The integration of biological or tissue engineered cartilage grafts postsurgery remains a significant challenge and is a translational barrier for many otherwise promising cartilage grafts. The focus of this SP is to regenerate the cartilage-to-bone interface, which is composed of hypertrophic chondrocytes within a calcified cartilage matrix, for the purpose of integrative cartilage repair. The presence of such a structural barrier between the healing cartilage and subchondral bone has been shown to be critical for limiting osseous invasion and maintaining the integrity of the repaired cartilage. To this end, our laboratory has developed hydrogel-ceramic scaffolds for the regeneration of the cartilage-to-bone interface.

This collaborative venture focuses on the design and optimization of a hydrogel-ceramic composite scaffold for calcified cartilage formation. In particular, the following key parameters will be evaluated: ceramic chemistry (inert ceramics, such as hydroxyapatite, or bioactive ceramics, such as tricalcium phosphate), ceramic size (microscale particles to nanoscale particles), ceramic particle dose, and hydrogel type (inert gels, such as agarose, or biofunctional hydrogels). These studies will yield essential scaffold design parameters for the osteochondral interface or calcified cartilage formation. It is envisioned that by investigating the effects of calcium phosphate ceramics on cell hypertrophy, and by testing these parameters in a variety of hydrogels, universal design parameters for a mineral-hydrogel scaffold can be elucidated. These discoveries can then be incorporated into current osteochondral graft design, as many of these approaches center on combining a hydrogel phase with ceramics or polymer-ceramic composites.

_{Images courtesy Biomaterials Lab (Rice)}