2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Cardiac muscle with 40x magnification
Doctors have successfully conducted the first phase of clinical studies of the VentriGel biomaterial, which improves heart function after myocardial infarction, according to the Journal of the American College of Cardiology: Basic to Translational Science. 15 patients who have had a heart attack over the past three years have successfully undergone drug injections. In addition, their health improved and they began to tolerate physical activity better.
In recent decades, doctors have been developing methods of treating myocardial infarction and coronary heart disease using regenerative medicine. Basically, scientists are testing the effects of different types of stem cells. Also investigated are drugs based on the extracellular matrix - a three-dimensional structure consisting of macromolecules, in particular, proteins and glycoproteins, which is necessary for the normal functioning of cells. True, so far the extracellular matrix is used mainly in reconstructive surgery for tissue restoration after injury or illness. There are no drugs for the treatment of cardiovascular diseases containing extracellular matrix on the market yet.
It should be noted that myocardial infarction leads not only to cell death. After it, inflammation develops, which leads to the destruction of the extracellular matrix, and a scar forms in the damaged tissue. In order to restore the natural extracellular matrix after myocardial infarction, researchers at Ventrix, a subsidiary of the University of California at San Diego, created VentriGel hydrogel based on cell-depleted extracellular matrix of porcine myocardium. As shown by in vitro studies of the biomaterial, it promoted the growth of endothelial cells that form blood vessels, and the differentiation of stem cells in rat myocardial tissue. In animals that have suffered myocardial infarction, the hydrogel has been shown to reduce the proliferation of connective tissue and improve heart function.
In 2014, the US Food and Drug Administration approved Phase I clinical trials of VentriGel to ensure the drug is safe for humans. For the tests, the creators of the drug selected 15 people 45–69 years old, 12 of them were men. All of them had suffered myocardial infarction in the period from two months to three years before the start of the study and they showed moderate dysfunction of the left ventricle. Doctors injected participants with up to 18 VentriGel injections and then monitored them for a year. Before the injection, as well as three and six months after them, the subjects underwent an MRI of the heart to assess the condition of the heart tissue, and checked how far they would travel during the test time. Participants also filled out a questionnaire that assessed the quality of life, and doctors examined them and assigned them a level of heart failure according to the gradation of the New York Heart Association.
All patients underwent injections of the drug and none of them interrupted the experimental treatment. The physical condition of the subjects improved, they began to better endure loads and walked a greater distance in the same time, on average 35.6 meters further (p = 0.03) after three months, and 44.4 meters further (p = 0.007), after six months … Also, according to the questionnaire, the patients' quality of life improved within a month (p = 0.045). It continued to rise after three months and six months, but already insignificantly. In addition, the subjects had improved symptoms of heart failure (p = 0.04), which allowed doctors to assign the volunteers a higher grade according to the New York Heart Association - that is, patients became better.
Ventrix is now preparing for a second phase of clinical trials, which will be conducted on a randomized sample with a larger number of participants. The goal of the second phase is to find out how effectively the hydrogel improves heart function in people with heart failure.
Previously, researchers found a way to patch the heart with slug mucus - they created a biological adhesive based on it. The authors tested the effect of the material on pork skin, heart, arteries and liver, and made sure that it is firmly attached to tissues and withstands a humid environment and mechanical stretching.
