Biocompatibility Of Nanohydroxyapatite/Polyamino Acid Composite

Objective:To investigate the biocompatibility of nanohydroxyapatite/polyamino acid composite for bone transplantation and internal fixation.Methods： In vivo and vitro experiment were estimated for thebiocompatibility of nanohydroxyapatite/polyamino acid composite asfollows,①cytotoxinic test,bone marrow mesenchymal stem cell(BMMSCs)were incubated with the composite,the morphology of the cells wasobserved by inverted phase contrast microscope, the rate of adhesion cellsand CCK-8were tested.②acute toxic test was divided into2groups (n=10)including20KM mice weighted20~23g,the extracts and physiologicalsaline were injected to mice with50g/kg,the toxicity manifestation wereobserved.③hemolytic test consist3groups,0.2ml anticoagulant dilutedfresh rabbit blood was added to10ml extracts, sterile distilled water andphysiological saline each,the percentage of hemolysis was examined.④pyrogen test,3rabbits weighted2.3~2.5kg were injected in vain with10ml/kg extracts, the difference in temperature between the normal bodytemperature tested and the ones per hour in the next continues3hours.⑤bone marrow micronucleus test,30KM mice weighted20~23g were divided into3groups, extracts,cyclophosphamide and physiological salinewere injected to mice with100mg/kg twice at24hours intervals, thenumbers of micronucleated polychromatic erythrocytes and polychromaticerythrocytes were observed, the frequency of micronucleus was calculated.Results： the cell morphology of rabbit BMMSCs seedednanohydroxyapatite/polyamino acid composite is normal as the controlgroup, the rate of adhesion cells and cell proliferation have no apparentdifference,and the reaction of animals in the group injected the extracts isno more than the control group in the acute toxicity test, the hemolysis rateof the composite is1.4%in the hemolytic test,the rise temperature ofeach rabbit is less than0.6℃,the temperature of3rabbits rise1.4℃altogether, the frequency of micronucleus were0.0780%,0.0495%and0.931%in the composite group,the negative control group and the positivecontrol group in the mouse bone marrow mircronucleus test.Conclusion： nanohydroxyapatite/polyamino acid composite hadgood biocompatibility with rabbit BMMSCs, and the composite was of noacute toxicity,no pyrogern,no hemolytic effect and no genotoxicity bymouse bone marrow mircronucleus test.