Nitric oxide in nanoparticles increases survival after massive blood loss

5 March 2011

Nitric oxide (NO) carried in the bloodstream by nano-size particles could prove a vital tool in maintaining blood circulation following massive blood loss.

The new therapy, developed at Albert Einstein College of Medicine of Yeshiva University, counters hemorrhagic shock by increasing the body's levels of NO gas, which, among other physiological functions, relaxes blood vessels and regulates blood pressure.

NO is so short-lived that delivering it in therapeutic amounts requires a method of sustained release, so the Einstein College team developed a method to encase the gas in microscopic-sized particles.  The therapy is created by adding the NO-containing nanoparticles to saline solution, which was then infused into the animals. Once in the body, the nanoparticles gradually release a sustained dose of NO to tissues.

In an advance that could improve battlefield and trauma care, scientists at Albert Einstein College of Medicine of Yeshiva University have used tiny particles called nanoparticles to improve survival after life-threatening blood loss.

NO-releasing nanoparticles (NO-nps) were infused into the bloodstream of hamsters, where they helped maintain blood circulation and protect vital organs. The research was reported in the February 22 online edition of the journal Resuscitation.

Coauthor Joel Friedman MD, PhD, professor of physiology & medicine and of medicine and the Young Men's Division Chair in Physiology at Einstein College said, "The new nanomedicine was developed to address the need for better field treatments for massive human blood loss, which can cause cardiovascular collapse, also known as hemorrhagic shock. This potentially fatal condition is best treated with infusions of refrigerated blood and other fluids. But such treatments are limited to emergency rooms or trauma centres.

"It is highly impractical to pack these supplies for use in rural emergencies, mass-casualty disasters or on the battlefield. Our nanoparticle therapy may offer the potential for saving lives in those situations. It's lightweight and compact and doesn't require refrigeration."

The nanomedicine was successfully tested in hamsters that had lost half their blood volume. "Animals given the nanoparticles exhibited better cardiac stability, stronger blood flow to tissues and other measures of hemorrhagic shock recovery compared to controls receiving saline solution minus the nanoparticles," reported Dr. Friedman.

Previously published studies by Dr. Friedman and colleagues have demonstrated the beneficial effects of NO-containing nanoparticles for healing antibiotic-resistant staph infections and abscess caused by those bacteria and for treating erectile dysfunction.

Reference

1. Parimala Nachuraju, Joel Friedman, Adam Friedman, Pedro Cabrales. Exogenous nitric oxide prevents cardiovascular collapse during hemorrhagic shock. Resuscitation, February 22, 2011 online edition.
Abstract available at: www.resuscitationjournal.com/article/S0300-
9572%2811%2900073-6/abstract