According to Dr. Sanjay Sinha at the University of Cambridge, it is almost impossible for an injured heart to fully mend itself. During a heart attack, arteries to the heart are blocked. Within minutes of being deprived of oxygen, the heart’s muscle cells start to die. 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 from 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.
Dr. Sanjay Sinha is working on exciting research at the University of Cambridge. Dr. Sinha’s team has pioneered the production of the different cell types needed for a heart patch. They are working on an innovative technique for growing heart patches in the laboratory – with the aim of using these to repair weakened cardiac tissue.
Their starting material is human embryonic stem cells, but they have also taken adult human cells and ‘reset’ their developmental clock. Dr. Sinha says “In theory, this means we can take a patient’s own cells and make patches that are identical to their own tissue. That said, millions of people are going to need this sort of therapy and so our focus at the moment is on coming up with a system where a small number of patches might be available ‘off the shelf’, with patients receiving the nearest match.”
The team is completing tests on the ideal combination of scaffold structure, peptide decoration and mix of cells to create a beating vascularised tissue. Next, the researchers will work with Dr. Thomas Krieg in the Department of Medicine to graft the tissue into a rat heart. Their aim is to show that the patch makes vascular connections, integrates mechanically and electrically with heart muscle, and contracts in synchrony with the rest of the heart. Once they’ve accomplished this, they will scale up the size of the patches for future use in people.
“It’s exciting,” says Sinha. “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. Our vision is that this technology will bring hope to the millions of patients worldwide who are suffering from heart failure, and allow them to lead a normal life again.”
Sanjay Sinha is a British Heart Foundation (BHF) Senior Research Fellow and a Reader in Cardiovascular Regenerative Medicine at the University of Cambridge. He completed medical training in Cambridge, followed by cardiology clinical training and a PhD in Manchester.