| The premise and background of biomaterials or wares to be usedfor implantation in vivo or contacting with blood of human body wasto detect its reliability which was the biocompatibility of thebiomaterials. A novel biomaterial-modified proplylene carbonatewas manufactured by applied chemistry research institute of ChangChun was evaluated its biocompatibility by a series vitro and vivoexperiment according the evaluation criterion and requirement ofmedical apparatus and instruments which was made by theInternational Standard Organization (ISO1099-1:1992)and China .soas to acquire the operative evaluation of cell toxicity test, Acutetest of total body toxicity, pyrogenic test,stimulative test ofskin,Implantational test of this material and establish basementfor the clinical use of it.Materials and Methods1.The preparation of PPC+PHB extract.The material extract was established by the standards ofGB/T16175-1996 and the extracts of the materials was made by thiscondition, media(IMDM or saline):surface or weight of sample(cm2/g)=1:6/0.2 and the condition was 37±1℃48h.2. Test of cell toxicologyHela cells on the logarithm growth period were produced into cellsuspension with ten kinds of different concentration, and thestandard curve of growth and metabolism of the Hela cells of ourlab was established. The number of 6000 cells/well Hela cell wasdefined as the inoculation number was inoculated into 96 pore plateand three plates .Move out the culture medium of IMDM after 24h andthe extracts of materials(concentration of 6cm2/ml,3cm2/ml1.5cm2/ml)negative culture media and positive culture media(100ul/well) wereadded in. After 24, 48 and 72 hours,20ul MTT(5mg/ml) was added inthe 96 pores plate. Then after cultured for 4 hours, the solutionin the 96 pores plate was give up and added in DMSO( 150ul/well)thenstanding in room for 15 minutes. The absorption value of every porewas measured at 490nm wave-length by used a enzyme unite immunemeter. Then the cell proliferation rate and the grade of toxicitywere calculated.3.Pyrogenic testInjected The material extract to the body of the rabbit throughear vein ,the dosage was 10g/kg. and the temperature of materialextract should be 38 ℃ .Measure temperature three time afterinjection and one time every one hour .the. fervescence is the mosthigh temperature subtract the normal temperature .4. Acute test of total body toxicity20 healthy mouse about 20g and half were male were selected anddivided into two groups randomly, their initials body weight wasrecorded. Mouse of the test group wereinjected the extracts of the material through vein, the dosage was50 g/kg. And the control group mice were injected with saline. After24 h,48 h,72 h, the general behavior, toxicity manifestation anddeath number was observed. The change of body weight was observed.5. Hemolytic test10ml of extracts of the material, sterilized distilled water andsaline were acquired and were in water bath at 37℃ for 30 min, then0.2ml anti-coagulated diluted fresh bloodof rabbit was added in each group. After 60 min in water bath, theywere centrifugated for 5minutes (1000prm). The super suspension wasacquired and was measured at 545 urn by use a spectrophotometer6. Stimulation test of skinThe filter papers which were soaked in material extract or salinethat were sticked on the back of the rabbits .cover them withbandage .Move away them after 24h and rash the skin with room waterThen counting scores about the reaction of erythema and dropsy.during 1,24,48 and 72h .7. Implantation testPPC+PHB and PLA were implanted to the back of rabbits and threepoints every side .the side is PPC+PHB and other controlmaterial .The shape of them are cylinder(2×6mm). Random killed 2-3rabbits after 1,4,12,26 and 52w and macroscopic observation thereaction of subcutaneously and muscle then cutting the muscle ofenclosingPPC+PHB and PLA. light microscope observation tissuereaction .fibrous capsule.,inflammatory cell.and other cells afterEosin-campeachy and M dyeing. meanwhile compare with controlmaterial .Result1.Test of cell toxicologyInverted microscope observation culture cell after 1,2and 3d.Thecell numberof positive group obviously reduce and cell pyknosiseven disaggregation .The experiment group and negative group aresimilar that cell population obviously increase. Measured by MTTthe OD of the positive group was lower than the material groups(P<0.05), and there was no difference between the negative groupand material groups.2.Pyrogenic testFervescence is little than 0.6℃of all experiment animals and thetotal amount is 0.2.℃.So the material is fit to the regulation ofpyrogenic detection.3. Acute test of total body toxicityNo death was found in all the mice within the 3 days, and notoxicosis symptom or illefect was found within the 72 hours. There was no difference betweenthe material group and saline group.4. Hemolytic testThe hemolysis ratio of the saline group was 0 percent and thestilled water group was100 percent. The hemolysis ratio of the material was0.94 percent .5. Stimulation test of skinThere is not erythema and dropsy were found. and the primarystimulus count scores is 0 and the primary stimulus index is 0 .after the extract contact with skin in 24,48 and 72h ..6. Implantation testIn earlier period of implantation, acute inflammatory reactionis main part of the organism action. The tissue signature in 4w islittle heterophil granulocyte, lymph-cell and there is raritasfibrous capsule on tissue-material surface. The fibrous capsulebecome more stability after 12w. Compare with 12w the fibrouscapsule become more thin in 26w,and Only little lymph-cell in thesamples.the thickness of wall do not continue increase... Thetissue signature of 52w is almost same with 26w ,the only differentis the fibrous capsule become more tight.ConclusionIt does not induce cytotoxicity to Hela cell;does not has acute toxic to themices;does not contain heat source;does not induce haemolyticus andStimulation effect. So all these results indicate the medical material has goodbiocompatibility and it is a safe medical material .
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