Chinese study finds way to better repair injured heart muscle

BEIJING -- Chinese scientists have made a breakthrough in a heart disease treatment that enables patients to rehabilitate from cardiac muscle tissue injuries.

Regenerative medicine experts at the Chinese Academy of Sciences (CAS) and doctors at the Nanjing Drum Tower Hospital in east China have developed an injectable collagen scaffold in stem cell therapy for patients with injured heart muscles.

Previous studies have proven that using stem cells, which have the potential to grow into a variety of heart cell types, could repair and regenerate damaged heart tissue. However, like any other therapy, injecting stem cells into the heart can fail or lead to poor cell survival.

"One difficulty was how to retain the stem cells at the injury site after cell transplant," said lead researcher Dai Jianwu, also a researcher at the Institute of Genetics and Developmental Biology under the CAS.

After years of experiments on animals such as pigs, Dai's team developed the collagen scaffold with biomaterials to solve the problem.

"It can be injected into the heart and prevent transplanted stem cells from moving around, maintaining their placement in the injured tissue, which will help increase the therapy efficiency," Dai noted.

A heart attack, or myocardial infarction, is permanent damage to the heart muscle caused by a lack of blood supply. Symptoms are tightness or pain in the chest, back, neck or arms. At least 2.5 million new cases and more than 1 million deaths from the disease are reported every year in China.

Common treatments include medications and surgery, but they have little effect, and many doctors view the disease as incurable.

Researchers started human trials in the Nanjing Drum Tower Hospital in March 2016 and continued until August 2019. According to Dai, 44 patients have received the collagen scaffold in their stem cell transplants, and follow-up studies were completed.

The results, published last week in the journal JAMA Network Open, show that the use of the collagen material can result in greatly reduced volumes of dead heart tissue in patients one year after cell transplants and can enable the heart to restore functions.

"For patients with severe illnesses, the effect is particularly obvious," said Dai, adding that the collagen scaffold is safe and feasible for application in larger groups of patients.

Dai has had previous successes in repairing organs with stem cells. In 2015, his team pioneered stem cell therapy for patients with chronic spinal cord injuries. Three years later, his team also cooperated with Nanjing Drum Tower Hospital, successfully using stem cells to rehabilitate a woman's damaged ovary, enabling her to give birth to a healthy boy.

The latest trials for heart attack patients have increased Dai's confidence in regenerative medicine, leading him to say that it is possible that all human organs could be regenerated in the future.