Repairing heart cells with hydrogel

Every year, an estimated 785,000 heart attacks occur in the United States. However, there is no known treatment for the damage that follows a heart attack, including the development of scar tissue in the heart, which hinders muscle function and can lead to heart failure.

This month, a company spun out of The University of California, San Diego named Ventrix has conducted a first-in-human FDA-approved Phase 1 study to prove the safety of an injectable hydrogel to repair damaged heart tissue. It aims to restore cardiac muscle function in patients who have experienced a heart attack.

Ventrix’s hydrogel is the first of its kind to be tested in treating damaged cardiac tissue. It is composed of the natural scaffolding of cardiac muscle tissue, also known as extracellular matrix (ECM). ECM hydrogel products have shown to be useful in treating poor blood circulation due to artery disease in other preclinical studies, but never before for heart conditions. Ventrix’s VentriGel can be injected via catheter into patients 2 to 36 months after they have suffered a heart attack.

Researchers from Ventrix published the results of their study in the Journal of the American College of Cardiology: Basic to Translational Science. Karen Christman, professor of bioengineering in the Jacobs School of Engineering and the Institute of Engineering in Medicine at UC San Diego, said in a press release, “Although the study was designed to evaluate safety and feasibility and not designed to show whether VentriGel effectively helps improve heart function, we observed some improvements in patients.” Christman, who is also the paper’s senior author, continued, “For example, patients could walk longer distances. We also observed signs of improving heart function in patients who experienced a heart attack more than one year prior to treatment.”

Upon injection, VentriGel attaches to cardiac tissue and constructs a scaffold for repairs, allowing healthy cells to move into the region and overwhelm scar tissue, thus improving cardiac function. The ECM scaffold originates from pigs, but heart muscle cells from the animal are completely removed before the connective tissue is freeze-dried and processed into a powder. The liquified powder can be injected without surgery and turns into a porous gel upon contact tissue at body temperature.

The FDA-approved study, successfully conducted by Ventrix, monitored the hydrogel’s effects on 15 patients who each received up to 18 injections via catheter into a particular region of the left ventricle chamber of the heart over the course of six months. All of the participants were suffering from some form of heart failure after a recent heart attack, and half had experienced a heart attack in the previous year.

A six-minute walking test and health questionnaire were administered at three-month intervals through the study in addition to MRI scans on the same schedule. VentriGel had minimal side effects and did mitigate symptoms for many participants. However, in order to fully explore the effectiveness of the treatment, Ventrix is preparing to conduct a Phase 2 clinical trial on a much larger scale. If it pans out, VentriGel may make the dangerous aftereffects of heart attacks a thing of the past.