Patching up a broken heart
It is almost impossible for an injured heart to fully mend itself. Within minutes of being deprived of oxygen – as happens during a heart attack when arteries to the heart are blocked – the heart’s muscle cells start to die. Sanjay Sinha wants to mend these hearts so that they work again.
We are recreating a tissue that has all the components we see in an organ, where the cells start talking together in mysterious and wonderful ways, and they start to work together as they do in the body.
- Sanjay Sinha
When the body’s repair system kicks in, in an attempt to remove the dead heart cells, a thick layer of scar tissue begins to form. While this damage limitation process is vital to keep the heart pumping and the blood moving, the patient’s problems have really only just begun.
Cardiac scar tissue is different to the rest of the heart. It doesn’t contract or pump because it doesn’t contain any new heart muscle cells. Those that are lost at the time of the heart attack never come back. This loss of function weakens the heart and, depending on the size of the damaged area, affects both the patient’s quality of life and lifespan.
“In many patients, not only is their heart left much weaker than normal but they are unable to increase the amount of blood pumped around the body when needed during exercise,” explains Dr Sanjay Sinha. “I’ve just walked up a flight of stairs… it’s something I take for granted but many patients who’ve survived heart attacks struggle to do even basic things, like getting dressed. While there are treatments that improve the symptoms of heart failure, and some even improve survival to a limited extent, none of them tackles the underlying cause – the loss of up to a billion heart cells.”
The numbers are stark. “Half a million people have heart failure in the UK. Almost half of them will not be alive in five years because of the damage to their heart. At present, the only way to really improve their heart function is to give them a heart transplant. There are only 200 heart transplants a year in the UK – it’s a drop in the ocean when many thousands need them.”
Sinha wants to mend these hearts so that they work again. “Not just by a few percent improvement but by a hundred percent.”
He leads a team of stem cell biologists in the Cambridge Stem Cell Institute. Over the past five years, with funding from the British Heart Foundation, they have been working with materials scientists Professors Ruth Cameron and Serena Best and biochemist Professor Richard Farndale on an innovative technique for growing heart patches in the laboratory – with the aim of using these to repair weakened cardiac tissue.
Image credit: The District and Jonathan Settle
Reproduced courtesy of the University of Cambridge
The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Sir Leszek Borysiewicz is also the President of the Cambridge Network.