Abstract:

BACKGROUND: The bionic nano-composite materials have the similar composition and structure with the autologous bone, thus they are promising to apply.
OBJECTIVE: To observe the effect of repairing rabbit tibial defects by a new bionic composite of heparin-chitosan-hydroxyapatite -minocycline.
METHODS: Twenty healthy adult New Zealand rabbits were used in this study to establish a 15 mm × 8 mm critical size defect on superior tibial bones, and then divided into experiment group (n=16) and blank control group (n=4) at random. A new bionic composite of heparin-chitosan-hydroxyapatite-minocycline was implants into the segmental bone defects of 16 rabbits in experimental group; No implant was given into the other 5 rabbits in the blank group. Gross observation, X-ray and histological examination were performed to observe the repair of bone defects on two groups.
RESULTS AND CONCLUSION: General observations showed the fractured bone healed at 8 weeks postoperation in the experimental group, and the appearance was close to normal at 12 weeks. X-ray showed that bony callus gradually increased when time went by in the experimental group, the fractures almost healed and the moulding finished 12 weeks postoperation. No bone defects were repaired and nonunion occurred in the blank group at 12 weeks postoperation. Histological examination indicated the materials began to be absorbed at 4 weeks postoperation, was reconstructed by new bone at 8 weeks, and completely repaired at 12 weeks in the experimental group. In the control group, bone defects were filled with the fibrous tissues. The new bionic composite of heparin-chitosan-hydroxyapatite-minocycline can repair critical size defect effectively.