Svenja Hinderer wants to spare children with heart conditions from having to undergo numerous operations. The 32-year-old is developing a synthetic heart valve which encourages the body to rebuild a valve of its own.
TR: There’s already a range of different replacement heart valves. What’s different about this one?
SVENJA HINDERER: Biological implants, like those which use pig tissue, only last for around 15 years, while mechanical ones last around 25 years. That means lots of people have to undergo multiple operations throughout the course of their lifetime. Most importantly, there’s still no heart valve which grows alongside patients. As a result, children have to receive a replacement valve every two to three years until they’re fully grown. My goal is to create a heart valve which grows along with the recipient. Or more specifically, one which incites the body to build a natural valve of its own.
With a material which causes the body to reconstruct an extracellular matrix of its own. You can imagine this matrix like the frame of a house. Each kind of tissue has its own matrix, which in the human body is made up of stem cells. The intention is for these stem cells to come in and begin building a frame, while deconstructing the artificial material that we’ve introduced. In the end, you have a fully functioning, organic heart valve: That’s the dream.
I’ve developed a material from polymers whose fibre size and pores are very similar to the extracelluar matrix. I’ve covered the surface of these fibres with specific proteins which are recognised by the cells: so-called proteoglycans. The cells attach to these with their receptors and understand how they have to behave. The theory is that the cells will then feel at home. In other words, they will start rebuilding their matrix.
In vitro – in other words, in a test tube – I have demonstrated using human cells that the ‘correct’ cells are being drawn in, in this case stem cells from blood. They attach, grow and begin to construct a new, tissue-specific extracellular matrix which fulfils all mechanical requirements as well. There are pressures of between 120 to 80 millimetres of quicksilver column in the human heart, and under these conditions the valve holds back the blood, and opens and closes properly.
By Judith Reker
Translation: Teresa Woods