Tissue transplants of skin, tendons, vessels, and heart valves have become part of standard medical care in many countries. In the last ten years more than 40,000 transplants have been carried out in Germany alone, for example. Transplantation is often an emergency operation that saves lives. Heart valves are also used for the treatment of pediatric heart-valve defects. However, the annual demand for cardiovascular tissue is constantly increasing, and there is currently not enough human donor tissue available. Transplants made from animal tissue offer an alternative.
The treatment of these kinds of sensitive biological substrates for tissue prostheses poses a special challenge due to the high quality requirements, such as sterilization. To meet these requirements, the Fraunhofer FEP has developed a novel process for decellularization, UVA treatment, and sterilization of pericardial tissue (patent pending). A physical sterilization approach by means of accelerated low-energy electrons is used for this purpose.
This existing know-how can be applied to a wide range of applications in medical technology and especially to surface sterilization of delicate biological implant materials. Adaptation of the various technologies is always specific to the target material. Additional established methods, such as for evaluating changes in an extracellular matrix and their effects on biocompatibility, are available in the in-house biomedical lab.
- Decellularization of the tissue, thereby reduction of immunogenicity
- Subsequently, pre-crosslinking of the tissue by photo-initiated UVA treatment, renunciation of cytotoxic substances, such as e.g. glutaraldehyde
- Subsequent treatment with accelerated electrons for further cross-linking and final sterilization
- The challenge in the application for vascular and other tissue prostheses (e.g. skin, tendons) is the targeted adjustment of the penetration depth of the electrons for a cell-preserving sterilization, e.g. in order to preserve functional cells inside the vessel wall and at the same time to achieve an effective sterilization performance
- Treatment at the REAMODE test facility at substrate temperatures below 40°C
- Electron dose within the legally prescribed values (25kGy) with proven germ reduction
- Treatment of human pericardium as patch material in cardiac and vascular surgery is equally feasible with this procedure
- Minimal immunogenicity
- No use of cytotoxic substances such as glutaraldehyde
- Sterilization in a few milliseconds
- Final sterilization within packaging
- No radioactive sources
- Can be integrated into production processes
- Verified quality and tissue properties in cooperation with Herzzentrum Dresden GmbH at Dresden University of Technology