A sealant has been created for wounds that cannot be clamped
Chemists from Boston University and Beth Israel Medical Center, USA, have created a gel that helps stop bleeding in wounds when it is impossible to apply a tourniquet or clamp the blood flow.
Often, death from injury is caused by bleeding that cannot be stopped in the usual way – by applying a tourniquet or a tight bandage (for example, bleeding from the aorta or intracavitary). Such wounds are more often received by a person in the conditions of military operations or being away from civilization, and it is critically important to stop the blood loss until the wounded person is taken to the hospital.
The ideal material for stopping blood loss should exclude pressure on damaged vessels, be suitable for stopping intracavitary hemorrhage, have mechanical flexibility to repeat the shape of the wound. In addition, it is necessary to be able to remove it without surgery.
American chemists have developed just such a material. This is a hydrogel based on a macromonomer (thioester) and a "crosslinking" substance based on polyethylene glycol (PEG). Thioester is an ester of thiol, a sulfurous analogue of alcohol. The "stapler" substance is PEG-maleimide. It is often used in reactions with thiols.
To prepare such a gel, it is necessary to mix aqueous solutions of the two components in a ratio of 1:1. At room temperature, they form a gel in one second.
The macromonomer is responsible for the composition and structure of the substance, and also creates active centers for gelation. Once bound to the "stapler" substance, it forms a network structure that does not flow, does not dissolve with other liquids and quickly closes the bleeding - the gel fills cavities in living tissue and mechanically blocks blood flow.
The hydrogel dissolves in a biocompatible solution. Thus, the wound can be closed before surgery, and then uncorked and operated on again.
The gel was tested on 27 rats – 12 with hepatic bleeding and 15 with aortic bleeding. In the first case, there were seven rats on which hydrogel was used and five in the control group. In the second – 10 rats, to which hydrogel was applied, and five control ones. As a result, in animals with hepatic bleeding, hydrogel reduced blood loss by 33%, and in animals with aortic wound – by 22% compared to control groups.
The created hydrogel significantly reduces blood loss and is compatible with other materials available to doctors, as well as meets the requirements for solubility, and it can be applied to bleeding that cannot be stopped by squeezing vessels. Previously existing substances did not have such a possibility.
The study was published in the journal Material Horizons (Konieczynska et al., A hydrogel sealant for the treatment of severe hepatic and aortic trauma with a dissolution feature for post-emergency care).
Recall that a similar substance was created by Russian scientists. True, it takes a little longer for it to set, but it does not need to be removed from the wound.
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11.01.2017