Injectable tissue patch may help repair damaged organs

Aug. 14 (UPI) -- Researchers at the University of Toronto have developed a tiny patch of heart tissue with its own blood vessels that can be delivered via injection.

Invasive open-heart surgery is typically required to repair heart tissue destroyed by heart attack or other medical conditions by using regenerative cells or tissues.

A new study, published in today in Nature Materials, suggests that a technique using 3D slices of human tissue developed by biomedical engineering researchers at the University of Toronto can repair human heart tissue non-invasively.

The team was able to use a small needle to inject a repair patch without having to open the chest cavity to access the heart.

"If an implant requires open-heart surgery, it's not going to be widely available to patients," Professor Milica Radisic, of the University of Toronto Faculty of Applied Science & Engineering, said in a press release. "It's just too dangerous."

Researchers found a design that matched the mechanical properties of the heart tissue and had the necessary shape-memory by unfolding itself into a bandage-like shape after it emerges from the needle.

In tests on rats and pigs, researchers were able to grow real heart cells on the patch that was then injected into the animals.

"When we saw that the lab-grown cardiac tissue was functional and not affected by the injection process, that was very exciting," Miles Montgomery, a researcher in Radisic's laboratory, said. "Heart cells are extremely sensitive, so if we can do it with them, we can likely do it with other tissues as well."

The study showed that injecting the patch into rat hearts could improve cardiac function after a heart attack by allowing damaged ventricles to pump more blood than without the patch.

"You could customize this platform, adding growth factors or other drugs that would encourage tissue regeneration," says Radisic. "I think this is one of the coolest things we've done."