A novel ex vivo culture system for studying bone repair.

Repair of large bony defects still remains a challenge for surgeons. Hydroxyapatite (HA) is well known for its biocompatibility and osseoconduction properties in the osseous environment. In this study the biofunctionality of a newly developed scaffold comprising of collagen and HA, with variable macropores was examined. The biological response was evaluated using primary human osteoblast cells (HOBs). Cell infiltration, proliferation and differentiation were assessed. The results showed that HOBs were able to migrate from the collagen into the HA pores with greater cell migration and infiltration observed in those scaffolds with larger pores. Furthermore, it was shown that Alkaline Phosphatase, a differentiation marker for HOBs was enhanced as the average macropore size increased. This in vitro model provides a more relevant method of testing the biofunctionality and migration ability of cells at a trauma site following implantation in bone and cartilage.