Bioinspired Hybrid Scaffolds for Bone Tissue Engineering

• Applicant: Professor Dr.-Ing. Chokri Cherif
• Subject Area: Biomaterials ; Orthopaedics, Traumatology, Reconstructive Surgery
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 519202302

Bone tissue consists of hierarchical structures of collagen fiber-reinforced hydroxyapatite (HAp), which are generated by cells (osteoblasts) and enable, among other things, high strengths with sufficient ductility, as well as regenerative capacity. Functional bone substitute materials must reflect this property profile and thus biomimetic pore sizes, mechanical properties and biocompatibility. Until now, technical solutions have required a compromise between biological and mechanical properties, since established methods and materials are not capable of reproducing both at the same time in a way that meets the requirements. The high proportion of cellular components makes an engineering abstraction and imitation of the bone structure very challenging, which is, however, necessary for an ideal bone substitute material. The project proposed here aims to fill this gap by exploring a biomimetic approach modeled on the glass sponge Euplectella aspergillum. This sponge is also hierarchically structured and exhibits construction principles that generate positive properties for bone substitution materials, such as high compressive strength, stiffness and ductility. At the same time, the chosen material approach is intended to develop the required biological properties. This requires the simulation-based development of Fiber Additive Manufacturing (FAM) for the production of hierarchically structured, highly porous and load-bearing scaffolds for bone replacement, which for the first time combine mechanical and regeneration-enhancing biological properties at the material and structural level. This should specifically overcome existing challenges in the therapy of bone defects and significantly increase the healing success of affected patients. The developed scaffolds will be extensively characterized mechanically and biologically in such a way that the basis for a MDR-compliant (medical device regulation) risk assessment will be laid. The target values are strongly dependent on the subsequent implantation region (e.g. jaw vs. femur). For the replication of the cortical bone, compressive strengths/bending stiffnesses of 100 - 200 MPa and elastic moduli of 5 - 20 GPa are to be achieved; for cancellous bone, porosities of 65 - 90 % are to be achieved, whereby the technology to be developed makes it possible to replicate both in one implant. Finally, the manufacturing technology will be industrially validated at INNOTERE, thus raising the developed technology from TRL4 to TRL6.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: INNOTERE GmbH
• Cooperation Partner: Dr. Jörg Opitz