Featured Research

from universities, journals, and other organizations

Metal in heart non-hazardous to health, study shows

Date:
February 18, 2014
Source:
Friedrich Schiller University Jena
Summary:
Implants made of nickel-titanium alloy were evaluated in a long-term study. Results indicate that the release of nickel from wires made of nickel-titanium alloys is very low, even over long periods of time. Most of the metal released from implants in the heart are leaked in the first days and weeks, depending on the pre-treatment of the material. This is due, the researchers say, to the mechanical strain of the implant during the surgery. In the long run, however, the nickel release decreases to amounts of a few nanograms per day and is hence far below the amount of nickel that we absorb anyway through our food on a daily basis.

An occluder made of a nickel-titanium alloy. These medical implants are used for the correction of a defective cardiac septum.
Credit: Jan-Peter Kasper/FSU)

Materials Scientists at the University of Jena examine implants made of nickel-titanium alloy in a long-term study: The team led by Professor Rettenmayr and his colleague Dr. Andreas Undisz report in the current issue of the scientific journal 'Acta Biomaterialia' that the release of nickel from wires made of nickel-titanium alloys is very low, also over longer periods of time.

A trousers button, a coin or a watch can be dangerous for people with a nickel allergy. Approximately 1 in 10 Germans is allergic to the metal. "This raises the question of the safety of medical implants containing nickel," explains Professor Dr. Markus Rettenmayr of the Friedrich-Schiller-Universitδt Jena. Nickel-titanium alloys are increasingly used as material for cardiovascular implants in minimal invasive surgery. Once implanted, nickel-titanium alloys can release small amounts of nickel due to corrosion phenomena, the holder of the Chair of Metallic Materials explains. Our concern was that this could -- in particular over a long period of time -- lead to a nickel contamination in the patient's body that possibly results in health problems.

But these concerns are essentially unfounded: The team of Jena scientists led by Professor Rettenmayr and his colleague Dr. Andreas Undisz report in the current issue of the scientific journal 'Acta Biomaterialia' that the release of nickel from wires made of nickel-titanium alloys is very low, also over longer periods of time. The scientists could back up their statement in the first long-term study ever, which examined such nickel release in detail: The testing period for metal release, as requested for governmental approval of a medical implant, is only a few days. In contrast the Jena research team monitored the release of nickel over a time period of eight months.

Examination objects were fine wires from a superelastic nickel-titanium alloy that are, for example, applied in the form of occluders (these are medical implants used for the correction of a defective cardiac septum). Such occluders often consist of two tiny wire-mesh "umbrellas," approximately the size of a 1 Euro coin. The superelastic implant can be mechanically drawn into the shape of a thin thread, which then can be placed in a cardiac catheter. "By that means the occluders can be put into place via minimal invasive surgery," Dr. Undisz says. Ideally the implant will stay in the patient's body for years or decades.

Dr. Undisz and the doctoral candidate Katharina Freiberg wanted to find out what happens during this period of time with the nickel-titanium wire. They exposed samples of the wires, which underwent different mechanical and thermal pre-treatment, to highly purified water. They then examined the release of nickel according to pre-defined time intervals. "This wasn't trivial at all," Undisz says, "because the concentration of the released metal is often at the limit of detection." However, in co-operation with scientists from the Institute for Clinical Chemistry and Laboratory Medicine of the Jena University Hospital the materials scientists successfully developed a reliable test routine to measure the process of the nickel release.

"Mostly in the first days and weeks, depending on the pre-treatment of the material, considerable amounts of nickel may get released," Undisz summarizes the results. According to the materials scientist this is due to the mechanical strain of the implant during the surgery. "The deformation damages the thin layer of oxide covering the material. As a consequence the initial nickel release increases." In the long run, however, the nickel release decreases to amounts of a few nanograms per day and is hence far below the amount of nickel that we absorb anyway through our food on a daily basis.


Story Source:

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


Journal Reference:

  1. Katharina E. Freiberg, Sibylle Bremer-Streck, Michael Kiehntopf, Markus Rettenmayr, Andreas Undisz. Effect of thermomechanical pre-treatment on short- and long-term Ni release from biomedical NiTi. Acta Biomaterialia, 2014; DOI: 10.1016/j.actbio.2014.01.003

Cite This Page:

Friedrich Schiller University Jena. "Metal in heart non-hazardous to health, study shows." ScienceDaily. ScienceDaily, 18 February 2014. <www.sciencedaily.com/releases/2014/02/140218100622.htm>.
Friedrich Schiller University Jena. (2014, February 18). Metal in heart non-hazardous to health, study shows. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2014/02/140218100622.htm
Friedrich Schiller University Jena. "Metal in heart non-hazardous to health, study shows." ScienceDaily. www.sciencedaily.com/releases/2014/02/140218100622.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) — Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) — The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) — Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) — New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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:
from the past week

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