This is why you feel sore. Then, during rest, and most importantly, sleep, your muscles patch up the damages, making them ...

Sewn on to the heart, the 3cm (1in) by 2cm patch, grown in a lab from a sample of the patient's own cells, then turns itself into healthy working muscle. It also releases chemicals that repair and ...

The patch is designed to help cardiac muscle beat more strongly after a heart attack. This photo shows a sample patch next to a model of the human heart. Disclaimer: AAAS and EurekAlert!