RWTH: Replace cartilage with bio-ink
10 million euro funding from the Werner Siemens Foundation for a new type of tissue replacement. Project by DWI and RWTH Aachen.
Growth and replacement of damaged cartilage tissue using a groundbreaking 4D printing technology: This is what an interdisciplinary team from the DWI – Leibniz Institute for Interactive Materials and the RWTH Aachen is striving for. It will receive funding of around 10 million euros from the Werner Siemens Foundation for five years to develop a so-called bio-ink with special properties in the “TriggerINK” project.
The human body consists of an abundance of differently structured and sometimes very complex tissue. If they are damaged, medicine is faced with major challenges in restoring their function. Although there are procedures to be able to carry out repairs to the cartilage in the knee, for example, such procedures do not lead to a long-term cure that restores the damaged tissue and its full functions. Accordingly, several operations are often necessary, since one treatment does not lead to stable, healthy and functional cartilage.
Alternative technology for tissue replacement
In the TriggerINK project, the DWI-RWTH team wants to develop an alternative technology for tissue replacement. It is led by Laura De Laporte, Professor of Advanced Materials and Biomedicine. Professors Stefan Hecht (3D printing by light), Andreas Herrmann (active substance release by ultrasound) and Matthias Wessling (chemical engineering) complete the team. TriggerINK uses the innovative principle of 4D printing, for which a special bio-ink is designed. 4D printing is a further development of 3D printing technology: In conventional 3D printing, a material is applied layer by layer, creating a three-dimensional structure – like a cube. “The additional factor that also gives 4D printing its name is ‘time’: We build special components into the ink that react to external stimuli at very specific times. The printed material – in the example the cubes – can be moved with light or bioactive components can be released with ultrasound if necessary,” explains De Laporte.
The team now wants to develop a new method for replacing damaged body tissue: by printing 4D structures directly into the affected wound. To test the technology, the researchers selected cartilage in the knee joint. “We face a variety of challenges when trying to regrow healthy tissue at damaged sites. For example, the printed material must have a very specific structure that is comparable to its natural counterpart. It therefore contains pores and oriented microstructures that promote the growth of the body’s own cells into the tissue so that it can once again fulfill its original function. In the case of the knee joint, for example, it has to withstand pressure or friction,” explains Professor Matthias Wessling.
The idea of TriggerINK includes fluently merging steps during the printing process. The various properties of the bio-ink come to light: “The aim is to continuously print the bio-ink into the wound. It contains various ingredients that react, for example, to exposure to light. This creates crosslinks during the printing process that form a support structure and pores,” explains Hecht, in whose laboratories such special light-sensitive building blocks are developed. “We are striving to develop a medical product – that means that the perspective of the user from the clinic is also indispensable for us. That is why we are also supported and advised by high-ranking colleagues from medicine and molecular cell biology,” says Professor Stefan Hecht.
For the ink, the team will use a technology that Laura De Laporte developed and patented: the so-called ANISOGEL for directed growth of nerve cells. Furthermore, the organic ink should contain encapsulated growth factors and immune-modulating active ingredients. “These can be released with the help of ultrasound if necessary and should thus support the healing process,” explains Professor Andreas Herrmann. He specializes in alternative drug delivery systems.