In vivo efficacy of carbonate apatite based scaffold in a New Zealand white rabbit

Abstract

Biodegradable scaffolds with good tissue responses with the bone are one of the crucial characteristics for application in bone tissue engineering. Although hydroxyapatite (HAP) showed excellent tissue response towards the bone, HAP cannot be resorbed by osteoclasts when implanted. Carbonate apatite (CAP), which contains 4–8 wt% in human bone, has attracted immediate attention as an artificial bone substitute for tissue regeneration. A multifunctional CAP-based scaffold (HieCAP) has been developed in our previous study. However, HieCAP scaffolds have not been tested in an animal model to evaluate the prototype's performance compared to the HAP scaffold following transplanted into an animal model of bone defects. In this study, twelve New Zealand white rabbits were grouped (n = 3) as group 1 (implanted with bone defect as control and HieCAP) and group 2 (implanted with HAP and HieCAP). The rabbits were monitored if any side effects following scaffold transplantation. After pre-determined time points, rabbits were euthanized. The physical changes to the implanted site were observed using digital x-ray radiographical and computerized tomography at 6 and 12 weeks of post-implantation. All the rabbits fully recovered after the surgery and had inappetence on the first day of surgery. There are no significant differences in the body weights and body temperature of rabbits in all groups until 12 weeks. Digital radiography did not show adverse effects on the bone. The results of the present research revealed that with the unique hierarchical architecture of HieCAP, it can be used as a bone graph substitute.