Article published on Medicoteknik in Danish, April 2025. Read the original article here.
Authors: Pablo Pennisi. Associate Professor, Bioengineer; Simone Riis Porsborg. Associate Professor, Cand. Scient. Med – Regenerative Medicine group, Department of Medicine and Health Technology, Aalborg University
Diseases in our tubular organs are a serious challenge to health. These include diseases such as cancer in the gastrointestinal tract, narrowing of blood vessels and scar tissue in the urinary tract. What these diseases have in common is that they disrupt the body’s normal transport of fluids, nutrients and waste products.
Traditionally, treatment has required tissue transplantation, but the great shortage of donors has increased morbidity and mortality for these patient groups. This is a major challenge for healthcare systems worldwide. 
To reduce the dependence on donors, the European Commission has identified bioprinting as a key technology that could eventually enable the production of functional tissues and organs for transplantation.
Bioprinting uses a special 3D printer that can create three-dimensional structures of tissues and organs. The printer uses a material called bioink, which typically consists of living cells mixed with gels that support the growth and function of the cells. There are different printers, including extrusion-based printers that place the bioink layer by layer to build complex biological structures.
Challenges of the urethra
A specific example is the disease urethral stricture, where the urethra narrows due to scar tissue or inflammation. This can lead to painful urination, frequent urinary tract infections and, in severe cases, kidney damage. Treatment is extremely difficult, as it often requires repeated surgical procedures with a high risk of relapse. Current surgical methods have several limitations. Sufficient tissue from the patient is often lacking, and complications can arise from taking tissue from other parts of the body. The urethra has a very fragile anatomy, surrounded by highly blood-supplied tissue, which makes it difficult to find suitable replacements.
This area is therefore particularly exciting within “regenerative medicine”, which focuses on repairing or replacing damaged tissues and organs. Advanced medicinal therapeutic products (AMTPs), which include cells and bioprinted tissues, are particularly interesting. Unfortunately, despite extensive basic research, there is still a significant gap between basic research and clinical application, which hinders the development and implementation of effective treatments. Therefore, there are only a few approved AMTPs on the market.
To close this gap, the European Commission has launched an initiative under the Horizon Europe programme in 2024 called “Bio-printing of living cells for regenerative medicine” within the “Tools, Technologies and Digital Solutions for Health and Care, including personalised medicine”.
Strong interdisciplinarity
STRONG-UR is one of six projects selected to participate in this EU effort on bioprinting of living cells for regenerative medicine. The project is led by researchers from Aalborg University and has an ambitious goal to advance the development of bioprinted regenerative solutions, in particular tissues for urethral reconstruction.
The project consortium is very broad, with researchers, clinicians, entrepreneurs, companies and interest groups covering the entire value chain.
Some partners contribute expertise in cell isolation, expansion, differentiation and regenerative medicine, which provides fundamental knowledge to the project. Others provide a solid foundation for the synthesis and characterisation of polymers for advanced hydrogels, while others have in-depth knowledge of urological diseases, in particular the anatomy and physiology of the urethra, as well as the design of clinical and preclinical studies.
Industrial partners contribute expertise in bioink formulation, bioprinting technologies, biomaterials for clinical applications, medical devices, GMP and intellectual property rights, which can ensure the further potential of the project. Finally, we have partners with strong documented experience in communication and dissemination, also in the urological field – with an eye for both clinicians and patients. Thus, the consortium brings together a wide range of expertise from different disciplines, which gives STRONG-UR a strong interdisciplinary dimension.
Bridging the gap
Our research project bridges the existing gap through collaboration between biomedical researchers, clinicians and companies. The focus is on the development of bioprinted urethral constructs that meet clinical and regulatory requirements.
By integrating innovative bioprinting technologies and conducting thorough preclinical testing, we aim to scale up production to Good Manufacturing Practices (GMP) standards and perform proof-of-concept studies in the preclinical phase.
In STRONG-UR, advanced bioprinting technology is used in combination with a specially developed bioink to create tailor-made tissues that mimic the structure of the natural urethra and have the same functional characteristics. The bioink is developed from smart biomaterials and hydrogels that can respond to specific stimuli. This allows the microenvironment of the cells in the bioprinted tissues to be controlled more precisely.
Among other things, the project seeks to make treatment faster and more cost-effective. This is “in situ” bioprinting, which means that the bioink is printed directly onto the damaged area of the urethra. This results in a bioprinted construct that fits the injury more precisely. In addition, freshly isolated stem cells are added to the bioink – without the need for the extensive cell expansion that traditional methods require.
The Engineer’s Role
Planning and implementing an interdisciplinary project like STRONG-UR requires a high degree of coordination between the various involved disciplines. At STRONG-UR, we believe that the collaboration between health engineers and specialists in Medicine with Industrial Specialisation (MedIS) has been key to effectively integrating knowledge and expertise from biomedical researchers, chemical and physical engineers, clinicians, industrial partners, and interest organisations.
With this combination, we are well-equipped to gather and promote collaboration between the project’s various fields. In this way, we have created a cohesive and targeted effort, where we truly strive to accelerate the development of advanced medical therapeutic products (AMTP).
We would like to challenge the reader, from students to hospital engineers, to actively participate in the mission to implement bioprinted tissues in the clinic as a routine treatment: By engaging in groundbreaking research and clinical trials, collaborating interdisciplinarily with experts from biology, engineering, and the medical field, and staying updated on regulatory requirements, you can significantly contribute to overcoming current challenges. Your engineering skills are invaluable in developing innovative solutions, and through education and building support in the medical professional community, you can help accelerate the adoption of bioprinted tissues in clinical practice. Your unique competencies and specialised knowledge make you central players in this exciting development.
The EU Commission has a strong interest in the development of new biomaterials for regenerative medicine, which supports our work and opens new perspectives for the application of 3D printing in this field. By utilising the latest technologies and collaborating across both professional and national borders, we can create groundbreaking solutions that not only improve patients’ quality of life and survival but also contribute to the development of the healthcare sector as a whole.
About the project
- The project name stands for: STrategies for Optimised bioprinting of Next Generation tissues for URethral regeneration and translation.
- The aim is to develop and test new strategies to engineer tissues that can improve the treatment of urethral diseases. This involves the use of advanced bioprinting technologies and biomaterials to create tailor-made tissue constructs that can be used in medical treatment.
- The project also includes the development of an in vitro model that will minimize the use of experimental animals. This model will mimic the biological conditions of the urethra and allow researchers to test new treatments in a controlled environment without involving animals.
- Partners in the project are Aalborg University (project coordinator), Aalborg University Hospital, Tampere University (Finland), Ghent University (Belgium), Università Cattolica del Sacro Cuore (Italy), University Medical Center Utrecht (Netherlands), European Association of Urology, 4Tissue (Belgium), Wellspect AB (Sweden), Brinter AM (Finland), AdBioInk Biosystem Technology (Turkey) and META Group (Belgium).
- STRONG-UR is supported by the EU’s Horizon Europe program. The project has a total budget of 7.8 million euros. The time horizon is from November 2024 to October 2028.
