Artificial heart valve: "The structure is meant to be broken down again by the body at a later point."

Interview with Dr. Svenja Hinderer, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB)

There are various artificial heart valves available for children, but they have one essential drawback: they need to be replaced because the children are still growing. The artificial valve, on the other hand, remains the same size – and subsequently becomes too small. This is why an artificial heart valve that grows over time would be ideal because it would prevent the children from needing repeated surgeries.


Photo:Svenja Hinderer

Dr. Svenja Hinderer; © Körber-Stiftung/David Ausserhofer spoke with chemist Dr. Svenja Hinderer at the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), who currently works on developing an artificial heart valve designed to grow with the body.

Dr. Hinderer, you are researching an artificial heart valve that is designed to grow with children’s bodies. Could you briefly describe what makes your developed approach so unique?

Svenja Hinderer: We studied the design of the extracellular matrix of natural heart valves to subsequently replicate its function. To do this, we use a variety of polymers such as polyethylene glycol and polylactic acid that- among other things- can be cross-linked with ultraviolet light. The materials are electrospun and can be populated with additional natural proteins. The latter can trigger different cellular responses. These varying layers make this process so interesting because we want to attract cells responsible for growth in the human body. The material has already been successfully tested for its function as a heart valve in a bioreactor where body temperature and blood pressure are simulated. The valve opens and closes under physiological pressures of 120 mmHg to 80 mmHg.
Photo: heart valve with support frame

Electric woven carrier substrate, fitted into a pig heart valve; & copy; Fraunhofer IGB

You currently also need human cells for your work. Why is that?

Hinderer: We need them to be able to conduct in vitro tests. We use the cells to check for instance whether the material is cytotoxic. Since the material is not meant to cause any negative effects later on in the human body, it needs to be biocompatible both before and after sterilization. Our vision is to later have a cell-free material. In fact, the material is intended to attract the desired cells in the body so they construct their own matrix. The actual polymer structure is meant to be broken down again by the body at a later point.

Have there already been successful animal experiments?

Hinderer: We are currently not that far along yet. That is why we also don’t know yet whether the material is actually going to grow inside the body. The potential is there due to the similarity to the native extracellular matrix but the actual growth in a child’s body still needs to be demonstrated. We still have several questions at this point that we first want to answer using the test tube. We would like to introduce an additional thin elastin membrane, for instance, to further improve the elasticity and durability of the heart valve. Not until then will we conduct animal research either using pigs or sheep to further test the heart valve material.
Photo: Simone Ernst; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Simone Ernst and translated by Elena O'Meara.