| Osteomyelitis is one of the stickest dieseases in orthopedic department,for its long sick period.Further more,it is probable to lead to chronic sinus tract,scar,bone ununion and infectious bone defect.The basic principle of treating the chronic osteomyelitis is complete focus clearance with adequate use of antibiotics.however,the focus clearance usually brings up the defect of bone tissue,which needs to be repaired by substitutes for bone.The substitutes should be capable of killing the residual bacteria and repairing the bone defect.Presently,the substitutes mainly are classified to inorganic and organic ones.The former,like antibiotics loaded hadroxyappetite and calcium phosphate,are known for their good bio-compatibility,bio-mechanic properties.But for the lack of plasticity,fragility,compressive strength,its use in clinic department is restricted to some extent.The main characteristics of organic ones,polymethyl methacrylate(PMMA),polylactic acid(PLA),polycaprolactone(PCL),for instance,are plasticity and compression resistance.Nevertheless,they lack bioactivities and degradation with the problem of unmatched speed of bone formation.That is why people are seeking one novel kind of bone repair material with adequate bio-compatibility,degradation,plasticity,compression resistance and controlled release.Ag-n HA/PU is based on our previous research by combining Ag-n HA with PU.Ag ion possesses good antibacterial abilities.And it had been proven in our previous study that Ag-n HA/PU is capable of controlled degradation and bone formation.Therefore,we expect that with all these properties,we can provide research evidence for the use of it in clinic department.ObjectiveTo study the silver ion release characteristics and the effect of osteomyelitis curing,for its use for clinic demand in the future.Method1.release characteristics of Ag-n HA/PU material in vitro2.the effect of Ag-n HA/PU for curing osteomyelitisn HA/PU and Ag-n HA/PU materials were implanted in the tibia in the rabbits,at 4d,3w,6w,12 w,treat the rabbits with Micro CT scan and histology examination,along with the functions of liver and kidney.Still,the Ag concentrations are also be tested to discuss its safety.Results1.the release characteristics of Ag-n HA/PU in vitro Ag-n HA/PU behaves well in the deionized water in releasing the Ag ions.2.the effect of Ag-n HA/PU for curing osteomyelitis2.1 Histologistic results have shown that all the materials are far away from the bone tissue and no new born trabecula is seen.The Ag3PO4 particles distributed homogeneously in the 3%Ag-n-HA/PU and 10%Ag-n-HA/PU group and no new born trabecula is found.New born trabecula are founded in n-HA/PU,3%Ag-n-HA/PU and 10wt%Ag3PO4 groups at the time point of 3 week.New born trabecula are detected in the blank control group and n-HA/PU group.A mass of trabecula were found in the 3%Ag-n-HA/PU group.New bone formation was also found in the 10%Ag-n-HA/PU,along the way across the surface of the material at 6 week.Nonconsecutive trabecula were found in the blank group and n-HA/PU group.A big mass of new bone were found in both 3%Ag-n-HA/PU group and 10%Ag-n-HA/PU group at 12 week.Lots of inflammatory cells were found in the blank group and n-HA/PU group.Much collegan was found in both 3%Ag-n-HA/PU group and 10%Ag-n-HA/PU group in HE staining slices.2.2 no significant differences between all the groups on AST,ALT,BUN,Cr at each time point(P>0.05).Ag + concentration in the blood were not detected at each time point.And no abnormal changes were found in heart,liver,kidney,brain.in Ag-n HA/PU groups.It is not detectable concentration of Ag in heart,liver,kidney,brain of Ag-n HA/PU groups.Conclusion1.The bone repair materials of Ag-n HA/PU has a good release effect in deionized water..2.Ag-n HA/PU composite bone repair materials have a good ability to cure infection and the infectious defect.It is one kind of promising material for clinic use to eradicate the osteimyelitis. |
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