简介：Cellaffinityisanimportantfactortobeconcernedwhenbiodegradablepolymericmaterialsareutilizedascellscaffoldintissueengineering.Manystudieshaveprovedthathydrophilicity,surfaceenergy,chargeandroughnessofthematerialsurfacegreatlyinfluencethecellattachmentandcellgrowthonthematerial.
简介：在这研究，(L减水乳酸)(PLLA)一系列monodispersed被戒指洞聚合poly综合与Schiff基础铝催化剂，并且数字一般水准的效果分子的重量(M结晶化和PLLA的融化的行为上的n)被微分扫描热量测定(DSC)和宽角度的X光检查衍射(WAXD)调查。PLLA的全部的结晶化率是M与M-dependent,>18.6kg/mol的n。另外，当PLLA的Mn是18.6kg/mol时，融化的热含量(Hm)显示出最大的价值(87.1J/g)，它是最高报导的价值到现在为止。为水晶形成从的变化的批评温度-到形式，在等温的结晶化增加的晶体与M处理n增加。在再热的过程，high-MnPLLA在主导的融化山峰以前表明了一座小exothermal山峰，相应于水晶转变从-到-form,但是low-MnPLLAdidnt表演水晶转变的山峰。这些不同结晶化和融化的行为与不同Mn。
简介：Recentresearchshowsthattheadditionofchitosanmicrospheres（CMs）topoly（L-lactide）（PLLA）canresultinacompositescaffoldmaterialwithimprovedbiocompatibilityandmechanicalpropertiesfortissueengineeringapplications.However,researchregardingtheinfluenceofCMsonscaffolddegradationisabsentintheliterature.ThispaperpresentsastudyontheinvitrodegradationofscaffoldsmadefromPLLAwithCMs.Inthisstudy,thePLLA/CMsscaffoldswitha25%ratioofCMstoPLLAwereimmersedinphosphate-bufferedsaline（PBS）solutionat37℃for8weeks.Theinvitrodegradationofthescaffoldswasinvestigatedusingmicro-computedtomography（μCT）,weightlossanalysis,Ramanspectroscopy,anddifferentialscanningcalorimetry（DSC）.MicrostructurechangesduringdegradationweremonitoredusingμCT.TheμCTresultswereconsistentwiththeresultsobtainedfromRamanspectraandDSCanalysis,whichreflectedthataddingCMsintoPLLAcandecreasethedegradationratecomparedwithpurePLLAscaffolds.TheresultssuggestthatPLLA/CMsscaffolddegradationcanberegulatedandcontrolledtomeetrequirementsimposedagiventissueengineeringapplication.
简介：(L减水乳酸)(PLLA)Poly，/pristine蛭石nanocomposites被准备由融化掺双轴的extruder，和热、机械的性质的蛭石分散状态的详细信息和蛭石的效果系统地被学习。当装载内容不超过3wt%时，结果证明在矩阵的蛭石的分散相当好。太古的蛭石能显然在nonisothermal结晶化期间改进融化结晶化温度。两结晶化时间跨度和PLLA的spherulitic尺寸由提高PLLA的主要成核在等温的结晶化状况下面与蛭石的增加的数量减少。并且增加的蛭石能也改进张力的模量和PLLA的Izod影响力量。为PLLA上的蛭石的起核心作用的效果的内在的机制被建议是在蛭石和PLLA之间的取向附生的结晶化和特定的相互作用。
简介：Antibacterialpoly(D,L-lactide)(PDLLA)fibrousmembranesweredevelopedviaelectrospinning,followedbysurfacemodificationwhichinvolvedplasmapretreatment,UV-inducedgraftcopolymerizationof4-vinylpyridine(4VP)andquaternizationofthegraftedpyridinegroupswithhexylbromide.ThesuccessofmodificationwithquatemizedpyridiniumgroupsonthePDLLAfibrousmembraneswasascertainedbyX-rayphotoelectronspectroscopy(XPS).TheantibacterialactivitiesofthesemembraneswereassessedagainstGram-positiveStaphylococcusaureus(S.aureus)andGram-negativeEscherichiacoli(E.coli).ThePDLLAfibrousmembranesmodifiedwithquaternizedpyridiniumgroupsshowedantibacterialefficiencyagainstbothbacteriaashighas99.999%.Theresultsdemonstratedthattheantibacterialactivitywasbasedontheinteractionofthepositivechargeofpyridiniumgroupandnegativelychargedcellmembraneofbacteria,resultinginlossofmembranepermeabilityandcellleakage.
简介：稀土元素aryloxides由各种各样的烷基组代替了[行(浆)3]例如甲基，isopropyl和tertbutyl，被用作单个部件催化剂影响L减水乳酸(LLA)的戒指洞聚合。催化活动，聚合特征，聚合动力学和机制被学习。稀土元素aryloxides的催化活动被结构和烷基组的数字在苯基戒指上影响，这被发现。越强壮烷基组的电子捐赠能力，催化活动将是越多higher。代用品组的数字的增加将导致一项更高催化的活动。镧tris(2,4,6-tri-tert-butylphenolate)[La(OTTBP)3]在所有镧aryloxides之中展出最高的活动。根据1H-NMR数据，LLA聚合经由包含减水乳酸的酰氧债券的劈开的协作插入机制继续了，这被建议。关键词戒指洞聚合-L减水乳酸-稀土元素aryloxides这个工作被山西省(号码2006011069)的自然科学基础和山西省(号码2009011059-7)的关键实验室的开的基础支持。
简介：OBJECTIVEPoly-L-lactide(PLLA)isthemainmaterialmakingforbiodegradableosteosynthesis.ButthecommonlyusedprocessesmakethePLLA'sinitialmechanicalpropertiestoolowtosufficientfortheneedforclinicalosteosynthesis.Thenitmustbetodevelopsomespecialprocesstoenhancethemechanicalproperties.
简介：electrospun(lactide-co-glycolide)(PLGA)poly，膜被准备并且过去常执行跟腱的反粘附。在整个实验，膜显示出适当降级率，并且降级媒介的pH价值在约7.4点被维持。同时，在vitro并且在vivo的膜的优秀biocompatibility被实时/死了、组织病理学说的分析证实。同时，膜能显著地减少腱粘附并且有效地支持功能的恢复。令人鼓舞的结果被hematoxylin和曙红(H&E)进一步表明，并且Massons三色的染色，和类型我骨胶原immunohistochemical分析。没有处理，与electrospunPLGA膜对待的模型比那关于粘附预防和织物修理显著地更好，这被结束。就降级和粘附预防功效的结果而言，electrospunPLGA膜将是手术后的腱粘附的预防的一个大候选人。
简介：Thecruxoftissueengineeringistoconstructhighlyporousthree-dimensionalscaffoldwithdesiredcellsonit.Becausethescaffoldservesasbothaphysicalsupportandanadhesivesubstrateforisolatedcellsduringinvitrocultureandsubsequentimplantation,thematerialsforscaffoldshouldbenon-toxicandbiocompatible,highlyporousandprocessableintodevicesofvariousshapes.
简介：Thestructureandkineticsofthecomplexformedbyhyaluronicacid(HA)andpoly(L-lysine)(PLL)werestudiedbytimeresolvedlaserlightscattering,TEM,andAFM.BecauseHAhasahydrophilicbackbone,thecomplexesformedbyHAandPLLaredifferentfromthoseformedbyoppositelychargedpolyelectrolytesbothhavinghydrophobicbackbones.Insteadofformingstrongaggregatesandevenprecipitates,thecomplexinthepresenceofexcessHAisstableinthestudiedtimeperiod.Moreimportantly,thecomplexspontaneouslyformscore-coronastructurebytherearrangementofHAchains.ThecoreiscomposedofcomplexrichofPLLandthecoronaismainlyHA.FurtheranalysisshowsthatthehydrogenbondformedbyHAcreatesabarrierhinderingthefurtherrelaxationofHAchains.Theautomaticformationofcore-coronastructurebyPLL/HAishelpfulnotonlytounderstandtherelaxationofpolyelectrolyteincomplex,butalsotodevelopdrugcarrierswithdesirableproperties.
简介：Oneofthechallengesinthefieldoftissueengineeringisthedevelopmentofbiomaterial/cellinteractions.Forthispurpose,theuseofbiologicalmaterialsintissueengineeringrequirestheapplicationofdifferentchemicalorphysicalproceduresforsurfacemodificationinordertoimprovethecellaffinityofbiomaterials.Wehavestudiedtheeffectsofonechemicaltreatmentandonephysicaltreatment:1-(3-dimethylaminopropyl)-3-ethylcarbodiimide(WSC)andentrapment.
简介：阶段PVDF水晶结构和在先存在的阶段PVDF球粒以内的豌豆的结晶化上的豌豆的效果被光显微镜学OM，红外线的光谱学红外和扫描电子显微镜学SEM调查了。结果证明阶段PVDF球粒由展出高度弄弯的像滚动的形态学的lamellae组成并且在充满豌豆的混合优先地发展。与增加豌豆集中，滚动直径增加和滚动更好与对方被分开。豌豆在interspherulitic区域使第一结晶，transcrystalline层发展。随后，豌豆的transcrystalline层继续在阶段PVDF球粒以内成长，例如在在滚动之间的区域，直到在另外的豌豆transcrystalline层或球粒上侵犯。结晶化动力学结果显示在阶段PVDF的intraspherulitic区域的豌豆晶体的生长率与阶段PVDF的结晶化温度与豌豆，而是否定豌豆的内容显示出积极关联。
简介：Thestarch/D,L-lactidegraftcopolymersweresynthesizedbyreactingD,L-lactidewithcornstarchinN,N-dimethylacetamide(DMAM)inthepresenceoftriethylamine(NEt3)andanhydrouslithiumchloride.TheeffectofreactiontimeandthemolarratioofD,L-lactidetoglucosestructuralunitofstarchonmonomerconversion(C%),graft(G%)andgraftefficiency(GE%)werestudied,TheC%,G%andGE%couldapproach37.3%179.7%and68.0%,respectivelywhenthemolarratioofD,L-lactidetoglucosestructuralunitofstarchis10:1andthegraftcopolymerizationwascarriedoutat80-85℃for4hrundernitrogenatmosphere.TheFouriertransformsinfra-red(FTIR)spectroscopy.differentialscanningcalorimetry(DSC)andX_raydiffraction(XRD)spectroscopywereusedinordertocharacterizethegraftcopolymers.FTIRspectrashowthatabsorptionbandat1740cm^-1confirmedtheformationofesterbond,indicatingthestarch/D,L-lactidegraftcopolymerswereproduced,theDSCcharacteristicresultsshowthemeltingtemperatureofthegraftcopolymerwereelevatedslightlyasthemolarratioofD,L-lactidetoglucosestructuralunitsofstarchincreasedandtheX-raydiffractionspectrashowthesynthesizedgraftcopolymerswereamorphous.Thedegradabilityofgraftcopolymerwastestedwiththeaidofacid,alkaliandmicrobesuchasbacillussubtilisandstaphylococcusaureus.Theresultsofwaterrsistanceshowthegraftcopolymerproducedcanbeusedasacomponentofimpermeablecoatingforcardboard.
简介：Ithasbeenwellknownthatfluorinatedpolyurethanesexhibituniquelylowsurfaceenergy,biocompatibilityandbiostability,thermalandoxidativestabilityandnonstickingbehavior.Consequently,thesepolymershaveattractedconsiderableinterest.However,themechanicalpropertiesoffluorinatedpolyurethanesusuallydeclinewithincreasingfluorinecontents.Theblendingoffluorinatedpolyurethaneswithnormalpolyurethanewascarriedouttoachievebalancedmechanicalandsurfaceproperties.Itwasfoundthatpolyurethanewithgoodmechanicalpropertiesandlowsurfaceenergycanbeobtainedbyaddingasmallamountoffluorinatedpolyurethane.Thefluorinatedsidechainscaneasilymigratetouppermostsurfacesoftheblendsuntillthefluorinelevelatthesurfacebecomesalmostsaturated.Ithasbeenshownfromcontactangle,XPSandAFMmeasurementsthatonlyaslittleas0.34wt%offluorinelevelisenoughtoproduceasurfacesaturatedwithfluorine,andthefluorinelevelattheuppermostsurfaceisonehundredtimeshigherthanthatintheblendbulk.Thefinaloutersurfacestructuresofthepolyurethaneblendwereindependentofthecontentofthefluorinatedpolyurethaneintheblendsduetothesurfacessaturatedbyfluorine.
简介：Anovelsmallband-gapconjugatedpolymer-poly[(3-acetylpyrrole-2,5-diyl)(4-dimethylaminobenzyliene)(3-aeetylpyrrolequinodimethane-2,5-diyl)](PAPDMABE)-anditsprecursorweresynthesizedbyasimplemethodandcharacterizedby1H-NMR,FT-IR,TGAandUV-VIS.ThepolymercanbedissolvedinstrongpolarsolventssuchasDMSO,DMForNMP.Theband-gapenergyofPAPDMABEwasfoundtobe0.95eV.Theconductivityofdopedproductswithiodinefallsintherangeofasemiconductor.``
客服QQ：30444492琼网文【2021】1550-113号
增值电信业务经营许可证：琼B2-20210322
出版物经营许可证：新出发龙华出字第(2021)009号
广播电视节目制作经营许可证：(琼)字第00779号
版权所有 ©2002-2024 期刊网(www.qikanchina.com) 琼ICP备2021005105号
![Degradable properties of laminated composite scaffolds of β-tricalcium phosphate/<b style='color:red'>poly</b>[<b style='color:red'>L</b>-lactic acid]](/image/thesis11 "Degradable properties of laminated composite scaffolds of β-tricalcium phosphate/<b style='color:red'>poly</b>[<b style='color:red'>L</b>-lactic acid]")
