Comparative Study of Bone Repair Using Porous Hydroxyapatite/ β-Tricalcium Phosphate and Xenograft Scaffold in Rabbits with Tibia Defect

Bone tissue engineering requires materials that are biocompatible, mechanically suited for bone function, integrated with the host skeleton, and support osteoinduction of the implanted cells for new bone formation. The aim of this study was to compare the osteogenic potential of xenograft with hydroxyapatite/β- tricalcium phosphate (HA/β-TCP) scaffold.

New Zealand rabbits (n = 9) were divided into 3 groups. Osteoblast cells were originally isolated from rabbit iliac crest and cultured in DMEM/F12. After creating a critical-sized defect (2 × 3 cm) in rabbit tibia bone, the defect was filled with an implant of HA/TCP with osteoblasts and xenograft in the hole of left (as control) and right tibia, respectively. The new bone formation and the development of bone union within the defect were evaluated by x-ray images and eosine and hematoxylin staining at 4, 8, and 12 weeks post-operation.

The bone partially formed in both groups was filled with osteoblast cultured on porous implants at 4 weeks. Over time, progressive bone regeneration was observed inside the pores. Moreover, a progressive vascular ingrowth and progressive integration with the host bone were obvious in xenograft when compared to HA/β-TCP. A good integration between the xenograft implants and the bone was observed radiographically and confirmed by histological section.

The result showed that the bone defect can be repaired using both synthetic and xenograft implants. However, the xenograft showed a better osteointegration as compared to HA/β-TCP scaffold.