Local microarchitecture affects mechanical properties of deposited extracellular matrix for osteonal regeneration.

Abstract Multiple biomimetic approaches have been attempted to accelerate the regeneration of functional bone tissue. While most synthetic scaffolds are designed to mimic the architecture of trabecular bone, in the current study, cortical bone-like extracellular matrix was regenerated in vitro within organized structures. Biphasic calcium phosphate (BCaP) and hydroxyapatite (HAp) scaffolds were developed with longitudinal microchannels (250 μm diameter) that resembled native osteons in cortical bone. BCaP and HAp scaffolds had a compressive strength of 7.61 ± 1.42 and 9.98 ± 0.61 MPa respectively. The constructs were investigated in vitro to evaluate the organization and stiffness of the extracellular matrix (ECM) formed by human fetal osteoblasts (HFObs) cultured inside the microchannels. The ECM deposited on the BCaP scaffolds was found to have a higher micro-hardness ( h ) (1.93 ± 0.40 GPa) than the ECM formed within the HAp microchannels (h = 0.80 ± 0.20 GPa) (p