生物材料 BiomaterialsPPT课件.ppt

1,Biomaterials,2,Biomaterials,Non-viablematerialusedinamedicaldeviceintendedtointeractwithbiologicalsystemsMaterialintendedtointeractwithbiologicalsystems,3,BiomaterialsScience,PhysicalandbiologicalstudyofmaterialsandtheirinteractionwiththebiologicalenvironmentSynthesisOptimizationTestingBiologyofhost-materialinteractions,4,Ratner(1993)characterizedbodyresponsetothesematerialsas“blah”NonspecificSluggishkineticsBroadspectrumofactiveprocessesoccurringProteins200+tochoosefromCells(neutrophils,macrophages,platelets)welladaptedtorespondtotheseproteins,5,Whatweget,Whatwereallywant,6,DevelopmentofengineeredsurfacesthatelicitrapidandhighlyprecisereactionswithcellsandproteinsTailoredtospecificapplicationResistancetobloodclottingResistancetobacterialinfectionNormaluncomplicatedhealing,7,BiomaterialsHistory,“Herosurgeons”RidleyandIOLsHipandkneeprosthesesCanadianconnectionKidneydialysisBreastimplantsVasculargraftsStents,8,TheTerylene,Orlonornylonclothisboughtfromadrapersshopandcutwithpinkingshearstotherequiredshape.Itisthensewnwiththreadofsimilarmaterialintoatubeandsterilizedbyautoclavingbeforeuse.,9,TheCurrentStateofAffairs,MedicaldevicesareregulatedbytheFDASomedevicesaregrandfatheredbasedonbeingavailablepriortothelegislationintroductionClassifiedbasedonsafetyandpotentialimpacttohumanhealth,10,MaterialsCommonlyUsedinBiomaterialsApplications,SyntheticPolymersHydrogelsPolyurethanesSiliconebasedmaterialsTeflonDacronPoly(ethyleneoxide)DegradablematerialsNaturalPolymersandOtherNaturalMaterials,11,MetalsCeramics,glassesandglass-ceramicsPyroliticCarbonComposite,12,MaterialsandMedicalUses,13,TheBiomaterialsScientist:AJackofAllTrades,ComputationalchemistryMolecularbiologySurfacephysics/chemistryNanofabricationMaterialsscience,14,MaterialsProperties,BulkSurface,15,MechanicalPropertiesofMaterials,16,ElasticBehaviourofMaterials,Solidmaterialsubjectedtotensileforcewillextendinthedirectionoftractionbyanamountproportionaltotheload,17,StressandStrain,ExtensionforagivenloadvarieswithgeometryandcompositionNormalizationofloadanddeformationtoallowcomparisonofdifferentmaterialsNormalizedload(force/area)isstress(s),normalizeddeformationisstrain(e)Stressstraincurveisgeneratedfromthisdata,18,TypicalStressStrainCurve,19,OtherProperties,TensionandcompressionAreasupportingtheloadisperpendiculartotheloadingdirection,changeinlengthisparalleltooriginallengthShearAppliedloadisparalleltotheareasupportingit,20,TensileandShearModulus,21,MechanicalTesting,22,OtherBulkProperties,PorosityPermeability,23,SurfaceProperties,Concernedwithfunction(relatedtodesign),durability(relatedtobulkproperties)andbiocompatibility(relatedtosurfaceproperties),24,Biocompatibility,OverusedtermDefinedasTheabilityofamaterialtoperformwithanappropriatehostresponseinaspecificapplicationTheexploitationbymaterialsoftheproteinsandcellsofthebodytomeetaspecificperformancerequirement,25,SurfacepropertiesdirectthebiologicalresponseNottoxicologyMechanicalandfunctionaldesign,whilecritical,arenotcentraltobiocompatibility,26,TheSurface,SurfaceofamaterialisinvariablydifferentfromitsbulkThereisnotmuchtotalmassonasurfaceMicroelectronicsexample:1cm3cubeofTicontainsa100layerofoxide.Thiscanbecomparedtoa5mwidebeachoneachcoastoftheUSSurfacesreadilycontaminatewithcomponentsfromthevapourphase,27,Figure2:ChangestoPHEMA,28,Figure3Ratner,29,So,WeneedtocontrolthesurfaceCreateasurfacethatmimicsthenativebiologyinordertodevelopmaterialsthatare“biocompatible”Needtocharacterizethesurface,30,Biomimetics,ApproachesthatmimicorreplicatethenaturalfunctionoftissuesareoftenthemostsuccessfulComplexityofnaturaltissuesandorgansisstillfarbeyondtheabilityofscienceforreplicationPrecisefunctionofeveryaspectofthetissueororganisnotknownGeneralconceptshaveemergedfromstudyofstructuralbiologythatprovidedesignstrategiesandguidance,31,CellsaregeneticallyprogrammedtobuildorgansandtissuesCellsproduceproteins,polysaccharides,glycoproteins,lipidsthatassembleintocompositeextracellularmatricesCellscommunicateviagrowthfactorsandtheirrecruitmentBloodvesselsplayacrucialroleintissuegrowthbyprovidingnutrients,ameansforwasteremovalandasupplyofadditionalcellsNervoussystemisresponsiblefortheintegrationandcontrolofallofthebodiesfunctions,32,WethereforehavesomeunderstandingofCellprocessesProteinadsorptionWoundhealingSuccessfultreatmentofmedicalconditionButlackingunderstandingoftherelationshipbetweentheeventsthatoccuratthesurfaceandthefinalsuccessfuloutcome,33,TheFuture,BiomaterialswillnotfightbiologybutwillintegrateintothebiologicalsystemBiomaterialsscienceversusbiomaterialsengineeringMaterialsandbiologyworkingtogether,34,Self-assembledmaterialsSurfacemodifiedmaterialsforpromotionofcellinteractionsPhotonicmaterialsMaterialswhichmimictheECM,35,ANewDefinitionofBiocompatibility,Biostablematerialswhichpassroutinetoxicologicaltestshealindistinguis