Gel with platelets
Inflammation, ulcers, abnormalities of blood vessels, trauma and other conditions can lead to profuse internal bleeding. Patients who are forced to take anticoagulants for a long time are also at high risk of bleeding. Therefore, there is a need for both blood flow control and effective treatment of internal bleeding.
The ideal treatment is to quickly and effectively block the damaged blood vessel to stop the bleeding and allow the wall to heal, using a material that will gradually break down and eventually allow blood to flow through the restored vessel again.
Modern methods of treating internal bleeding include both solid and liquid materials. Emboli made of platinum or steel wire are usually used. They come in different lengths, shapes and thicknesses and are inserted into blood vessels using a special catheter. Liquid materials have also been developed that harden after being injected into a blood vessel.
But there are a number of difficulties in using existing methods. Since special catheters and special equipment are required for the insertion and installation of wire emboli, the procedure is complex and requires a highly qualified doctor. In addition, sometimes to ensure efficiency, it is necessary to block blood flow in several areas, in other cases, emboli are displaced or compacted, which requires repeated endovascular surgery. Liquid agents often leak during injections, leading to inaccurate placement, toxic effects on surrounding tissues and the need for a repeat procedure.
A joint team of clinical radiology specialists and bioengineering researchers from the Terasaki Institute of Biomedical Innovation, Los Angeles, set out to create an optimal material that will have the advantages of solid and liquid emboli, smoothing out their shortcomings, and also allow visualizing the healing process of the vessel.
In their previous study, the authors used an inexpensive hydrogel to stop internal bleeding. In addition to high biocompatibility and adjustable mechanical properties, the hydrogel has demonstrated the ability to deform during injection and then restore the shape to the desired configuration. This made it possible to deliver it using standard catheters without special equipment. When silicate nanoplates imitating platelet coagulation ability were added to the hydrogel, the resulting composite acquired high efficiency.
In a new study, the group improved this project by adding tantalum particles to the hydrogel for visualization. It has been proven that this metal is biocompatible, safe for medical use and excreted in the urine.
The researchers conducted various tests to determine the required amount of tantalum, as well as its effect on the mechanical properties of the hydrogel composite. They calculated the optimal ratio of the three components of the new composite gel. Experiments have shown that tantalum particles do not affect the mechanical properties of the hydrogel and retain their sterility over time.
Studies on live pigs treated with anticoagulant showed positive effects of a new composite hydrogel with tantalum, which created a dense embolus, blocking the damaged artery 40 times faster than using solid materials. The hydrogel embolus remained in place for four weeks and then naturally collapsed. Thanks to the tantalum component in the gel, interventions and monitoring in animal models were carried out with clear visualization in real time using computed tomography, fluoroscopy and ultrasound.
The reversibility of blocking the artery with a new hydrogel composite was demonstrated in additional experiments, during which the hardened embolus was easily removed using an aspiration catheter.
Tantalum hydrogel has many unique advantages over existing methods of stopping internal bleeding. It is a safe, easy-to-use and cost-effective method that demonstrates optimal efficiency, accuracy and versatility for a variety of medical conditions.
Article by H.Albadawi et al. Nanocomposite Hydrogel with Tantalum Microparticles for Rapid Endovascular Hemostasis is published in the journal Advanced Science.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on EurekAlert: Visible hydrogels for rapid hemorrhage control and monitoring.