New gel could repair damaged heart after heart attack

18 March 2012

An injectable gel containing freeze-dried powdered heart cells could be an effective and safe treatment to repair heart tissue damage caused by heart attacks.

The gel was developed at the the Department of Bioengineering, University of California, San Diego and is planned to be tested in clinical trials by spin-out company Ventrix Inc.

The research has been published in the Feb. 21 issue of the Journal of the American College of Cardiology.

The hydrogel is made from cardiac connective tissue that is stripped of heart muscle cells through a cleansing process, freeze-dried and milled into powder form, and then liquefied into a fluid that can be easily injected into the heart.

Once it hits body temperature, the liquid turns into a semi-solid, porous gel that encourages cells to repopulate areas of damaged cardiac tissue and to preserve heart function, according to Professor Karen Christman of the UCSD Department of Bioengineering. The hydrogel forms a scaffold to repair the tissue and possibly provides biochemical signals that prevent further deterioration in the surrounding tissues.

“It helps to promote a positive remodelling-type response, not a pro-inflammatory one in the damaged heart,” said Prof Christman.

The research shows that the gel also can be injected through a catheter, a method that is minimally invasive and does not require surgery or general anaesthesia.

New, unpublished research suggests that the gel can improve heart function in pigs with cardiac damage, which brings this potential therapy one step closer to humans, said Christman.

There are few injectable cardiac therapies in development designed to be used in large animals such as pigs, which have a heart that is similar in size and anatomy to the human heart, Christman explained. “Most of the materials that people have looked at have been tested in rats or mice, and they are injectable via a needle and syringe. However, almost all of them are not compatible with catheter delivery and would gel too quickly, clogging the catheter during the procedure.

In experiments with rats, the gel was not rejected by the body and did not trigger arrhythmic heart beating, providing some assurance that the gel will be similarly safe for humans, the researchers note.