Electrospun Silk Nano-Fiber Combined with Nano-Hydoxyapatite Graft for the Rabbit Calvarial Model

ABSTRACT

PURPOSE: The objective of the present study was to determine the capability of electrospun silk fibroin as a biomaterial template for bone formation when mixed with nano-hydoxyapatite in vivo.MATERIALS AND METHODS: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter 8.0 mm). The electrospun silk fibroin was coated by nano-hydroxyapatite and grafted into the right parietal bone (experimental group). The left side (control group) did not receive a graft. The animals were sacrificed at 6 weeks and 12 weeks, humanly. The microcomputerized tomogram (microCT) was taken for each specimen. Subsequently, they were undergone decalcification and stained for the histological analysis.RESULTS: The average value of all measured variables was higher in the experimental group than in the control at 6 weeks after the operation. BMC in the experimental group at 6 weeks after operation was 48.94 +/- 19.25 and that in the control was 26.17 +/- 16.40 (P = 0.027). BMD in the experimental group at 6 weeks after operation was 324.59 +/- 165.24 and that in the control was 173.03 +/- 120.30 (P = 0.044). TMC in the experimental group at 6 weeks after operation was 19.50 +/- 6.00 and that in the control was 10.52 +/- 6.20 (P = 0.011). TMD in the experimental group at 6 weeks after operation was 508.88 +/- 297.57 and that in the control was 273.54 +/- 175.91 (P = 0.06). Gross image of both groups showed higher calcification area at 12 weeks than them in 6 weeks. The average value of microCT analysis was higher at 12 weeks than that in 6 weeks in both groups. BMC in the experimental group at 12 weeks after operation was 51.21 +/- 8.81 and that in the control was 33.47 +/- 11.13 (P = 0.010). BMD in the experimental group at 12 weeks after operation was 323.39 +/- 21.54 and that in the control was 197.75 +/- 76.23 (P = 0.012). TMC in the experimental group at 12 weeks after operation was 21.44 +/- 5.30 and that in the control was 13.31 +/- 4.17 (P = 0.008). TMD in the experimental group at 12 weeks after operation was 524.47 +/- 19.37 and that in the control was 299.60 +/- 136.20 (P = 0.016).CONCLUSION: The rabbit calvarial defect could be successfully repaired by electrospun silk nano-fiber combined with nano-hydroxyapatite.