Magnetic nanoparticles can help stop internal bleeding faster and reduce blood loss in internal bleeding by a factor of 15. This may increase the survival rate of patients who suffer internal bleeding.
Internal bleeding can have serious consequences. Not only can bleeding lead to chronic disease, but also haematomas, organ failure or large-scale blood loss. In many cases, therefore, the prognosis for patients with internal bleeding is pessimistic. Several agents have long been available to stop severe bleeding, but none of them is capable of stopping internal bleeding without surgical intervention. The new drug can do this.
Nanoparticles with thrombin
Researchers at Russia's ITMO University have developed a new type of nanoparticle containing thrombin, an enzyme that plays an important role in blood clotting. The drug can be injected intravenously, allowing the drug to be delivered directly to the site of bleeding to stop internal bleeding.
The drug consists of two main components. The first is thrombin, an enzyme that plays a crucial role in blood clotting. Thrombin reacts with a protein called fibrinogen and causes blood to clot to repair a damaged blood vessel. Thrombin is wrapped in a porous matrix of magnetite, a mineral that reacts to a magnet. This allows the particles' position in the body to be accurately determined using an external magnetic field.
Guide to the right place with magnet
The researchers report that the magnetic nanoparticles have low activity and do not cause blood clotting if dispersed in blood vessels. This makes it possible to inject the drug into veins and then use a magnet to guide it to internal bleeding. By adding extra fibrogen, it is possible to speed up blood clotting and stop an internal haemorrhage faster.
"We tested the efficiency of the nanoparticles on human blood plasma and a special vein model," explained Andrey Drozdov, a member of the SCAMT Laboratory at ITMO University. "After the first experiments on plasma, we found that thrombin in our nanoparticles is less active than in a free variant. We then continued testing and performed additional experiments on a model of the circulatory system. This allowed us to observe how the nanoparticles behave if the blood vessel is damaged. It turns out that magnetic localisation compensates for the lower activity of the particles. Nanoparticles reduce the time needed for blood clotting by a factor of 6.5 and can reduce total blood loss by a factor of 15."
Safety
"Synthesising these nanoparticles is not easy," said Vladimir Vinogradov, head of the SCAMT Laboratory. "It is important to limit their dimensions to 200 nanometres, as otherwise they cannot be injected. In addition, synthesis under mild conditions is necessary to prevent the thrombin molecule from degrading and losing its activity completely. Finally, we could only use biocompatible components. We checked the toxicity of our particles with human cells and ensured that they are completely safe, even with long-term exposure."
ITMO University's research is part of a larger project aimed at developing nanomaterial-based hybrid coagulants. The researchers plan to test their nanoparticles in animal experiments in the near future. If these trials prove successful, the researchers want to conduct clinical trials. In time, the researchers hope to develop a nanoparticle-based coagulation system that can stop internal bleeding quickly and efficiently.
Burg forms between platelets
ITMO University, incidentally, is not the first party to want to stop internal bleeding using nanoparticles. Earlier, researchers from the University of Maryland, Baltimore County experimented with this. These researchers' nanoparticles form a bridge between different platelets and by doing so, in effect attach the platelets to each other, speeding up the blood clotting process. In this process, the nanoparticles are released into the bloodstream, after which they attach to a specific protein found exclusively on platelets activated during bleeding. Due to this property, the particles automatically 'stick' to the right place in the bloodstream.
Author: Wouter Hoeffnagel
Source: ITMO University
Source: University of Maryland, Baltimore County
Source photo: Pixabay / qimono
