血液相容性高分子材料的凝血機(jī)制

血液相容性高分子材料的凝血機(jī)制

poliwelling國(guó)際習(xí)慣法預(yù)算部門、自然和藝術(shù)區(qū)域的住宅分配被認(rèn)為是消耗的。subjects,suchaslifescience,materialscience,medicineandengineering.Narrowsensebiomaterialsrepresentbiomedicalmaterials.Accordingtoproperties,biomedicalmaterialscanbeclassifiedintonaturalbiomaterials,metalmaterials,inorganicnon-metalmaterials,polymericmaterialsandhybridizedbiomedicalmaterials.Polymericmaterialsthatareimplantedintoorganisminvivoshouldhavetwobasicperformances:medicalfunctionandbiocompatibility.Thisincludesrequirementsofphysicalandmechanicalfunction,chemicalstability,toxicity,andprocessing.Medicalfunctionrepresentsdiagnosticortreatmenteffectsofmaterialsbindingwithbiologicalsystems.Biocompatibilityisdegreeofcompatibilitybetweenmaterialsandlivingorganisms,includinghemocompatibilityandhistocompatibility.Biocompatibilityisthemostimportantcharacterofbiomedicalmaterialsdifferentfromothermaterialsandregardedasthebasicevidencefortheevaluationofbiomedicalapplication.Therefore,biocompatibilityisafocusinstudiesofbiomedicalmaterials.數(shù)據(jù)和存儲(chǔ)biocompati效/agpo-inrt-pcrpubli分離,pub/publi分離,publi分離,publi域Acomputer-basedonlinesearchofPubMeddatabaseandWanfangdatabasewasperformedforarticlespublishedfrom1953to2011withkeywords“biocompatibility,bloodcompatibility,bio-inertsurface,bio-activesurface”.rectity法律數(shù)字Articlesrelatedtohemocompatibilityofpolymericmaterialsanddesignofanticoagulantmaterialsandpublishedrecentlyorinauthoritativejournalswereselected.Repetitivestudieswereexcluded.Atotalof91articleswerecollected,including21Chineseand70Englisharticles.Studiesnotcloselycorrelatedwiththeinclusioncriteria,oroutdatedandrepetitivearticleswereexcluded.Therefore,33articleswereincluded.非美ocompatibc反應(yīng)The33articleswerefurtheranalyzed.Articlesdiscussedclottingmechanismofbiocompatiblematerials;articles[4-31]discusseddesignofanticoagulantmaterials;articles[32-33]discussedmaterialsurfaceendothelialization.trt基于coagulationofficiciciciciencpa的trtombositrtombosiHemocompatibilitymeansthatmaterialscontactwithblooddonotresultinplasmaproteindegenerationorbloodcoagulationorthrombosis,ordamagebloodeffectivecomponents.主要程序特點(diǎn)Whenbloodflowsinbloodvesselswithendothelialcellsasinnerwall,bloodcoagulationdoesnotoccur.Afterpolymericmaterialsenterorganismandcontactswithblood,bloodflowandbloodvesselwallarechanged,andthematerialsarerecognizedasforeignbodybytheorganism,resultingincoagulationfollowingaserialcomplicatedinteractionbetweenthem.ThisprocesscanbedescribedbyFigure1.First,micromoleculesandplasmaproteinadheretothesurfaceofmaterials,forminganadsorptionlayerofprotein.Thisisarapidprocesswithinseveralseconds.Thesurfacepropertiesofmaterialsgreatlyinfluenceamount,composition,andstructureofproteinadsorptionlayer,whichisimportantforthrombosis.Subsequently,proteinsadheredatthesurfaceofmaterialsdegenerateandactivate,andinducethrombosisbyactivatingbloodcoagulationfactors,plateletadherenceandredbloodcelladherenceinthepresenceofCa2+.Activationofbloodcoagulationfactorsandplateletadherenceplayamajorroleinthisprocess,andtheyinteractwitheachother.Inaddition,biologicalsystemhasanticoagulantsystemnegativefeedback,whichisalsoinfluencedbysurfacepropertiesofmaterials,andsynergizewithcoagulationsystemtodeterminespeedanddegreeofcoagulationreactionofmaterialsurface.加入細(xì)胞系統(tǒng)和雙重標(biāo)準(zhǔn)下的whill-pcctoring,grafting.案例見表4Materialsthatdonotinduceirreversiblethrombosisaftercontactingbloodareregardedasanticoagulantproperty.Accordingtoclottingmechanismofmaterialsurface,inhibitionorblockinganystepofthrombosiscanresultingoodanticoagulanteffects.Currently,designofanticoagulantpolymericbiomaterialsincludesseveralaspects[4,5,6,7,8,9,10,11,12].Surfacegraftmodificationofmaterials:thesurfacegraftmodificationistoreduceinteractionofmaterialandbloodcomponents,inhibitplasmaproteinadherence,andimprovehemocompatibilitybygraftinghydrophilicorhydrophobicgroups.Materialswithhighhydrophilicityexhibitexcellentanticoagulationbecauseinterfacefreeenergyissignificantlyreduced,decreasinginteractionofmaterialsurfaceandvariouscomponentsinblood.Materialswithhighhydrophobicityalsoexhibitexcellentanticoagulationbecausethesurfaceenergyislow,resultinginminimalinteractionwithbloodcomponents.Therefore,surfacegraftingtochangehydrophilicityandhydrophobicityofmaterialsisanimportantapproachtoimproveanticoagulantpropertyofpolymericmaterials.Varioussurfacegraftingmethodshavebeenused.Forexample,acrylamide,methacrylamideandotherhydrophilicmonomershavebeengraftedtopolyurethane,polypropylene,polytetrafluoroethylene,andsiliconrubber.Hemocompatibilityevaluationshowedthatthemodifiedsurfacehasgoodanticoagulantproperty.Interestingly,SPUgraftedwithperfluoroalkyl,extremelyhydrophilicpolyurethane,exhibitedrelativeanticoagulantpropertyInaserialofstudiesofhydrophilicsurface,anticoagulantmaterialswithlongPEOgraftingchainsurfacehavearousedincreasingattention.AccordingtothehypothesisproposedbyNagaokaetal,PEOisakindofmoleculechainwithhighhydrophilicityandflexibility,soitcanbindwatertoformhydratedPEOchain,whichsuppressesbloodcomponentsadherencethroughsterichindrancerejectioneffect.Inaddition,rapidmovementofhydratedPEOinfluencesfluidmechanicsofblood-materialregionandblocksproteinadherenceanddegenerationonmaterialsurface.Furtherstudiesindicatethatanticoagulantpropertyofmaterialsisnotsimplydependingonhydrophilicityorhydrophobicity,butinfluencedbytheirbalance.Thismaybebecausematerialswithbalancedhydrophilicityandhydrophobicityaresimilartonaturalhydrogelinhumantissue.Materialsurfaceloadingelectriccharge:manybloodcomponents,suchashemoglobin,platelet,someplasmaprotein,areelectronegativityinbloodandvesseinnerwall.Therefore,electrostaticrepulsionmayinhibitplasmaproteinandplateletadherencetobenefitanticoagulation.Anionmodifiedsurfacehasbeenextensivelystudiedtoimproveanticoagulantpropertyofmaterials.However,infact,duetocationinadhesionproteinlayeronmaterialsurfaceandblood,ithasmanylimitationstodesignanticoagulantmaterialsbasedonmaterial-bloodelectrostaticinteraction.Biolizationofmaterialsurface:coagulationandanti-coagulationinorganismisadynamicbalancesystem.Avarietyofbioactivesubstanceshavehighanticoagulantactivity.Therefore,loadingthosebioactivesubstancesonmaterialsurfacethroughcovalentbonding,ionicbonding,crosslinkingandadherencehasbecomeaneffectivemethodforimprovinghemocompatibilityofmaterials.Accordingtoanticoagulantmechanismofsurfaceloadingbioactivesubstances,thematerialscanbeclassifiedintotwotypes:onetypeofanticoagulantmaterialssurfaceloadheparin,prostaglandin,albuminandotheractivesubstancestoinhibitactivationofvariousthrombinogensandblockplateletadherence.Inparticular,alargenumberofstudiesfocusonheparinizedpolymericmaterials.Theothertypeofanticoagulantmaterialisfibrinolyticmaterial,whosesurfaceloadsurokinase,fibrinolysin,andstreptokinasetodissolvethrombusonmaterialsurface.Studiesregardingthistypeofmaterialsarefew,buttheyhavearousedmoreandmoreattentionAnticoagulationandfibrinolysisaretwoimportantcharactersofmaterialswithhemocompatibility,sorecentstudieshaveattemptedtodesignanovelhemocompatiblepolymericmaterialsusingsubstanceswiththetwoactivities.Inaddition,basedonactivefunctionalgroupsandactivefragmentsofnaturalanticoagulantandfibrinolyticsubstances,modifyingsurfaceofmaterialsusingsulfonicgroup,sulfanilamide,carboxylicacidandphospholipidpolargroupisalsoaneffectivemethodtoobtainhemocompatibility.Microphaseseparationofmaterialsurface:tunicaintimacontactingbloodiscomposedofepithelialcells.Cellmembraneisthecorepartofcellsurfacestructure.Accordingtobiomembranefluidmosaicmodel,thebiomembraneskeletonislipidbilayer,withproteinmosaicism.Thenonpolargroupsoflipidbilayerareoppositeandpolargroupsareoutward,forminghydrophilicregion.Thehydrophilicregionandproteinhydrophobicregionconstructmicrocosmicnon-homogeneousphasestructure.Therefore,microphaseseparationofmaterialsurfaceisalsoeffectivetoobtainhemocompatibility.Alargenumberofstudiesonsegmentedpolyetherurethanedemonstratedthatmaterialswithmicrophaseseparationstructures,especiallywithbalancedhydrophilicandhydrophobiccomponents,exhibitgoodanticoagulantproperty.Inregardingtotheanticoagulantmechanismofthistypeofmaterials,someresearchersproposed“coveringcontrolhypothesis”.Thatis,whenmicrophaseseparatedmaterialscontactblood,theyabsorbplasmaprotein.Proteinswithdifferenthydrophilicityandhydrophobicityareselectivelyadheredtodifferentmicroregions.Thiskindofspecificproteinadherencelayercannotactivateglycoproteinonplateletsurface,soplateletdoesnotrecognizethemasforeignsubstance,therebyinhibitingcoagulation.Endothelializationofmaterialsurface:surfaceendothelializationisanoveltendencyofanticoagulantstudies.Endoth