Osteoblastic Differentiation of Functionalized Biphasic Hydroxyapatite and b-Tricalcium Phosphate with Recombinant Human Growth and Differentiation (rhGDF-5)

The purpose of this research was to examine the effect of biphasic hydroxyapatite and b-tricalcium phosphate (HAp-bTCP) immobilized GDF-5 to assess the hypothesis that osteoblast is enhanced and bone formation is promoted when compared to biphasic HAp-bTCP in vitro and in vivo . First, we characterized the release profiles from HAp-bTCP and tested their cell viability, differentiation. After that, we loaded GDF-5 to HAp-bTCP. In the animal study, 4 full thickness critical-size calvarial defects were prepared in a total of 16 male rabbits. The cranial defects were filled with HAP-bTCp, or heparized HAP-bTCP. At 5 and 10 weeks, dissected specimens were processed for histological and histochemical analysis. GDF-5 was considered to be released in a sustained mode from HAp-bTCP. In vitro results provided that the proliferation and differentiation of MG-63 cells to HAp-bTCP-GDF-5 was higher than that of the control group. In addition, in vivo animal studies showed that HAp-bTCP-GDF-5 has a significant improvement to bone formation. HAp-bTCP-GDF-5 is thought to be an excellent biomaterial that delivers osteogenic differentiation factors such as GDF-5, and GDF-5 can be possibly useful as an effective alternative to avail new bone formation.