the nation awaits more help. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Ebola Doctor Says Border Controls Critical

Ebola Doctor Says Border Controls Critical

AP (Sep. 22, 2014) A Florida doctor who helped fight the expanding Ebola outbreak in West Africa says the disease can be stopped, but only if nations quickly step up their response and make border control a priority. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins