Fabrication of 3D Bioprinted Bi-Phasic Scaffold for Bone-Cartilage Interface Regeneration.

Treatments for osteochondral defects (OCDs) are mainly palliative and, with the increase in this pathology seen among both young and elderly people, an alternative treatment modality is sought. Many tissue-engineered strategies have been explored for regenerating the cartilage-bone interface; however, they generally fall short of being ideal. Although cell-laden hydrogel scaffolds are a common approach for bone and cartilage tissue regeneration, they usually lack homogenous cell dispersion and patient specificity. In this study, a biphasic 3D bioprinted composite scaffold was fabricated for cartilage-bone interface regeneration. To overcome the shortcoming of both materials, alginate-gelatin (A-G) hydrogel was used to confer a naturally occurring environment for the cells and polycaprolactone (PCL) was used to enhance mechanical stability, thus maximizing the overall performance. Hydroxyapatite fillers were added to the PCL in the bone phase of the scaffold to improve its bioactivity. Physical and biological evaluation of scaffolds in both phases was assessed. The scaffolds demonstrated a desirable biological response both singly and in the combined PCL/A-G scaffolds, in both the short term and longer term, showing promise as an interfacial material between cartilage and bone.