Scientists say hearts may someday be repaired using biomaterials and miniscule fibers smaller than a human hair.
Heart attack followed by heart failure is a leading cause of death, particularly in the West. According to experts, nearly a million Americans suffer a heart attack, or mycardial infarction (MI), each year, and a half million more experience more than one heart attack.
Damage to the heart muscle following an MI can lead to cardiac failure in which a weakened heart can no longer keep up with the demands of the body. Those with cardiac failure often die within a few years of diagnosis.
But hearts can be healed.
At her lab at the University of California San Diego, biomedical engineer Karen Christman is conducting experiments in pigs to regenerate the heart using healthy engineered myocardial tissue. All of the cells in the tissue are stripped away, creating a ghost-like, white scaffolding, which is processed into a liquid. The material is then injected into damaged portions of the pig's heart muscle following a heart attack.
Once inside the heart, Christman says the liquid forms a fibrous and porous matrix. “It then induces the body’s own cells to come into that and help to prevent this negative remodeling process that happens after a heart attack and therefore prevent heart failure," she said.
Meanwhile, scientists at National Cheng Kung University in Taiwan and the University of California in San Francisco California report creating polymer nano-fibers made of peptides to help heal the heart. Peptides are molecules formed from two or more amino acids or proteins. In their experiments, the researchers added a vascular or heart growth molecule to the mix and injected the combination into rodents’ hearts immediately following a heart attack.
One month later, the rats’ heart function had improved.
Inside the damaged tissues, the nano-fibers had formed a scaffolding to support the growth of new arteries and attract cells to repair damage to the heart. The investigators also conducted the experiment with pigs, whose hearts more closely resemble that of a human heart, finding that the nano-fiber and heart growth combination started to repair and restore normal function to those animals' hearts, as well.
Christman praises the nano-fiber research. “I think it’s quite an exciting study. And I think we will start to see the potential new injectable biomaterial therapies translated into people in the near future," she said.
Christman and her colleagues have formed a biomedical company to develop her lab's therapy for human trials. They hope to begin early clinical studies next year
An article on the use of nano-fibers to repair heart damage and a commentary by Karen Christman are published in the journal Science Translational Medicine.