Scientists Create Living ‘Patch’ to Heal Infant Hearts
A BETTER FIX–Jeffrey Jacot, Ph.D., foreground, and Seokwon Pok, Ph.D. of Rice University and Texas Children’s Hospital, have created a “living” patch to repair heart defects in infants. The patch is designed to biodegrade over time and leave behind only healthy tissue. (Photo by Jeff Fitlow)
A painstaking effort to create a patch made of living material to heal infant hearts is paying off at Rice University and Texas Children’s Hospital.
The proof is in a petri dish in Jeffrey Jacot’s lab, where a small slab of gelatinous material beats with the rhythm of a living heart.
Jacot, Ph.D., and his tissue-engineering colleagues have produced a material called a bioscaffold that could be sutured into the hearts of infants suffering from congenital heart defects. The scaffold, seeded with living cardiac cells, is designed to support the growth of healthy new tissue. Over time, it is designed to degrade and leave a repaired heart.
Details of this research were published recently in the journal Acta Biomaterialia. The lead author is Seokwon Pok, Ph.D., a postdoctoral researcher at Rice.
Patches used now to repair congenital heart defects are made of synthetic fabrics or are taken from cows or from the patient’s own body. About one in 125 babies born in the United States is born with a heart defect.
One such defect is a condition known as Tetralogy of Fallot, in which a hole exists between the right and left ventricles of the heart, resulting in “blue baby syndrome” due to lack of oxgen in the blood. To repair the condition, a patch is used to close the hole between the heart ventricles.
Current strategies work well until the currently available patches, which do not grow with the patient, need to be replaced, said Jacot, an assistant professor of bioengineering at Rice and director of the Pediatric Cardiac Bioengineering Laboratory at Texas Children’s Hospital.
“None of those patches are alive,” Jacot said, including the biologically derived patches that are “more like a plastic” and are not incorporated into the heart tissue.
“They’re in a muscular area in the heart that’s important for contraction and, more so, for electrical conduction,” he said.
Electrical signals have to go around this area of dead tissue, Jacot said. And having dead tissue means the heart produces less force, “so it’s not surprising that children with these types of repairs are more at risk for developing heart failure, arrhythmias and fibrillation,” he said.
Jacot hopes the “living” patch he and fellow researchers are developing will eventually replace current patches. Surgeons would perform the same operation they’ve always performed – just with a better patch.
Years of testing await the researchers before human trials can begin, but Jacot and his team are already looking ahead to the possibilities their success could offer. They hope to find a way to mix stem cell-derived heart cells from a patient into the patch material at the beginning of the process. Stem cells may be derived from several possible sources, including amniotic fluid routinely drawn from the newborn’s mother, the subject of an ongoing study in Jacot’s lab. The cells would make a patch genetically identical to the child, and the patch could be implanted shortly after birth.
“If we can make a patch that works immediately,” Jacot said, “one that contracts and conducts and has living cells and grows with the patient, what other surgeries could we do in the future that nobody can do now?”