生物材料 Biomaterials

Biomaterials,Biomaterials,Non-viablematerialusedinamedicaldeviceintendedtointeractwithbiologicalsystemsMaterialintendedtointeractwithbiologicalsystems,BiomaterialsScience,PhysicalandbiologicalstudyofmaterialsandtheirinteractionwiththebiologicalenvironmentSynthesisOptimizationTestingBiologyofhost-materialinteractions,Ratner(1993)characterizedbodyresponsetothesematerialsas“blah”NonspecificSluggishkineticsBroadspectrumofactiveprocessesoccurringProteins200+tochoosefromCells(neutrophils,macrophages,platelets)welladaptedtorespondtotheseproteins,Whatweget,Whatwereallywant,DevelopmentofengineeredsurfacesthatelicitrapidandhighlyprecisereactionswithcellsandproteinsTailoredtospecificapplicationResistancetobloodclottingResistancetobacterialinfectionNormaluncomplicatedhealing,BiomaterialsHistory,“Herosurgeons”RidleyandIOLsHipandkneeprosthesesCanadianconnectionKidneydialysisBreastimplantsVasculargraftsStents,TheTerylene,Orlonornylonclothisboughtfromadrapersshopandcutwithpinkingshearstotherequiredshape.Itisthensewnwiththreadofsimilarmaterialintoatubeandsterilizedbyautoclavingbeforeuse.,TheCurrentStateofAffairs,MedicaldevicesareregulatedbytheFDASomedevicesaregrandfatheredbasedonbeingavailablepriortothelegislationintroductionClassifiedbasedonsafetyandpotentialimpacttohumanhealth,MaterialsCommonlyUsedinBiomaterialsApplications,SyntheticPolymersHydrogelsPolyurethanesSiliconebasedmaterialsTeflonDacronPoly(ethyleneoxide)DegradablematerialsNaturalPolymersandOtherNaturalMaterials,MetalsCeramics,glassesandglass-ceramicsPyroliticCarbonComposite,MaterialsandMedicalUses,TheBiomaterialsScientist:AJackofAllTrades,ComputationalchemistryMolecularbiologySurfacephysics/chemistryNanofabricationMaterialsscience,MaterialsProperties,BulkSurface,MechanicalPropertiesofMaterials,ElasticBehaviourofMaterials,Solidmaterialsubjectedtotensileforcewillextendinthedirectionoftractionbyanamountproportionaltotheload,StressandStrain,ExtensionforagivenloadvarieswithgeometryandcompositionNormalizationofloadanddeformationtoallowcomparisonofdifferentmaterialsNormalizedload(force/area)isstress(s),normalizeddeformationisstrain(e)Stressstraincurveisgeneratedfromthisdata,TypicalStressStrainCurve,OtherProperties,TensionandcompressionAreasupportingtheloadisperpendiculartotheloadingdirection,changeinlengthisparalleltooriginallengthShearAppliedloadisparalleltotheareasupportingit,TensileandShearModulus,MechanicalTesting,OtherBulkProperties,PorosityPermeability,SurfaceProperties,Concernedwithfunction(relatedtodesign),durability(relatedtobulkproperties)andbiocompatibility(relatedtosurfaceproperties),Biocompatibility,OverusedtermDefinedasTheabilityofamaterialtoperformwithanappropriatehostresponseinaspecificapplicationTheexploitationbymaterialsoftheproteinsandcellsofthebodytomeetaspecificperformancerequirement,SurfacepropertiesdirectthebiologicalresponseNottoxicologyMechanicalandfunctionaldesign,whilecritical,arenotcentraltobiocompatibility,TheSurface,SurfaceofamaterialisinvariablydifferentfromitsbulkThereisnotmuchtotalmassonasurfaceMicroelectronicsexample:1cm3cubeofTicontainsa100layerofoxide.Thiscanbecomparedtoa5mwidebeachoneachcoastoftheUSSurfacesreadilycontaminatewithcomponentsfromthevapourphase,Figure2:ChangestoPHEMA,Figure3Ratner,So,WeneedtocontrolthesurfaceCreateasurfacethatmimicsthenativebiologyinordertodevelopmaterialsthatare“biocompatible”Needtocharacterizethesurface,Biomimetics,ApproachesthatmimicorreplicatethenaturalfunctionoftissuesareoftenthemostsuccessfulComplexityofnaturaltissuesandorgansisstillfarbeyondtheabilityofscienceforreplicationPrecisefunctionofeveryaspectofthetissueororganisnotknownGeneralconceptshaveemergedfromstudyofstructuralbiologythatprovidedesignstrategiesandguidance,CellsaregeneticallyprogrammedtobuildorgansandtissuesCellsproduceproteins,polysaccharides,glycoproteins,lipidsthatassembleintocompositeextracellularmatricesCellscommunicateviagrowthfactorsandtheirrecruitmentBloodvesselsplayacrucialroleintissuegrowthbyprovidingnutrients,ameansforwasteremovalandasupplyofadditionalcellsNervoussystemisresponsiblefortheintegrationandcontrolofallofthebodiesfunctions,WethereforehavesomeunderstandingofCellprocessesProteinadsorptionWoundhealingSuccessfultreatmentofmedicalconditionButlackingunderstandingoftherelationshipbetweentheeventsthatoccuratthesurfaceandthefinalsuccessfuloutcome,TheFuture,BiomaterialswillnotfightbiologybutwillintegrateintothebiologicalsystemBiomaterialsscienceversusbiomaterialsengineeringMaterialsandbiologyworkingtogether,Self-assembledmaterialsSurfacemodifiedmaterialsforpromotionofcellinteractionsPhotonicmaterialsMaterialswhichmimictheECM,ANewDefinitionofBiocompatibility,Biostablematerialswhichpassroutinetoxicologicaltestshealindistinguisha