An in-vitro model for the development of mature bone containing an osteocyte network

Bone tissue continuously adapts to changes in mechanical load. This process can also result in a maladaptive ectopic bone response to mechanical insult, known as heterotopic ossification. The pathological differences at the molecular and structural levels are poorly understood. In vivo models exist but can often be too complex to allow isolation of factors which may stimulate disease progression. This thesis presents the development of a biologically self-structuring bone culture system using a fibrin gel which self-organises between two calcium phosphate anchors when seeded with cells. These bioinspired wound analogues are seeded with primary femoral periosteal cells - key players in bone repair and a range of pathologies- and develop longitudinally over time, allowing to study the temporal evolution of bone mineral and microstructure in excess of a year. Raman spectroscopy and XRD revealed that the mineral was hydroxyapatite and associated with collagen, which was organized like the in vivo tissue. The initial stem cell population differentiated to the terminal osteocytic phase, was linked by longitudinal canalicular networks (demonstrated using nanoCT) and remained viable over the year of culture. This work also demonstrated that pharmacological compounds can prevent the progress of ossification, displaying promise for applications in drug screening