ABSTRACT
BACKGROUND:To obtain a more ideal bone substitute material, nano-hydroxyapatite/silk fibroin composite material has been prepared in the preliminary experiments. OBJECTIVE:To investigate the effect of nano-hydroxyapatite/silk fibroin composite material for repair of bone defects. METHODS:Thirty healthy adult rabbits were randomly divided into two groups, and unilateral middle and distal femoral bone defect models were prepared. The experimental group was implanted with nano-hydroxyapatite/silk fibroin composite material, and the control group was implanted with pure hydroxyapatite. At 4, 8, 12 weeks after surgery, the femur was taken from each rabbit for gross, X-ray, biomechanical and histological examinations. RESULTS AND CONCLUSION: In both two groups, biomechanical strength was gradualy increased with time, but the biomechanical strength was higher in the experimental group than the control group at different time points (P < 0.05). At 12 weeks after surgery, in the experimental group, the bone graft had the smooth surface and exhibited normal color with no difference from the surrounding bone, the artificial bone material was completely absorbed and degraded, and bone defects were completely healed; in the control group, the bone graft had no smooth surface on which the bone cortex was continuous and showed unclear boundary with the surrounding bone tissues, the artificial bone materials were incompletely degraded, bone defects were connected by the caluses, the artificial bone materials were closely in conjunction with the surrounding bone tissues, and bone defects were partialy repaired. These findings indicate that the nano-hydroxyapatite/silk fibroin composite artificial material can promote bone defect repair and exhibit stronger osteogenic ability.