A heart patch that folds like paper and slips through a tiny incision is offering a glimpse of a different future for patients with failing hearts. Mayo Clinic researchers say their lab-grown tissue, delivered without opening the chest, restored function in preclinical tests and set the stage for a new class of minimally invasive regenerative therapies.
The work, published in Acta Biomaterialia, combines engineered heart muscle with a delivery method designed for patients too fragile to endure open-heart surgery. It is early, but the concept targets one of cardiologys most stubborn problems: how to replace heart muscle that the body cannot regrow on its own.
Why heart muscle rarely recovers
Heart attacks deprive muscle of oxygen, killing cells that are then replaced by scar tissue. Scar is sturdy but inert; it cannot contract or conduct electricity. Over time, that patchwork weakens the pump and triggers a cascade of enlargement and decline that can culminate in heart failure.
Once lost, adult heart muscle does not spontaneously return. For the sickest patients, care often narrows to mechanical pumps or a transplant precious options that are invasive, scarce, and not suitable for everyone. The goal of tissue engineering has been to offer a third path: build new muscle, integrate it with the old, and help the heart beat stronger again.
An origami-like patch, delivered through a tiny incision
The Mayo team, working with engineers at the University of Nebraska Medical Center, designed a flexible, paper-thin scaffold woven from nano- and microfibers and coated with gelatin. On this framework they grew a living blend of heart muscle cells, blood vessel cells, and fibroblasts the structural builders of tissue to create a patch that beats and metabolizes like native myocardium.
Before delivery, the tissue is infused with bioactive factors, including fibroblast growth factor 1 and CHIR99021, to encourage new blood vessel growth and improve the cells odds of survival after transplantation. Instead of sutures, the patch relies on a biocompatible surgical adhesive to anchor it to the hearts surface, minimizing additional trauma.
“The beauty of this design,” says Wuqiang Zhu, Ph.D., senior author of the study and a cardiovascular researcher at Mayo Clinic in Arizona, “is that it can be folded like a piece of paper, loaded into a slender tube, and delivered precisely where it’s needed through a small incision in the chest. Once in place, it unfolds and adheres naturally to the heart’s surface.”
What the early tests show
In preclinical testing, the minimally invasive approach improved heart function, reduced scarring, enhanced blood vessel growth, and lessened inflammation compared with conventional methods of delivering engineered tissue, according to the study and Mayo Clinics report of the findings. The researchers say the patch survived on the heart and supported healing, a pair of milestones that have proved difficult to achieve in past efforts.
“Our results show that these engineered tissues not only survive but actually help the heart heal itself,” Dr. Zhu says. “That’s the ultimate goal: to replace what’s lost and restore function.”
Importantly, the work remains preclinical. The experiments are an essential step toward human trials, but they are not yet evidence that the therapy works or is safe in people. The teams next phase involves larger-scale testing to probe durability, dosing, and potential complications before seeking regulatory clearance to enroll patients.
How it could change care if it works in people
By shifting from open-heart surgery to a small-incision delivery, the approach aims to bring regenerative therapy within reach for more patients. Individuals with advanced heart failure frequently carry a burden of other conditions that makes a sternotomy too risky. A patch that can be threaded into the chest and positioned precisely could lower that barrier.
The strategy also aligns with a broader regenerative vision: using a patients own reprogrammed cells to build personalized replacement tissue. Induced pluripotent stem cells, created by reprogramming ordinary adult cells, can be coaxed into cardiac lineages and layered into functional constructs. Paired with minimally invasive delivery, such tissue could one day patch the heart without the risks of donor rejection or the long recovery of major surgery.
“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,” Dr. Zhu says.
The need is considerable. Thousands of heart transplants are performed each year in the United States, while many more patients never receive one, constrained by donor supply and medical suitability. A successful tissue patch would not replace transplants or devices, but it could create a new rung on the treatment ladder earlier, less invasive, and potentially repeatable.
Questions science still has to answer
Even as the concept advances, key questions remain. Engineered tissue must not only survive but also coordinate with the hearts electrical rhythm, a challenge that has complicated previous cell-based therapies. Researchers will need to show that the patch integrates without triggering arrhythmias and that its benefits persist as the heart remodels over time.
Manufacturing and logistics also matter. Growing robust, standardized tissue at clinical scale, transporting it safely, and tailoring it to individual patients are nontrivial hurdles. So is demonstrating that the adhesive approach can anchor patches reliably across varied heart shapes and the constant motion of a beating chest.
The Mayo Clinic team acknowledges the road ahead. They estimate that moving from these results to first-in-human trials could take five years or more, a timeline that reflects the necessary safety evaluations and regulatory steps.
A carefully optimistic outlook
For now, the patch is a laboratory creation that performed well in animal testing, pointing to a possibility rather than a promise. But it is a possibility grounded in rigorous engineering and a delivery method tuned to the realities of heart failure care. If future studies confirm safety and clinical benefit, a patient could one day receive new heart muscle through a procedure measured in centimeters rather than inches.
“Our vision,” Dr. Zhu says, “is that patients could one day receive engineered heart tissue made from their own reprogrammed cells, delivered through a minimally invasive procedure no donor organ, no long recovery, just a repaired heart.”
Regeneration has long been medicines moonshot. This work suggests that, with careful steps, it might also be a path walked through a small incision, unfolding quietly into something stronger with each beat.