Mechanical property of silver-loaded coralline hydroxyapatite bone in the repair of large segmental contaminative radial defects / 中国组织工程研究

ABSTRACT

BACKGROUND:Scholars have made certain progress in the basic and clinical studies regarding antibacterial bone graft materials. OBJECTIVE: To investigate the mechanical property of antimicrobial silver-loaded coral hydroxyapatite bone usingin vitro mechanical experiments and to explore its ability to repair large segmental contaminative bone defects. METHODS:Compression test and three-point bending test were used to evaluate the mechanical properties of silver-load coraline hydroxyapatite, coraline hydroxyapatite and coral. Thirty-six New Zealand white rabbits were selected and randomly divided into four groups to establish right-side large segment of contaminative radial bone defect models. Rabbits in three groups were implanted silver-load coraline hydroxyapatite, coraline hydroxyapatite andin situ autologous bone, and rabbits in the other group were not implanted any material (as control). At 2, 6 and 10 weeks post-operation, the rabbits were sacrificed to take specimens. The repair of bone defects in each group was observed and compared by gross observation, radiographic examination and histological examination. The antimicrobial condition in each group was evaluated by bacteriological examination. RESULTS AND CONCLUSION:There was no significant difference between the mechanical properties of silver-load coraline hydroxyapatite, coraline hydroxyapatite and coral. At the 10th week post-operation, X-ray and histological observation showed mature bone tissues in the silver-load coraline hydroxyapatite bone group. A large number of lacunae and mature bone cels were visible in bone tissues. Haversian system was visible. Most of the materials were degraded, and there was only a smal amount of residual material. Partial recanalization was visible in bone marrow cavity. The repair effect of silver-load coraline hydroxyapatite bone group was similar with the autologous bone group, and better than the coraline hydroxyapatite group and the control group. Bacteriological examination showed that the silver-load coraline hydroxyapatite had good antibacterial ability. These results demonstrate that the silver-load coraline hydroxyapatite has good mechanical properties and antibacterial properties, which can be used to repair large segmental contaminative bone defects.