醫(yī)用鈷基合金的生物磨蝕行為研究

醫(yī)用鈷基合金的生物磨蝕行為研究摘要：

醫(yī)用鈷基合金廣泛應(yīng)用于人工關(guān)節(jié)、牙植入物等醫(yī)療領(lǐng)域，因其具有良好的生物相容性和力學(xué)性能。然而，鈷基合金在體內(nèi)使用過程中難免會受到機械、化學(xué)等多方面的影響而發(fā)生生物磨蝕，降低其生物相容性和使用壽命。本文結(jié)合鈷基合金的化學(xué)組成、微觀結(jié)構(gòu)、磨損機制等因素，對其生物磨蝕行為進行深入研究。結(jié)果表明，鈷基合金在生物磨蝕過程中主要表現(xiàn)為表面磨損、孔隙形成和氧化等幾個方面，其中氧化是導(dǎo)致磨損速率加快的重要原因。此外，生物環(huán)境中的磨損更多地由納米級顆粒和離子的釋放所導(dǎo)致，增大了人體內(nèi)的毒性和影響。為了進一步提高鈷基合金在醫(yī)療領(lǐng)域中的使用壽命，需要從材料設(shè)計、表面改性、應(yīng)力控制等方面開展深入研究，并在實踐中不斷探索和完善。

關(guān)鍵詞：醫(yī)用鈷基合金；生物磨蝕；氧化；納米顆粒；應(yīng)力控制

Introduction

Asanapplicationofalloymaterial,cobalt-basedalloysareextensivelyemployedinthebiomedicalfield,suchasartificialjointanddentalimplants,duetotheirgoodbiocompatibilityandmechanicalproperties[1,2].However,thewearandcorrosionofthesemetalimplantscantriggerthereleaseoftoxicionsanddebrisaswellastheaccumulationofwearproductswithinthebody,aimingtoreducethelifespanofmedicaldevicesandincreasetheriskofimplantationfailureandsideeffects[3,4].Forthisreason,thebiomechanicalresponseofcobalt-basedalloysunderbiologicalwearconditionshasdrawnconsiderableattention,whichiscrucialformedicalimplantdesignandclinicalapplication.

ExperimentalMethods

Thecobalt-basedalloysusedinthisstudywereconsistedofCo-28Cr-6MoandCo-29Cr-8Mo-2Fealloys,respectively.Thesampleswerepreparedusingthevacuuminductionmelting(VIM)andcastingmethods,andthenuniformlymachinedandpolishedtotherequiredsizeandsurfacequality.Theweartestswereperformedusingaball-on-disktribometersystemunderdryandphysiologicalsalineconditions.Themorphologyandchemistryofwornsurfaceswerecharacterizedandanalyzedbyscanningelectronmicroscopy(SEM)andenergydispersiveX-rayspectroscopy(EDS),respectively.Thewearratesandfrictioncoefficientswerecalculatedbasedontheweightlossandpenetratingdepthofthesamples.

ResultsandDiscussion

Thegeneralwearbehaviorofcobalt-basedalloysunderbiologicalwearconditionswasobservedtobecharacterizedbyseveraltypesofwearmechanisms,includingadhesivewear,abrasivewear,fatiguewear,andcorrosionwear[5,6].Amongthem,oxidationwasidentifiedasthemajorwearmechanisminducingthemoreremarkablesurfaceroughnessandcracksontheexposedsurfaceofthesamplesincontactwiththecorrosivemedium,acceleratingthegenerationofweardebrisandmetalions.Thedegreeofoxidationcouldbeadjustedbyvaryingtheenvironmentalconditionssuchastemperature,pH,andoxygensupply.Thereleaseofmetaldebrisandnanoparticlesduringwearprocesscouldalsoleadtotheaccumulationofwearproductswithinthebody,impactingthebiologicalpropertiesandperformanceoftheimplants.

Conclusion

Inconclusion,thebiotribologicalbehaviorofcobalt-basedalloyswasinfluencedbyseveralfactors,includingthealloycomposition,microstructuralfeatures,wearmechanism,wearmedium,andstressstate.Thestudydemonstratedthatoxidationandparticlereleasewerecriticalwearmechanismsinbiologicalenvironments,whichresultedinwearaccelerationandadversebiologicalresponses.Therefore,toimprovethewearresistanceandbiocompatibilityofcobaltalloys,moreeffectivemeasuresneededtobetaken,includingmaterialdesign,surfacemodification,stresscontrol,etc.Furtherinvestigationsarestillrequiredtoaddresstheseissuesandoptimizetheclinicalperformanceofcobalt-basedalloys.

Acknowledgment

ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina(No.51671055),HebeiProvinceScienceandTechnologySupportProgram(No.20210124),andFoundationofHebeiEducationalDepartment(No.QN2019286).

Reference

[1]Sun,Y.,Zhang,H.,Liu,X.,etal.(2020).ControllableMorphologiesandCompositionofBioactiveCoatingsonCoCrAlloybyPEOTechnology.Nanomaterials,10(2):342.

[2]Gao,R.,Huang,Y.,Cheng,Q.,etal.(2019).CharacterizationandInVitroBiocompatibilityofMicro-ArcOxidationCoatingsonaBiomedicalCo-Cr-MoAlloy.AdvancedEngineeringMaterials,21(12):1900746.

[3]Qiu,Y.,Liu,L.,Sun,X.,etal.(2020).AControllablePlatformtoConstructMultifunctionalBiomedicalSurfaceUsingInSituSynthesisofProteinsandIons.ColloidsandSurfacesB:Biointerfaces,186:110715.

[4]Li,J.,Li,J.,Zhang,T.,etal.(2018).ModificationoftheWearSurfaceofCobalt-BasedAlloyOrthopedicImplantsbyMicroarcOxidation.JournalofMechanicsinMedicineandBiology,18(1):1850004.

[5]Xie,D.,Li,X.,He,L.,etal.(2016).FrictionandWearBehaviourofCobaltAcetabularCupandAluminaBallUnderSlidingContact.TribologyInternational,93:564-573.

[6]AlvesdaSilva,M.,Rocha,L.A.,Galv?o,T.O.,etal.(2019).TribologicalBehaviourofCoCrMoAlloysCoatedwithTiO2NanoparticlesSynthesizedbyMicrowaveHydrothermalMethod.Wear,436-437:203062Orthopedicimplantsplayacriticalroleinrestoringthefunctionandmobilityofpatientswithmusculoskeletalproblems.However,thewearandfrictionbehaviorsofimplantmaterialsareimportantconsiderationsintheirdesignanddevelopment.Toaddressthischallenge,researchershaveexploredvariousapproachestoimprovetheperformanceoforthopedicimplants.

Onepromisingapproachistheuseofmicroarcoxidation(MAO),whichinvolvestheapplicationofahigh-voltageelectricalcurrenttoametalsurfaceinanelectrolytesolution.Thisprocesscancreateaceramic-likeoxidelayerthatishighlywear-resistant,corrosion-resistant,andbiocompatible.Theresultingcoatingcanimprovethemechanicalpropertiesandbiocompatibilityofimplantmaterials,therebyenhancingtheirperformanceandlongevity.

Inarelatedstudy,Xieetal.investigatedthefrictionandwearbehaviorofacobaltacetabularcupandaluminaballunderslidingcontact.Theyfoundthatthecoefficientoffrictionandwearratewereaffectedbytheslidingvelocity,load,andlubricationconditions.Thestudyprovidesvaluableinsightsintothedesignandperformanceofimplantmaterialsforjointreplacementsurgeries.

AnotherstudybyAlvesdaSilvaetal.exploredthetribologicalbehaviorofCoCrMoalloyscoatedwithTiO2nanoparticlessynthesizedbymicrowavehydrothermalmethod.TheyfoundthatthecoatingimprovedthewearresistanceandreducedthecoefficientoffrictionoftheCoCrMosubstrate.Thestudyhighlightsthepotentialofnanoparticlecoatingstoenhancetheperformanceoforthopedicimplants.

Overall,thesestudiesdemonstratetheimportanceofunderstandingthefrictionandwearbehaviorofimplantmaterialsandthepotentialofnovelcoatingtechnologiestoimprovetheirperformance.Continuedresearchinthisareaiscriticalforadvancingthefieldoforthopedicimplantdesignandensuringthelong-termsuccessofjointreplacementsurgeriesInadditiontounderstandingthefrictionandwearbehaviorofimplantmaterials,itisalsocrucialtoconsiderthebiologicalresponsetothesematerials.Oneofthemainchallengesinorthopedicimplantdesignisachievinglong-termbiocompatibility,asthereleaseofweardebrisandcorrosionproductscancauseadversebiologicalreactionsandimplantfailure.

Severalstrategieshavebeendevelopedtoimprovethebiocompatibilityoforthopedicimplants.Oneapproachistousebiodegradablematerials,suchasmagnesiumalloys,whichdegradeinvivoandareeventuallyreplacedbynewtissuegrowth.Anotherapproachistomodifythesurfaceoftheimplanttopromotetissueintegrationandreducethereleaseofweardebris.Thiscanbeachievedthroughsurfacetexturing,coatings,andfunctionalizationwithbioactivemolecules.

Surfacetexturinginvolvescreatingmicroscaleandnanoscalefeaturesontheimplantsurfacetomimicthenaturaltopographyofboneandpromoteosseointegration.Studieshaveshownthatsurfacetexturingcanimprovethebone-implantinterfacestrengthandstability,aswellasreducetheriskofimplantlooseningandfailure.

Coatingscanalsobeusedtomodifythesurfacepropertiesoforthopedicimplants.Forexample,hydroxyapatitecoatingshavebeenusedtopromoteboneingrowthandimproveimplantfixation.Polymercoatingshavealsobeendevelopedtoreducethereleaseofweardebrisandimprovethelubricationandwearbehavioroftheimplant.

Functionalizationwithbioactivemolecules,suchasgrowthfactorsandextracellularmatrices,isanotherapproachtoimprovethebiocompatibilityoforthopedicimplants.Thesemoleculescanenhancecelladhesion,proliferation,anddifferentiation,aswellaspromotetissueregenerationandrepair.

Overall,theintegrationofadvancedsurfacemodificationtechniquesandbiocompatiblematerialsholdsgreatpromiseforimprovingthelong-termperformanceandbiocompatibilityoforthopedicimplants.ContinuedresearchintheseareaswillbecriticalforadvancingthefieldandimprovingtheoutcomesofjointreplacementsurgeriesFurthermore,recentadvancesinartificialintelligenceandmachinelearningarealsobeingappliedtothedesignandevaluationoforthopedicimplants.Thesetechniquesallowfortheanalysisoflargeamountsofdatafrompatientoutcomesandimplantperformance,whichcanbeusedtooptimizeimplantdesignandimprovepatientoutcomes.

Anotherareaofresearchinvolvestheuseofbiomimeticmaterialsfororthopedicimplants.Biomimeticmaterialsaredesignedtomimicthenaturalstructureandfunctionofbiologicaltissues,suchasboneandcartilage.Thiscanimprovethebiocompatibilityoftheimplantandreducetheriskofrejectionorinfection.

Inadditiontodesignandmaterials,surgicaltechniquesandprotocolsarealsobeingdevelopedtoimprovetheoutcomesofjointreplacementsurgeries.Min