Three-dimensional matrix of allogeneic or xenogenic bone devitalized by hydrostatic high pressure for surgical applications
Method and corresponding device for the production of dimensionally stable allogenic or xenogenic bone replacement material.
In oral, maxillofacial and orthopaedic surgery, bone defects due to inflammation, tumours or traumas are commonplace. While in maxillofacial surgery the reconstruction of the bone is crucial for the subsequent implantation of dentures, in orthopaedics defects that exceed the maximum bridging size of 5-6 cm often have to be treated. While in maxillofacial surgery the reconstruction of the bone is crucial for the subsequent implantation of dental prostheses, in orthopaedics defects that exceed the maximum bridging size of 5-6 cm often have to be treated. Therefore, in addition to the knee and hip implants to be inserted, additional bone substitute materials (KEM) are used as fillers. These ensure easier integration of the implant.
The requirements for an ideal bone replacement material are high. On the one hand, they should activate the surrounding intact bone to form new bone matrix of its own, on the other hand, the KEM itself represents a carrier structure. In addition, biocompatibility, porosity and mechanical stability are crucial for successful bone reconstruction. Currently, the transplantation of autologous bone taken from the iliac crest is still considered the gold standard for the reconstruction of bone structures, as this bone material has the properties just mentioned. In order to reduce a possible immunological response of the recipient when using allogeneic or xenogenic material, a thorough devitalisation of tissue-specific cells and subsequent decellularisation is required. This is often achieved with strong chemical (SDS or Triton-X treatment), physical (ultrasound) or thermal processes. The disadvantage of these methods is that in addition to cellular components, matrix proteins such as collagen and inorganic structures such as calcium phosphate are damaged. These in turn ensure the mechanical stability that is necessary especially for larger defect bridges, since otherwise a regeneration is not possible with a transplant of such prepared KEMs.
With the invention presented here, decisive disadvantages of the previous processes can be circumvented. Thus, the innovation represents a gentle procedure for the devitalisation of tissues by means of hydrostatic high pressure, in which the extracellular matrix remains almost intact and thus retains its mechanical properties. At the same time, the containing cells pass into cell death and are therefore immunologically harmless for the recipients of the transplant. At the same time, the cells contained go into cell death and are thus immunologically harmless for the recipients of the transplant. n a first step, the donor bone, which can be either cancellous or cortical and not only allogenic but also xenogenic in origin, is converted into granular form. Subsequently, tissue-specific cells are thoroughly devitalised using the present invention by hydrostatic high pressure between 250 and 300 Mpa and a treatment time between 10 and 30 min. Afterwards, in the decellularisation phase, the granulate is freed from the killed partial components so that only inorganic structures and matrix proteins remain. In the next step, these are pressed into a desired shape under sterile conditions in a defined pressing process. The shape of the KEM according to the invention can vary from platelets to cylinders to cubes or blocks, as they are based on a manufactured hollow body that can be adapted according to specific requirements. A distinct advantage of using the pressed bone granulate according to the invention over native bone is the corresponding structure. Thus, the enlarged surface makes it possible to design the applications according to the invention, such as hydrostatic high-pressure treatment or decellularization by means of a rinsing chamber, more efficiently, since the cellular (residual) components are more easily accessible. At the same time, a mechanically stable framework is built up by the shaping pressing process, which also has a certain porosity due to the assembly of the granulate during the process. This makes it possible for recipient cells to colonise the bone matrix in the best possible way and to heal the bone defect filled with it.
» Production of a dimensionally stable allogeneic/xenogenous KEM by high-pressure treatment with subsequent rinsing and pressing process
Scope of application
Companies are being sought for commercial use as well as for development cooperations.
- DE pending
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