Removing kidney stones thoroughly and without residue

Kidney stones are a widespread disease. In order to be able to reliably remove even the smallest remnants of them, Purenum GmbH, a spin-off of Fraunhofer Institute for Manufacturing Technology and Advanved Materials IFAM, developed a gel that encloses small fragments and can then be removed without leaving any residue. This year, the product mediNiK was certified and is thus ready for the market.

In an interview with MEDICA-tradefair.com, Manfred Peschka talks about how the development of the gel came about, for which applications it is still conceivable and which hurdles the company had to overcome before mediNiK was ready for the market.

What is mediNIK and how does the hydrogel work?

Manfred Peschka: mediNIK is a hydrogel in which a two-component product is placed in the kidney one after the other: the first component encloses the kidney stone fragments, while the second component ensures that the first component forms a soft gel within a few seconds after its application. This process creates a composite that can be gripped with a conventional extractor tool to remove it from the kidney.

What made you develop a hydrogel that helps remove kidney stones?

Peschka: The idea came from urologists who wondered if there is an available adhesive for this type of application. My colleague Dr. Grunwald has published a book on natural and synthetic adhesives, which the urologists discovered during their research.

The product is now licensed and market-ready – what else has changed since our interview back in 2018?

Peschka: The product formulation has not changed but the regulatory hurdles for the use of a medical device are high. Creating a product that works is not enough – you must also set up a medical device quality management system to ensure consistent medical device quality. The products also need certification from a notified body. To obtain this authorization, you must document all production details, which is a very long and intricate process.

In other words, the quality management system was the critical factor for certification?

Peschka: Yes, that's basically correct. Another reason why things took a little longer in our case might be related to the changing EU framework requirements.

The MDD (Medical Device Directive) used to be the applicable framework, which first had to be implemented into national law. However, scandals that rocked the medical device world – think of the PIP breast implant scandal – have prompted the EU to tighten regulatory requirements of the Directive. Now we have adopted the MDR (Medical Device Regulation), which does not need to be implemented into national law and immediately applies in all EU countries.

We ended up being stuck in the changeover phase when the notified bodies had to restructure to ensure compliance with the new regulations. Unfortunately, as a small company without an additional product on the market, we were initially overlooked during this process.

Could the product also be relevant for other medical applications if it is modified?

Peschka: I am quite sure that's possible. For example, we tested whether the material works in the gallbladder as well. It does, but in the case of gallstones, the physician typically decides to remove the gallbladder. That means it does not benefit us to invest our time in this particular research area.

Does your company have other products in development?

Peschka: Yes, we do. Back when we developed the basic product outlines of mediNiK at the Fraunhofer Institute for Manufacturing Engineering and Materials Research as part of a research project, we tested many different formulations. One formulation ended up working too well for kidney stones, meaning it adhered too much. This inspired us to research an adhesive for bones.

The idea behind it is that fractures in the wrist or ankle joints can have tiny bone fragments that cannot be stabilized into place to grow back together correctly. Although this is not a big issue for the patient, it still prevents him or her from regaining full mobility once everything has joined back together. We could change that with an adhesive. Another benefit is that you would no longer need nails, plates, or screws to hold the broken pieces of bone together. This means you also would not need a second operation for their removal. But for now, we are still a long way away from that.

Circling back to the Fraunhofer Institute: What was the biggest challenge when you decided to spin off from the research setting and stepped into the field of medical adhesives?

Peschka: We had to overcome a few obstacles. It was actually quite easy to set up the company. We just had to find investors and funding and form the GmbH business model. Contract negotiation turned out to be more difficult: the Fraunhofer Institute was our employer and thus owns the patents. So, we had to negotiate the respective exclusive license agreements. As you can see, everything worked out well in the end.