Researchers at Mayo Clinic have developed a groundbreaking method to repair damaged heart tissue without open-heart surgery, potentially transforming treatment for heart failure patients.
The innovative approach uses laboratory-grown heart tissue derived from reprogrammed adult stem cells, delivered through a tiny chest incision rather than surgical opening of the thoracic cavity. In preclinical testing, the stem cell patches restored cardiac function and improved healing, representing a significant advance in regenerative cardiology.
Addressing an Unmet Medical Need
Heart attacks remain a leading cause of death worldwide. When blood flow to the heart is blocked, oxygen-deprived cells die and are replaced by scar tissue that cannot contract or conduct electrical signals, weakening the heart’s pumping ability.
“Once these cells are lost, the adult heart cannot regenerate itself,” explained Dr. Zhu, the principal investigator. “This explains why heart failure, particularly chronic heart failure resulting from functional myocardium loss, is often difficult to treat – the muscle simply cannot repair itself.”
Technology Innovation and Engineering Approach
The Mayo Clinic team collaborated with engineers from the University of Nebraska Medical Center to develop a flexible, paper-thin patch made from gelatin-coated nanofibers and microfibers. This hybrid scaffold supports a mixture of human cardiomyocytes, vascular cells, and fibroblasts to form living, beating heart tissue.
Before transplantation, the tissue is infused with bioactive factors including fibroblast growth factor 1 and CHIR99021 to promote new blood vessel growth and enhance cell survival after implantation. “The beauty of this design,” said Dr. Zhu, “is that it can be folded like a sheet of paper, loaded into a slender tube, and delivered precisely where needed through a small chest incision.”
Delivery System and Surgical Advantages
The minimally invasive delivery system represents a major improvement over previous approaches that required open-heart surgery – a procedure too risky for many patients already battling severe heart failure. Instead of sutures
the team uses a biocompatible surgical adhesive to secure the patch in place while minimizing additional trauma to surrounding tissue. Once positioned, the patch unfolds and naturally adheres to the heart’s surface, creating a stable platform for tissue integration and functional recovery.
Preclinical Results and Functional Outcomes
Testing in preclinical models demonstrated that the minimally invasive approach improved cardiac function compared to conventional methods, showing reduced scarring, enhanced blood vessel formation, and decreased inflammation. ”
Our results indicate that these engineered tissues not only survive but actually help the heart heal itself,” Dr. Zhu reported. “That’s the ultimate goal: to replace what’s lost and restore function.”
Research Context and Future Directions
The work aligns with Mayo Clinic’s Genesis Initiative, which aims to accelerate discoveries in human organ and tissue restoration and regeneration. While approximately 4,000 heart transplants are performed annually in the United States, thousands of patients die waiting for donor organs.
Dr. Zhu envisions that this technology could eventually provide an alternative option. The team plans to advance through larger preclinical studies to ensure therapy safety and effectiveness before progressing to human clinical trials, a process estimated to take approximately five years. “If we can make stem cell treatments accessible to more patients, especially those too fragile for open-heart surgery,” Dr. Zhu concluded, “we can save lives.”
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