Scientists from ITMO University have found a way to effectively stop internal bleeding by magnetically-driven nanoparticles containing thrombin, an enzyme responsible for blood clotting.
A statement issued by the university says that a drug based on these nanoparticles can be injected intravenously and delivered straight to the site of a vascular injury, accelerating clot formation and reducing blood loss by 15 times.
It says the nanoparticles are not toxic to humans and can potentially be used for safe treatment. “Internal bleeding is a serious medical emergency. It may be caused by numerous medical conditions such as traumas or chronic diseases and it occurs in various body parts including the brain or the stomach. Yet the prognosis for majority of cases is quite pessimistic, as internal bleeding usually causes hematomas, organ dysfunction, and massive blood loss. For example, gastrointestinal bleeding was recently estimated to account for up to 20,000 deaths in the United States only,” the statement says.
It says that the drugs available in the market for stopping severe blood loss cannot work entirely on their own, and surgery is needed in most cases to fully stop internal bleeding. “In an attempt to stop bleeding more effectively, scientists are developing drugs that can be applied using a simple injection. The main issue with such drugs is that the remedy has to initiate clot formation only at the site of vessel damage instead of affecting the entire vascular system.”
The research conducted by the ITMO University scientists suggests that magnet-driven nanoparticles can be used to solve this problem more effectively. “The particles consist of two key components. The first is thrombin. It interacts with the protein called fibrinogen and triggers clot formation in order to block the damaged vessel. The thrombin is wrapped into a special porous matrix made of magnetite, the second main ingredient. This allows for precise control of the movement of particles inside the body using an external magnetic field.”
The statement notes that magnetic nanoparticles with thrombin have low activity, and they do not cause blood clotting if they are evenly distributed in blood vessels. Therefore, it is possible to inject a solution of particles intravenously and localize them where needed using a magnet. “When the patient receives an extra portion of fibrinogen, thrombin particles around the site of injury interact with it and the bleeding stops faster.”
Andrey Drozdov, a member of SCAMT Laboratory at ITMO University, is quoted in the statement as saying, “We tested the nanoparticles’ efficiency on human blood plasma samples and a special vessel model. After the first experiments with plasma, we found out that thrombin in our nanoparticles is less active compared to its free variant. Yet we went on with the tests and ran additional experiments on a model of the blood stream. We were able to observe how nanoparticles behave when the vessel is damaged. It turned out that magnetic localization compensates for lower activity. Nanoparticles reduce the clotting time by 6.5 times and can reduce total blood loss by 15 times.”
“Synthesizing these nanoparticles is not easy,” says Vladimir Vinogradov, the head of the laboratory. “It is important to keep their size down to 200 nanometers, otherwise they will not be suitable for injection. In addition, mild synthesis conditions are required so that the thrombin molecule does not break down and lose its activity completely. Finally, we could only use biocompatible components. We checked the toxicity of our particles with human cells and made sure they are completely safe even during prolonged exposure.”
The research is part of a project aimed at creating hybrid nanomaterial-based hemostatic drugs. Scientists are currently planning to test the drug based on the obtained material on animal models and, in case of success, run clinical trials. Researchers hope to create a nanoparticle-based hemostasis system that will be able to quickly and efficiently stop internal bleeding.