‘Heart attack’ patch repairs muscle scar tissue without stitches

Scientists have developed a stick-on patch that could one day be used to repair damage to the human heart.Scars left on hearts after cardiac arrests can lead to irregular heart rhythms. This is because scar tissue disrupt the electrical impulses that allow a heart to beat in time.

The new patch helps to ‘bridge’ the electrical impulses correctly across different parts of the heart.The flexible patch, which has been shown to work in animal models, is long lasting and has the significant advantage that it can be stuck onto the heart without the need for stitches.

The research, by an Australian and British team led by Dr. Damia Mawad at UNSW in Sydney and Professor Molly Stevens at Imperial College London, is published in the journal Science Advances.

Around the size of a postage stamp, the patch is fixed in place during surgery by shining a laser on it.It is made out of a sandwich of materials including chitosan, a material found in crab shells, a polymer, called polyaniline, and another chemical, phytic acid.

This acide ensures that the polymer keeps conducting electricity, even in the presence of wet body tisseus.The conducting layer in the patch is made out of a polymer called polyaniline, and also phytic acid, a chemical which reacts to switch the conducting layer ‘on’. The patch is made to adhere to the heart tissue by shining a green laser on it, in a patented technique developed at UNSW by Dr Antonio Lauto of Western Sydney University.

The patch was tested by implanting it in rats. It was found to improve the conduction of electrical impulses across the scar tissue.