Experimental Study Of Staphylococcus Aureus Injection Repairing Skull Defects In Rats With Fibrin Sealant As Carrier

Objective: To study the feasibility of fibrin sealant as carrier of staphy1ococcus aureus injection for repairing bone defects, and avoid the flaws of local injection of staphylococcus aureus injection.Methods: To preparation the complex of fibrin sealant and staphylococcus aureus injection. Eighty Wister rats were randomly divided into four groups: experimental group (n=20), control groupA(n=20), control groupB (n=20) and blank group (n=20). Two 5-mm diameter bone defects were created symmetrically on both sides of the cranial bone in rats. Rars were implanted with the complex of fibrin sealant and staphylococcus aureus injection in bilateral calvarial bone defect in experimental group; with fibrin sealant in control groupA; with staphylococcus aureus injection in control groupB after operation for 1 week (containing the same amount of staphylococcus aureus injection as the experimental group); while nothing was implanted in blank group; Another five rats without any treatment were regarded as normal skull group. After operation for 4 weeks, general observation, radiology observation were performed; after operation for 6 weeks, general observation, radiology observation, histological examination were performed, biomechanics were determined, and compared with normal skull.Results:After operation each group had no significant immune rejection. After operation for 4 and 6 weeks, radiology observation indicated that percentage of new bone forming area in experimental group was higher than in control groupA, B and blank group, and there was statistically significant difference between four groups(P<0.01). 6 weeks later, histological examination revealed that fibrin sealant had been completely absorbed in experimental group and bone defect basically healed, but in control groupA, fibrin sealant had been completely degraded and there were a large number of new bone at the edge of defect, and a small amount of new bone could be seen at the edge of defect in blank group and other parts of defect had been covered by the dense fibrous connective tisssue, and the amount of osteotylus in control groupB lied in between it in control group1 and it in blank group; Biomechanics revealed that maximum load of osteotylus in experimental group were significantly highter than in control groupA&B, and lower than normal skull group (P<0.05); Maximum strain displacement of osteotylus in control groupA&B were significantly highter than in experimental group (P<0.05),and the result of maximum strain displacement of osteotylus had no statistically significant difference between control groupA and control groupB(P>0.05),and it also had no statistically significant difference between experimental group and normal skull group (P>0.05); the ratio of maximum load and strain displacement in experimental group and normal skull group were significantly highter than in control groupA&B, while it in experimental group was significantly lower than in normal skull group, and it in control groupA was significantly higher than in control groupB(P<0.05).Conclusion:Fibrin sealant as carrier of staphy1ococcus aureus injection for repairing bone is feasible , the complex of fibrin sealant and staphylococcus aureus injection can promote the formation of new bone.