Stem Cell Patch Gently Heals Damaged Hearts Without Open-Heart Surgery

Heart failure often develops after a heart attack destroys oxygen-deprived cardiac muscle, leaving behind scar tissue that cannot beat or conduct electrical signals. Because the adult human heart has little regenerative capacity, patients with severe damage typically rely on mechanical pumps or transplants; however, many are too fragile for surgery or never receive a donor organ. Scientists have long explored stem-cell-based repair, but safe and effective delivery of engineered tissue has remained a major barrier. Now, researchers have designed a new minimally invasive approach using bioengineered heart tissue that can overcome these limitations.

Developed by Mayo Clinic (Rochester, MN, USA), in collaboration with the University of Nebraska Medical Center (Omaha, NE, USA), the method uses a paper-thin scaffold made of nano- and microfibers coated with gelatin. The patch is populated with human heart muscle cells, blood vessel cells, and fibroblasts derived from induced pluripotent stem cells. Before application, the engineered tissue is enriched with bioactive factors that promote vascular growth and improve cell survival. The design allows the patch to be folded, loaded into a slender tube, and delivered through a small incision, where it unfolds and naturally adheres to the heart’s surface without stitches, secured by a biocompatible surgical adhesive.

In a study published in Acta Biomaterialia, the researchers tested the stem-cell-based patch in preclinical models. Once delivered, the engineered tissue survived well, stimulated vascularization, and supported the damaged heart muscle. Compared with conventional surgical approaches, the minimally invasive method improved cardiac function, reduced scar tissue, and lowered inflammation. These results suggest that engineered cardiac tissue can repair injured regions while avoiding the risks of open-heart surgery, making the therapy potentially suitable for patients who are too frail for major operations.

This work also reflects broader goals in organ regeneration. The project aligns with Mayo Clinic’s Genesis Initiative, which aims to accelerate the development of technologies that restore or rebuild human tissues. Researchers envision a future in which patients could receive patches made from their own reprogrammed cells, reducing reliance on donor organs and shortening recovery times. Larger-scale preclinical testing is planned to further evaluate safety and readiness for translation to human trials.

"For patients with severe heart failure, there are very few options beyond mechanical pumps or transplants. We hope this approach will offer a new way to repair their own hearts," said Wuqiang Zhu, Ph.D., senior author of the study.

Related Links:
Mayo Clinic
University of Nebraska Medical Center