壳聚糖I型胶原明胶复合材料的生物相容性及神经修复作用精Word文档格式.docx
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3DepartmentofLiver,GallandPancreas,FirstHospitalofJilinUniversity,Changchun130021,JilinProvince,China
Abstract
Chitosan,collagenIandgelatinweremixedinappropriatequantitiestodevelopanewnerverepairmaterial,withgoodarrangementandstructure,aswellasevenaperturesize.Thecomposite
materialwassterilizedby60Coirradiationfor24hourspriortoimplantationintherightthighofratsfollowingsciaticnervedamage.Resultsshowedthatthematerialwasnontoxictothekidneysandtheliver,anddidnotinduceaninflammatoryresponseinthemuscles.Thecompositematerialenhancedtherecoveryofsciaticnervedamageinrats.Theseexperimentalfindingsindicatethatthecompositematerialoffersgoodbiocompatibilityandhasapositiveeffectoninjurednerverehabilitation.
QingWang☆,M.D.,Professor,China-JapanUnionHospital,JilinUniversity,Changchun
130033,JilinProvince,China
Correspondingauthor:
TiemeiLiu,M.D.,Professor,China-JapanUnionHospital,JilinUniversity,Changchun
130033,JilinProvince,Chinaliutiemei777@
Received:
2012-02-03Accepted:
2012-04-24(N20111015003/WLM)
WangQ,YangXL,RenM,HuYL,ChenQ,XingL,MengCY,LiuTM.Effectofchitosan/typeIcollagen/gelatincompositesin
biocompatibilityandnerverepair.NeuralRegenRes.2012;
doi:
10.3969/j.issn.1673-5374.2012.15.009
KeyWords
chitosan;
collagenI;
gelatin;
biomaterials;
biocompatibility;
nerverepair;
neuralregeneration
cartilage,boneandnervetissuerepair[13].Gelatinisbiodegradable;
however,itisabrittlesubstance,absorbswaterwellandexpands.Thecombinationofgelatinandchitosancancompensateforthedeficienciesineachofthesetwo
compounds.TypeIcollagenisthemostabundantofallthecollagenproteinsthatundergoesnaturaldegradationinthebody.Collagenhasbeenwidelyusedfordrugdeliverysystems,particularlyinburnrepair,asitprovidesasupportingstructureforcells.Collagenmayenhancetheaffinityofchitosantonervecells[14].Publishedpapershaveusedcombinationsofchitosanandgelatin,chitosanand
collagen,orgelatinandcollagenfornerveortissuerepair[15-17].
However,thereiscurrentlynoresearchusingthecombinationofchitosan,gelatinandcollagenIinnerverepair.Thus,theaimofthisstudyistoexplorethe
biocompatibilityandnerverepairpotentialof
INTRODUCTION
Nervedamageiscommonplaceinclinicsduetoaccidentsandinjuries[1].However,maturenervecellshavealimitedcapacityforregeneration.Injurednerveswilltriggervariousfunctionaldisturbancestothebodyiftheyarenotrepairedinatimelymanner.Anidealnerverepairmaterialshouldbe
biocompatible,biodegradableandenhancenervefunctionrehabilitation.
Chitosanisapolysaccharidewithgreatbiocompatibilityandbiodegradabilitythatfacilitatestissueregeneration;
thus,ithasbeenwidelyusedfornerverepair.However,chitosanhasa„crispy‟texturethatmakesitdifficulttosuturetothehosttissues,andtheabsorptionofchitosanisslow,whichaffectsitsefficacyasatreatmentstrategy[2-12].Gelatin,ontheotherhand,isaconstituentofbones,tendons,andconnectivetissuesofanimals,andiswidelyusedinclinicsforskin,
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WangQ,etal./NeuralRegenerationResearch.2012;
achitosan/gelatin/collagenIbiomaterial.
RESULTS
Quantitativeanalysisofexperimentalanimals
Atotalof156ratswereincludedinthisstudy:
96ratswereusedtodeterminethebiocompatibilityofthe
composite,and60ratswereexaminedfornerverepair.Foreachexperiment,theratswereequallydividedintothreegroups:
control(uninjured),injury(injuredonly)andmaterials(injuredandtreatedwithmaterialplacement).Overall,156ratswereinvolvedintheresultsanalysis.
Ultrastructureofchitosan-collagenI-gelatincomposite
Thestructureofthenerverepairmaterialwascylindricalanduniform,withgoodflexibilityandstrongelasticity.Themicrostructureofthetransverse,longitudinalanddiagonalsectionsofthesterilizedmaterialunderascanningelectronicmicroscopeshowedthattheouterstructureofthematerialwasfullyenclosed.Theinnerstructureshowedauniformaperture,withparallel
microtubulestravellinguniformly.Thestructurewasnotaffectedbyporesize,andthetrabecularwalloftheporeshadgoodcontinuity,smoothsurfaces,andnofolds;
theoutersurfacewasimbricated.Thelongitudinalorientationofthemicrotubuleswasindependentofeachotherandinaclosedstate.Therewerenoexchangesforthebridgeconnectingpipesandtheoverallstructurewasirregular,withaninconsistentdiameter.Thetransversesectionsofthematerialwerepredominantlycircular,witharegularshapeanduniformdiameter(Figure1).Theinternalstructureofthematerialwasalsoregular,andtheidealmicrostructurewasconducivetotheregenerationoffiber-orientedgrowth.Thebasicdirectionofthe
microtubuleswasparallelandindependent,withauniformdiameter.Thesestructureshelpedtheanatomicalandfunctionalreconstructionofthenerveafterinjury.
Thebiocompatibilityofchitosan/collagenI/gelatincomposite
Aftersurgery,theactivitylevelfortheratsintheinjuryandmaterialgroupsreducedsignificantly.Thefoot
attachedtotheoperatedlimbwaslame,yettherewasnonotableinflammatoryreactionorself-mutilation.Onday2aftersurgery,theoperatedmusclecicatrizedwell.Atdays3,7,14,21aftersurgery,wenotednoobviouschangestotheembeddedmaterial.
Grossandhistologicalchangesofliver,kidneyandmuscles
Underalightmicroscope,thestructuresoftheliverand
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thekidneysintheratsfromthethreegroupsweresimilar,andnoabnormalchangeswerefound.Intheleft
quadricepsfemorismusclesofratsinthematerialsgroup,numerousinflammatorycellshadinfiltratedaroundthematerialondays3and7.Furthermore,thematerialhadbeensubjectedtophagocytosis,degradedandaforeigngranulomahadformed.Aninflammatoryresponsewasalsoseenintheratsoftheinjurygroup.Ondays14and21,theinflammatoryresponseinthethighmusclesofratsfromthematerialgrouphaddisappeared,buttheforeigngranulomawasstillvisible.Forratsintheinjurygroup,theinflammationhadalsodisappeared,similartothatseenintheratsinthecontrolgroup(Figure2).Therewasnosignificantdifferenceintheorgan:
bodyweightratioinratsamongthesethreegroups(P>
0.05;
Table1).
Figure1Surfacesectionsoftherepairmaterialsunderelectronmicroscopy.
(A)Longitudinalsectionofthematerialshowedan
irregularshapeandaninconsistentdiameter(×
150).
(B)Transversesectionofthematerialshowedthatthe
internalstructurewasregular(×
601).
(C)Transversesectionofthematerialshowedthe
trabecularwallsoftheporeshadgoodcontinuity(×
1201).(D)Transversesectionofthematerialshowedthesurfacewassmooth,withnofolds(×
2403).
Changesofbloodroutineandbiochemicalindicatorsinrats
Therewerenosignificantdifferencesintheperipheralhemoglobinandthelevelofbloodurinenitrogenandurinecreatinefromratsamongthethreegroups(P>
0.05).Ondays3and7afterinjury,thenumberof
peripheralwhitebloodcellsinratsfromthematerialandinjurygroupswassignificantlyhigherthanthatfromthecontrolgroup(P<
0.05).Byday14,thenumberof
peripheralwhitebloodcellsdecreasedtonormallevels.Thechangesinglutamicoxaloacetictransaminase,glutamicpyruvictransaminase,lactatedehydrogenaseandcreatinekinaselevelsfromday3today21areshowninTables2-5.
Liver(×
100)Kidney(×
100)Muscle(×
200)
p
uorglorntoCpuo)rgsylaaidre3(atMpu)osrgyaydru3j(nIpuo)
rgsylaaidre7(atMpu)
osrgyaydru7j(nIpuo)srgyaladi
r4e1(at
M
pu)os
rygaydr
u4j1n(I
uo)rsgy
laadire12at(M
u)osrygaydru1j2n(IFigure2Hematoxylin-eosinstainedsections.Morphologychangesintheliver,kidneysandmusclesweredeterminedusinglightmicroscopy.
Therewerenochangesinliverandkidneysinratsfromthethreegroups.Inthethighmuscles,numerousinflammatorycellshadinfiltratedaftersurgeryinthematerialsandinjurygroups.Bydays14and21,theinflammationhad
disappeared,butforeigngranulomacouldstillbeobserved
inthematerialsgroup.
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Chitosan/collagenI/gelatincompositepromotesthefunctionalrehabilitationofsciaticnerve
Onday45aftersurgery,amuscularelectromyogramshowedthattheinjurednerveinthematerialgroup
recoveredfromthelesionquickerthanthenervesintheinjurygroup(P<
0.01;
Table6).
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DISCUSSION
Nerveinjuryisverycommonclinically.Whennerveinjuryissevereandthenervefunctionislost,thepatientoftenexhibitsaseriesoffunctionaldisturbancesinotherpartsofthebody,whichissometimespuzzlingforclinicians.Assuch,nerverepairhasattractedalotofattention
withinthemedicalprofession.Varioustissueengineeringmethods