EFFECTS OF CHITOSAN/β-TCP MICROSPHERES ON RABBIT CRANIAL AND CONDYLE DEFECTS HEALING: A PRELIMINARY STUDY

Abstract

Two kinds of chitosan/β-TCP microspheres were prepared; one was by a traditional emulsion technique (Group A), and the other was by a high-voltage electrostatic system (Group B). Both of the microspheres exhibited good sphericity and the β-TCP fine particles were well trapped inside the chitosan based particles. After 60-day shaking, Group A and Group B degraded by about 40% and 80% of initial weight, respectively. Two models of bone defects were created in rabbits included for a series of randomized blind pilot study. In the cranial model, two equal 10 mm diameter cranial defects were created. In condyle model, two equal 5 mm femur condyle defects were created on each hind leg, and underwent the same grafting treatment. After 4 weeks of implantation, both the cranial and condyle sites filled with Group A were shown to be surrounded by fibrous tissues with the presence of osteoblasts. In Group B, only condyle site showed the presence of osteoblasts. In contrast, fibrous tissue formation was seen on the control group after 4 weeks of healing. After 8 weeks of implantation, the condyle sites filled with Group A and Group B showed the presence of new bone formation as compared to control group. However, there was no obvious new bone formations in the cranial sites filled with both Group A and Group B. The same events were observed in the cranial sites after 12 weeks of implantation. In contrast, new bone formation was seen on the condyle sites in all three groups after 12 weeks of implantation.