Regenerating the Damaged Heart with Synthetic Cells

Cell therapies aim to transplant new cells into damaged tissue to improve its function. Unfortunately, most of these cells will die without being integrated into the target tissue, with most of the benefits coming from the factors they release before they die.

One solution to this problem is to produce a scaffold material that mimics the tissue, and thus supports the cells during transplantation. This approach has seen some success in in the lab in the form of the heart patch, a thin structure that can be placed on the surface of the injured heart to aid regeneration. These heart patches have important drawbacks, however, due to their use of live cells. They are expensive and time-consuming to make, are hard to store, and risk being rejected by the recipient’s immune system.

Now, research published in Science Translational Medicine has produced a heart patch that circumvents the drawbacks of live cells – by removing them from the patch entirely. Researchers started with a scaffold made from pig cardiac tissue with its cells removed. They then populated this scaffold with synthetic cells made from a biodegradable polymer. These ‘cells’ were made to contain all of the repair factors that real cardiac stromal cells would have secreted.

In rat models of heart attack, the patch was able to improve cardiac output by 50% compared to the control group, and also reduced scarring by 30%. Importantly, the patches did not lose any of their potency after being frozen, meaning that they can be stored for extended periods.

The patch can be frozen and safely stored for at least 30 days, and since there are no live cells involved, it will not trigger a patient’s immune system to reject it. It is a first step toward a truly off-the-shelf solution to cardiac patch therapy.

Ke Cheng, Randall B. Terry, Jr. Distinguished Professor in Regenerative Medicine at NC State’s College of Veterinary Medicine and professor in the NC State/UNC Joint Department of Biomedical Engineering