Featured Research

from universities, journals, and other organizations

'Nano-anesthesia: New approach to local anesthesia?

Date:
April 11, 2014
Source:
Wolters Kluwer Health: Lippincott Williams & Wilkins
Summary:
A technique using anesthesia-containing nanoparticles —- drawn to the targeted area of the body by magnets —- could one day provide a useful alternative to nerve block for local anesthesia in patients, suggests an experimental study.

A technique using anesthesia-containing nanoparticles -- drawn to the targeted area of the body by magnets -- could one day provide a useful alternative to nerve block for local anesthesia in patients, suggests an experimental study in the April issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

"We have established proof of principle that it is possible to produce ankle block in the rat by intravenous injection of magnetic nanoparticles associated with ropivacaine and magnet application at the ankle," write Dr Venkat R.R. Mantha and colleagues of University of Pittsburgh School of Medicine. With further study, the nano-anesthesia technique might allow more potent doses of local anesthetics to be delivered safely during local anesthesia in humans.

Magnets Used to Attract Anesthesia-Containing Nanoparticles

The experimental pilot study evaluated the use of magnet-directed nanoparticles containing the local anesthetic drug ropivacaine (MNP/Ropiv) to produce anesthesia of the limbs. The researchers engineered nanoparticle complexes containing small amounts of ropivacaine and the iron oxide mineral magnetite. The MNP/Ropiv complexes were injected into the veins (intravenously, or IV) of anesthetized rats.

The researchers then placed magnets around the ankle of the right paw for 15, 30, or 60 minutes. The goal was to use the magnets to draw the nanoparticles to ankle. Once there, the particles would release the anesthetic, numbing the nerves around the ankle.

Sensation in the right paw was assessed by comparing the right paw to the left paw, which was not affected. Other groups of rats received standard nerve block, with ropivacaine injected directly into the ankle; or IV injection of ropivacaine alone, not incorporated into nanoparticles.

Injection of MNP/Ropiv complexes followed by magnet application produced significant nerve block in the right ankle, similar to a standard nerve block. The left ankle was unaffected.

Nano-Anesthesia Could Permit Safe Use of Higher Anesthetic Drug Doses

The ankle block produced by MNP/Ropiv injection was greatest when the magnet was applied for 30 minutes -- likely reflecting the time of maximum ropivacaine release. High ropivacaine concentrations were found in right ankles of the MNP/Ropiv group, suggesting "sequestration of the drug locally by the magnet."

In rats receiving MNP/Ropiv, the nanoparticles contained a total of 14 milligrams of ropivacaine -- a dose high enough to cause potentially fatal toxic effects. Yet none of the animals in the MNP/Ropiv group had apparent adverse effects of ropivacaine. This was similar to the findings in rats receiving 1 milligram of plain ropivacaine. Thus the safe dose of ropivacaine combined with nanoparticles could be at least 14 times higher, compared to IV ropivacaine alone.

Magnet-directed nanoparticles have previously been used for targeted delivery of chemotherapy drugs. The new study suggests that a similar technique could be used to attract local anesthetic-containing nanoparticles to specific areas, as an alternative to local anesthetic block -- like that used for foot and ankle surgery, for example.

Additional animal experiments would be needed before the MNP/Ropiv technique can be tested in humans. But if it proved safe, the magnet-directed approach could provide a useful new alternative for regional anesthesia -- delivering high concentrations of local anesthetics directly to the desired area, without increasing toxic effects.


Story Source:

The above story is based on materials provided by Wolters Kluwer Health: Lippincott Williams & Wilkins. Note: Materials may be edited for content and length.


Journal Reference:

  1. Venkat R. R. Mantha, Harsha K. Nair, Raman Venkataramanan, Yuan Yue Gao, Krzysztof Matyjaszewski, Hongchen Dong, Wenwen Li, Doug Landsittel, Elan Cohen, William R. Lariviere. Nanoanesthesia. Anesthesia & Analgesia, 2014; 1 DOI: 10.1213/ANE.0000000000000175

Cite This Page:

Wolters Kluwer Health: Lippincott Williams & Wilkins. "'Nano-anesthesia: New approach to local anesthesia?." ScienceDaily. ScienceDaily, 11 April 2014. <www.sciencedaily.com/releases/2014/04/140411153459.htm>.
Wolters Kluwer Health: Lippincott Williams & Wilkins. (2014, April 11). 'Nano-anesthesia: New approach to local anesthesia?. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/04/140411153459.htm
Wolters Kluwer Health: Lippincott Williams & Wilkins. "'Nano-anesthesia: New approach to local anesthesia?." ScienceDaily. www.sciencedaily.com/releases/2014/04/140411153459.htm (accessed July 28, 2014).

Share This




More Matter & Energy News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Shipping Crates Get New 'lease' On Life

Shipping Crates Get New 'lease' On Life

Reuters - Business Video Online (July 25, 2014) Shipping containers have been piling up as America imports more than it exports. Some university students in Washington D.C. are set to get a first-hand lesson in recycling. Their housing is being built using refashioned shipping containers. Lily Jamali reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
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