Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Etschmaier, V.
An ex vivo organotypic rat femur slice culture – A novel tool for the investigation of bone regeneration and postnatal endochondral development
Doktoratsstudium der Medizinischen Wissenschaft; Humanmedizin; [ Dissertation ] Medizinische Universität Graz; 2024. pp. 144
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Lohberger Birgit
- Ücal Muammer
- Weinberg Annelie-Martina
- Altmetrics:
- Abstract:
- Postnatal longitudinal bone growth primarily occurs within the growth plate (GP) through the proliferation and osteogenic differentiation of chondrocytes via endochondral ossification. When changes in the GP organization occur due to injuries, illness, or as a result of therapy, this can lead to significant complications concerning the skeletal development. Regenerative processes following sustained injury and illness that diverge from restoring the original state can have significant negative complications such as premature closure of the GP or growth arrest resulting in limb shortening and/or angulation deformity. Currently, no preventative biological treatment is available for the GP pathological processes. One reason is the still no fully understood pathological regeneration mechanism, which leads to the growth-related issues. The lack of new, easy-to-handle research models that allow real-time investigation of the pathological regeneration process is still missing. In this dissertation, I modified an ex vivo femur organotypic model (OTC) to investigated pathological regeneration processes following 1) GP injury similar to Salter Harris III and IV and 2) particle irradiation with proton or carbon ions (C-ions) at the MedAustron facilities. I utilized a 300 µm thick OTC and exposed the culture to the two experimental conditions, respectively, with subsequent in vitro cultivation for up to 15 days. I conducted electron microscopy, gene expression analysis, live/dead staining, histological examinations, and immunohistochemistry and analyzed key markers of endochondral ossification. Regarding the GPI investigation, we observed regeneration processes coupled with trauma-induced alteration of structural architecture and organization, as well as a pronounced impairment of chondrocyte maturation with a preference for chondrogenesis over osteogenesis within the ex vivo organotypic GPI model. Moreover, following PT, pathological regeneration processes indicated an initial loss of proliferating chondrocytes with the formation of chondrocyte clusters, reduced osteogenesis and chondrogenesis coupled with a disruption in extracellular matrix (ECM) maturation/composition. In both studies, the results obtained from the ex vivo femur organotypic model are comparable to the in vivo situation, making this new bone development and regeneration model a powerfool tool to further advance the scientific knowledge.