Researchers worked with biophysicists at Albert Einstein College of Medicine at Yeshiva University, to test nanoparticles — which contain nitric oxide gas to maintain blood circulation and the functioning of vital organs — in the bloodstream of hamsters.

Nitric oxide is naturally produced in the endothelial cells that line the inside of blood vessels and keep them open.

Whenever someone loses a large amount of blood, the flight-or-fight response to severe blood loss maintains circulation in the brain and heart, reducing the flow to the rest of the body.

As a result, nitric oxide is not produced and small blood vessels collapse throughout the rest of the body. The gas also cannot be injected or inhaled. It can be taken as a drug, but it is expensive and requires additional parts.

Massive blood loss can cause hemorrhagic shock — a potentially fatal condition that decreases blood flow and oxygenation in small blood vessels — that is typically treated with blood transfusions and other fluids containing proteins and starch to replace the blood volume. However, current treatment is limited to emergency rooms and trauma centers.

“The problem is, at the battlefield or when you have an earthquake or a natural disaster, there are no chances of spending time with victims of the hemorrhage,” bioengineering assistant professor Pedro Cabrales said. “[Doctors] have to do something fast and then move to the next patient. There is a logistic constraint that prevents them from treating everybody … What we try to do is to design a strategy that requires less active care.”

To address the problem, Yeshiva University researchers developed 10-nanometer-long particles (made up of a sugar structure and tiny bubbles of nitric oxide) that burst and slowly diffuse into the bloodstream when exposed to moisture. The particles are injected intravenously with saline solution and work for eight hours.

UCSD researchers tested the particles on hamsters by simulating 50-percent blood loss and treating it with two solutions. Compared to hamsters that only received a saline solution, the hamsters treated with the nanoparticles had a more stable heart rate and higher blood flow.

“The hamsters’ blood loss is severe enough to trigger all the response to hemorrhage,” Cabrales said. “It doesn’t kill the animal right away. [There’s] still 50- to 80-percent survival … What we wanted to have is a model that simulates what happens in a car accident or on the battlefield.”

From their research on the use of nitric oxide gas in nanoparticles, companies have found various uses. It can be used as a topical Viagra to increase blood flow, without the side effects of Viagra. It can also be used to treat bacterial infections in open wounds using a powder formula, or to treat malarial parasites and prevent hemoglobin toxicity.

Readers can contact Regina Ip at [email protected].