Catalan scientists from the Bellvitge Biomedical Research Institute (IDIBELL) have, for the first time, created a piece of heart tissue that can grow, mature, and survive long-term inside an animal. Until now, these types of experiments failed because these tissues are very complex, and if they don't receive enough blood and nutrients, they don't mature properly and eventually die. Now these researchers have achieved this goal using a 3D bioprinter: they have created small blood vessels with this tool, allowing the tissue to integrate perfectly into the circulatory system and survive for a month after implantation. Until now, the life expectancy of these tissues was no more than two weeks, so the researchers believe that using this technique, heart patches could be manufactured to replace affected parts of a patient's organ and help the patient regain its functionality.

Pacemakers help regulate the heart's rhythm when it's not beating properly, whether too fast, too slow, or irregularly. They are electronic devices that are sent running to keep the heart beating, and about 40,000 are installed in the state each year. There are several types, some of which don't even require wires or surgery to implant, and their size has been decreasing over the years. Now, researchers at Northwestern University in Evanston, United States, have developed a pioneering prototype in a study that is smaller than a grain of rice. It is a temporary device that, after its useful life, is absorbed by the patient's body, achieves effective stimulation in animals and human tissue, and could be implanted less invasively than current pacemakers, according to a study published in the journal Nature This Wednesday.