In situ printing of resorbable, osteoinductive hybrid materials: Exploration of a novel therapeutic concept for segmental jaw bone defects based on the example of cleft alveolar osteoplasty

• Applicant: Professorin Dr. Paula Korn
• Subject Area: Dentistry, Oral Surgery
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566842371

The clinical gold standard for cleft alveolar osteoplasty and augmentation of segmental jaw bone defects is still the use of autologous bone grafts, despite the donor site morbidity and additional surgical site The development of an equivalent artificial bone graft is therefore of high clinical relevance. The combination of calcium phosphate-based biomaterials with the regenerative potential of stem/osteogenic progenitor cells in the sense of tissue engineering (TE) has already led to promising initial results. However, the classic TE approach – the transplantation of materials pre-colonized with cells in vitro – is very difficult to bring into clinical application due to the high effort as well as existing regulatory hurdles. Other challenges include ensuring adequate degradation of the biomaterials and good anchoring in the defect with close contact to the supporting bone. All these aspects are addressed in the project. The aim is to develop a flexible material system that combines different components with different properties: (1) a calcium phosphate cement (CPC), which is resorbable by osteoclasts as well as osteoconductive and provides mechanical stability to the graft, (2) mesoporous bioactive glass (MBG), which can accelerate degradation in composites with CPC and serve as long-lasting drug delivery system, and (3) hydrogels as rapidly degrading drug delivery systems with high loading capacity. This material system should be applicable by means of coaxial extrusion, leading to a hybrid material with a hydrogel in the core of the extruded strand that is surrounded by a CPC-MBG composite. Our hypothesis is that the combination with a hydrogel further accelerates the degradation of the CPC-MBG scaffold and thus, favors the defect ossification, which is particularly relevant in cleft palate defects in the growing organism, in which tooth eruption through the augmented area is still to be made possible. In addition, the capacity and possibilities of the drug delivery function are expanded. Following the concept of in situ TE, MBG and/or hydrogel will be loaded with chemoattractive factors that attract osteoprogenitor cells from the surrounding tissue after release. Therefore, pre-colonization in vitro is avoided. A particular challenge in cleft palate osteoplasty is the insertion of the graft into geometrically complex defects that are difficult to access. For this purpose, an in situ printing technology for the material system is being explored that can be used simply and safely in the operating theater. The project is investigating various material combinations for coextrusion and the release of growth factors from the material system, developing a solution for an in situ printing system that can be used intraoperatively and evaluating the material/application system in vivo in the minipig jaw defect model.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Anja Lode