Thesis background: Osteoarthritis (OA) is a debilitating joint disease whose causes are not fully understood. To deepen understanding of the changes in joint tissues that occur as a result of age and OA-related degeneration, new techniques for cartilage characterization are needed. Neutron and synchrotron phase-contrast tomography are techniques showing promise in this regard. Neutron tomography allows for hydrogen-sensitive imaging of tissue, allowing one to characterize tissue matrix density. Additionally, the technique shows contrast between H2O and D2O, allowing for studies of water flow and exchange. Phase-contrast synchrotron tomography allows for imaging interfaces in tissue, showing cells and fibers in a similar manner to histologically stained slices, but in full 3D. The technique is also rapid and nondestructive, allowing for both in-situ experiments as well as combination with other techniques.
Objectives: The goal of the PhD project is to evaluate the ability of neutron and phase-contrast tomography to characterize knee joint tissues in novel ways. The goal is to explore applications of these techniques to understand structural and mechanical changes in cartilage and meniscus during different stages of OA development.
Experiments performed: Neutron tomography of human articular cartilage samples (MENIX biobank) were performed during summer 2021. Samples were placed in sealed tubes to prevent drying and imaged under static conditions, which revealed depth-wise differences in tissue matrix density. Synchrotron tomography experiments were performed in spring 2022, samples (human articular cartilage, MENIX biobank) were imaged in PBS. Synchrotron images are currently being analyzed via segmentation and region properties to reveal cell properties such as density and orientation as well as their depth-wise variation.
Future experimental plan: One new neutron tomography experiment is planned for fall 2023, aiming to image water diffusion in cartilage by placing bovine articular cartilage and meniscus samples in a canister that is flooded with heavy water at the start of the experiment.
Gällande start-/slutdatum2021/03/15 → …