Experimental Research On The NBD Peptide For The Treatment Of Chronic Osteomyelitis In Rabbit Mandible

Part1Study on the establishment of experimental chronic osteomyelitis in rabbit mandibleObjectives:This study was performed to analyze the establishment of experimental chronic osteomyelitis in rabbit mandible.Methods:Twenty-two healthy New Zealand white rabbits were used in this study.0.1ml5%sodium morrhuate and0.1ml5.0×108cfu/ml Staphylococcus aureus suspensions were injected into the bone defect in the lateral of inferior border of mandible near to the middle joint of the mandible in sequence. The bone defect was sealed with bone wax to prevent bacterial leakage into the surrounding soft tissues and no antibiotics for prevention of bacteremia. The experimental staphylococcus aureus osteomyelitis in rabbits was evaluated by clinical,radiologic,bacteriologic and histologic parameters at the6th week after infection.Results:①All rabbits in poor mental health showed slow weight gain with drinking much water and losing of apptite. Degrees of soft tissue swelling could be seen from the surgical regin which presented purulent secretions and granulation tissue. Bone defect area was irregular and presentation of defect expansion at early phase,whereafter bone defect area with the new bone formation made the appreance of narrowing trend.②Six weeks after surgery,dual-energy x-ray showed much difference between bone mineral density of surgical area and that of contralateral bone area.Bone mineral density was increased from six weeks to fourteen weeks and no Significant difference in the variation of BMD in surgical area (P>0.05).③Increased destruction of bone dissolution and the expansion of bone defect was detected through CBCT detection which demonstrated that bone defect showed narrowing trend from six weeks to fourteen weeks and was still observed at the fourteen week.④Staphylococcus aureus could be found from surgical region at the sixth week and was still detected at the fourteenth week.⑤Pathological sections showed lymphocyte,neutrophilic granulocyte and plasma cell infiltration and sequestration and presented the pathology of chronic osteomyelitis at the fourteenth week.Conclusion:The establishment of experimental chronic osteomyelitis in rabbit mandible can be accomplished by injection of Staphylococcus aureus suspensions into the bone defect in the lateral of inferior border of mandible near to the middle joint of the mandible. Part2Study on the local injection of NBD peptide into the bone defect for the treatment of chronic osteomyelitis in rabbit mandibleObjectives:This study was performed to analyze the local injection of NBD peptide to the bone defect for the treatment of chronic osteomyelitis in rabbit mandible.Methods:Eighteen healthy New Zealand white rabbits were used in this study. The models of chronic osteomyelitis induced by the local injection of NBD peptide into the bone defect of rabbit mandibles were randomly divided in to three groups.No therapeutic measurement for models was used in the first group while only debridement in the second group and debridement combined with local injection of NBD peptide to the bone defect in the third group.The methods of the dual-energy x-ray analyzation,CBCT detection and making pathological sections were used to evaluate the effects of different intervenes.Results:Dual-energy x-ray showed that the BMD in the surgical region of the first group was0.51±0.13(g/cm3) at the4th week and0.58±0.21(g/cm3) at the8th week while that of the third group was0.68±0.11(g/cm3)at the4th week and0.91±0.15(g/cm3)at the8th and that of the second group was0.59±0.19(g/cm3) at the4th week and0.72±0.13(g/cm3) at the8th week.It was demonstrated that the BMD in the surgical region of the third group presented the fastest rising among the three groups while that of the first group making the slowest rising.There was one model showing progressive increasement of bone destruction and dramatic decline in BMD in the first group.It was found that through CBCT detection the speed of bone defect narrowing in the third group was the highest among three groups while that of the first group presenting the lowest.There was significant difference in bone defect variation among the three groups.(P<0.05).After making pathological sections from three groups,we found that the sections in the first group showed lymphocyte,neutrophilic granulocyte and plasma cell infiltration and sequestration and presented the pathology of chronic osteomyelitis at the eighth while pathological sections in the third group showed mild inflammation at the fourth week.Conclusion: The local injection of NBD peptide into the bone defect of the rabbit mandible could make the treatment of the chronic osteomyelitis in rabbit model.