Abstract:

BACKGROUND: The bionic nano-composite materials have the similar structure and microenvironment to the autologous bone. Thus they are promising to be applied in the clinic.
OBJECTIVE: To observe the feasibility of repairing rabbit tibial defects by the new bionic composite of nano-gelatin-apitate-minocycline
METHODS: Twenty healthy adult New Zealand rabbits were used in this study to establish a 15mm×8mm critical size defect on rabbit tibial bones. All rabbits were randomly divided into experimental (n=16) and blank control groups (n=4). New materials were implanted into the segmental bone defects in the experimental group, but no implant was given to the blank control group. X ray and histological examinations were performed to compare the union of fracture at 2, 4, 8, and 12 weeks postoperatively.
RESULTS AND CONCLUSION: General observations showed that the fractured bone healed at 8 weeks postoperatively in the experimental group, and the moulding was close to normal at 12 weeks. X ray showed that bony callus gradually increased over time was went by in the experimental group, the fractures almost healed and the moulding was finished at 12 weeks postoperatively. No bone defects were repaired and nonunion occurred in the blank control group at 12 weeks postoperatively. Histological examination indicated that the materials began to be absorbed at 4 weeks postoperatively, reconstractured by new bone at 8 weeks postoperatively, and completely repaired at 12 weeks postoperatively in the experimental group. There was no new bone formed in the control group, and the bone defects were filled with the fibrous tissues. The new bionic composite of nano-gelatin-apitate-minocycline can repair critical size defect effectively.