Natalia, what are you working on at the institute?

In the “Biofunctional Materials and Point-of-Care Diagnostics” working group, we develop materials and surfaces for medical applications. These include stents, artificial heart valves, and bioactive structures that support the regeneration of bone and tissue.

What exactly is point-of-care diagnostics? Do you have an example of how it is used?

Point-of-care diagnostics (POCT) refers to immediate testing performed directly on the patient – even outside of a clinical setting. A well-known example is the COVID-19 self-test.

Blood tests provide valuable insights into the causes and progression of a disease. This is where point-of-care diagnostics come in: they quickly determine the current state of health and support physicians in diagnosis and treatment.

To analyze many components in the blood, it is necessary to separate plasma or serum from other blood components. This separation is usually performed in centrifuges or using special blood separation membranes. In collaboration with academic and industrial partners from South Korea in the PlasmaSep project, we have developed a portable device that separates serum from a small volume of whole blood (< 5 ml). To do this, a vial containing a previously collected whole blood sample is inserted into the device. An activated element produces a vial of isolated serum at the outlet – completely free of chemicals. The serum can now be analyzed in the POCT analyzer.

Another area of your research is biofunctional materials. Where do you see potential applications here?

Cardiovascular diseases and complications resulting from their treatment are among the leading causes of death worldwide. Aortic valve defects contribute significantly to this. Depending on the severity, patients may require repair or replacement of the heart valve. The implants used for this purpose can be divided into two groups: mechanical and biological heart valves.

Mechanical heart valves are made of artificial materials. Their main advantage is their long lifespan of 20 to 30 years. However, these implants increase the risk of thrombosis, meaning that patients must take blood-thinning medication for the rest of their lives.

Biological heart valves generally do not cause this problem and are therefore a promising alternative. They are often made from non-human (xenogeneic) materials such as pig or bovine tissue. However, due to progressive calcification of the tissue, bioprostheses can fail after 10 to 12 years.

When soft tissue calcifies, the implant becomes stiffer. This can lead to blood flowing backward (regurgitation), the valve narrowing (stenosis), or the tissue even tearing. To prevent this, xenogeneic tissue is often pretreated. The goal is a final product that is biocompatible, non-toxic, and durable, retains its mechanical properties, and does not trigger thrombosis or immunological reactions.

In the VENUS project, we are developing a pretreatment against calcification for elastin-rich xenogeneic materials. We are using fetuin A – a natural compound that can inhibit calcification. We are developing various strategies to immobilize fetuin A on elastin-rich tissue samples and grafts derived from the bovine jugular vein and are investigating these in vitro and in vivo (i.e., in the laboratory and in living organisms).

The focus of heart valve material development is on biocompatibility, biostability, and the calcification properties of the tissues. For characterization, we use, for example, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, optical coherence tomography (OCT), or scanning electron microscopy (SEM).

The VENUS project (funded by the Saxon State Ministry of Science, Culture, and Tourism SMWK, grant number 100631657) involves partners from Turkey, Poland, and Latvia; through collaborations in Brazil, we can also apply the technology in practice in the future.

You and your team travel a lot around the world.

That’s right. In addition to the projects mentioned, we have other collaborations, for example in Indonesia and Australia. And just as our projects are international, so is our team. My group includes staff and students from 13 countries. These diverse cultural backgrounds bring a variety of perspectives to the table. This noticeably enriches our collaboration. I am proud to lead such a dedicated research group here at Fraunhofer IKTS.