The modern ageing society poses new challenges for medicine. For instance, the demand for medical practices which regenerate worn out tissue is increasing, amongst other things, for individuals to lead a healthy life at old age. Biomedicine in Bavaria is at the forefront of this research field.
Regenerative medicine is an innovative, but also complex biomedical area of expertise, in which great hopes have been placed. Stem cell research, gene therapy and tissue engineering, i.e. cultivation of tissue and cell complexes, promise good chances of recovery when fighting severe and incurable diseases such as cardiac, autoimmune and neurological diseases, paraplegia and Parkinson’s disease, chronic inflammatory diseases, diabetes, solid tumours, leukaemia, bone and cartilage diseases or defects and skin transplants. Regenerative medicine is already successfully applied in cases of leukaemia and joint cartilage defects.
At the “MedTech Pharma 2012 – Medizin Innovativ” congress of the MedTech Pharma e.V. forum in 2012, a separate range of topics with renowned speakers was dedicated to biomaterials. A large number of experts in this field of expertise were brought together in the Free State of Bavaria.
Regenerative medicine research working full steam ahead. Life expectancy keeps increasing and at the same time, more people are exercising regularly. This leads to an increased demand in methods of regenerating worn out tissue. Tissue engineering is a central technology of regenerative medicine and biomaterials are the material base. Cells for establishing new tissue structure require an appropriate architecture (scaffolds) for successful growth. A promising approach are the bioactive glass scaffolds developed by Prof. Dr. Aldo Boccaccini from the Erlangen-Nuremberg university. Biopolymers with non-organic nano fibre particles coat and infuse the scaffolds, thereby making them more resistant to fractures. Soluble products from glass influence osteogenesis and angiogenesis, i.e. the formation of bones and vessels. Nano structures improve cell adhesion and cell growth.
An example of how important organ functions can be restored using tissue engineering is the removal, cultivation and reinsertion of contractile myocardial tissue. With this method, Dr. Andreas Hilfiker from the Hannover Medical School (MHH) aims to prevent irreparable defects of this tissue due to loss of oxygen and nutrients supply in the cardiac tissue. The regeneration potential of the cardiac tissue cells is so low that the lost functionality cannot regenerate out of its own. As Prof. Dr. Jürgen Mollenhauer explained to the auditorium, this procedure has been working quite well for several years on autologous cartilage cell transplant of joint cartilage. Cartilage cells are taken from the patient, propagated in cell culture and implanted back into the damaged area, where they can rebuild cartilage tissue. However, problems have appeared recently from the regulatory side, as the effective therapy is now classified as being a regulatory pharmaceutical with all time high in time and cost consequences.
The BioTissue Technologies GmbH has developed two solutions for the therapy of cartilage defects: on the one hand, a cell-based product from patients’ own cells and a polymer-based absorbable carrier matrix. On the other hand, an implant from a cell-free and stable 3D carrier matrix. The bone marrow stimulating process is intensified by supporting the body’s own regeneration potential by attracting stem cells to the location of the cartilage defect.
A number of new therapeutic options, especially for cardiovascular diseases, are opend by highly bio-compatible, innovative silk fibres. A special spider imitated manufacturing process of silk enables the textile processing of the biomaterial, for example for small-diameter vascular prostheses. Robin Ross and colleagues from the RWTH Aachen is developing the optimal structure and coating so that artificial blood vessels become flexible and blood-tight.
The basis for regenerative medicine is especially adult stem cells and precursor cells from bone marrow and peripheral blood. However, cells with desired properties have to be separated from those with undesired effects. The cell separation method of Miltenyi Biotec GmbH is based on the connection of magnet particles on antibodies. Finally, the cells are analysed using specific reagents, as described by Volker Huppert.
Outstanding things can be achieved with patience and ingenuity. For example the successful creation of human tissue with cell-based 3D techniques and reconstruction of structures of defected organs and body parts. It was a long way to achieve this goal, which took almost two decades. Although it was and still is a brilliant idea, there are central factors and challenges to it such as vascularisation of vessels and carrier materials (scaffolds).
In order to grow replacement fibrosis from the body’s own cells, such as cardiac valves, different materials are colonised with human cells. Depending on the purpose, polymers, calcium phosphate, ceramics, gels or in special cases also bowel explants are used. The leading researchers in the field of regenerative medicine and biomaterials are Professor Dr. Heike Walles, chair Tissue Engineering and Regenerative Medicine at Würzburg university, and Professor Dr. Aldo Boccaccini, chair and head of the Institute of Biomaterials at Erlangen-Nuremberg university. As basis for transplants for trachea reconstruction, Heike Walles uses a very specific medium for a scaffold. Together with her work group and the Schillerhöhe clinic, she succeeded in developing a transplant with its own vascular system for clinical use. A severely injured patient with a burned oesophagus could be healed using this transplant.
As biomaterial for the reconstruction of body tissue, calcium phosphate ceramics provide a highly diverse range of applications. They are useful for both bone replacement material and tissue engineering. Since the scaffold material is very similar to natural bones in terms of its chemical composition, it has proven to be highly bio-compatible. The production of scaffolds is carried out by different rapid prototyping procedures, which were optimised by the work group of Ulrike Deisinger from the Friedrich-Baur research institute for biomaterials at Bayreuth University.
Ulrich Nöth, a physician and scientist at the Orthopedic Centre for Musculoskeletal Research (OZMF) at Würzburg University, and his work group Tissue Engineering are investigating tissue regeneration of cartilage and bones. Nöth prefers collagen-based gels as carrier material for cartilages. In the case of larger bone defects, much depends on how stable and how absorbable the carrier materials are. In various clinics research is also performed on regenerative treatment options for diabetes mellitus type 1, for example at the clinic for paediatric and adolescent medicine (Klinik für Kinder- und Jugendmedizin) in Munich. Although promising approaches have been developed, a matured therapy has not yet been implemented.
The methods of regenerative medicine offer great potential, which is also being recognised by more and more investors. Further funding is required to make these modern therapies available to more patients, especially due to the high approval expenses that are hardly affordable for many small and medium-sized businesses.
The author was born in Landshut in 1953 and studied human medicine at LMU in Munich. After having worked at the MHH Hannover, in the United States and Switzerland, Prof. Dr. Nerlich has been head of the Trauma Surgery department at Regensburg University Hospital since 1992. He is president of the International Society for Telemedicine and chairman of the Forum Medtech-Pharma e.V.