Growth and accelerated differentiation of mesenchymal stem c

MaterialsChemistry

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Citethis:J.Mater.Chem.B,2014,2,5461

Growthandaccelerateddi erentiationof

mesenchymalstemcellsongrapheneoxide/poly-L-lysinecomposite lms

WeiQi,*WenjingYuan,JingYanandHuaWang*

Anewtypeofcomposite lmsofgrapheneoxide(GO)andpoly-L-lysine(PLL)havebeenfabricatedforuseasbio-sca oldcoatingswithimprovedmechanicalproperties.Themorphology,growthanddi erentiationofmesenchymalstemcells(MSCs)ontheGO/PLLcomposite lmshavebeenexamined.TheresultsdemonstratedthattheGO/PLLcomposite lmscouldnotonlysupportthegrowthofMSCswithahighproliferationrate,butcouldacceleratetheosteogenicdi erentiationofMSCs,showingstrongalkalinephosphatase(ALP)andgeneexpression.Importantly,thehighpre-concentrationcapacityoftheGO/PLL lmsforosteogenicinducerscouldplayakeyroleinacceleratingtheosteogenicdi erentiationofMSCsthroughthestrongnon-covalentbindingandelectrostaticinteractionbetweenthem.Moreover,themildandinexpensivefabricationstrategycouldbeapplicabletobiomacromoleculesincludingchitosan,gelatin,etc.Therefore,suchakindofcomposite lmcouldprovideamultifunctionalandhighlybiocompatiblesca oldcoatingtailoredforpotentialapplicationinstemcellresearch.

Received27thMay2014Accepted24thJune2014DOI:10.1039//MaterialsB

1Introduction

Mesenchymalstemcells(MSCs)isolatedfrombonemarrowhavebeenshowntodi erentiateintoavarietyofcelllineagesinvitro,includingadipocytes,chondrocytes,myocytesandosteo-blasts.ThecombinationofMSCswithsca oldmaterialsprovidesapromisingstrategyforcelltherapyandtissueengi-neering.1–4Somenaturalbiomaterialssuchaspolypeptideshavebeeninvestigatedaspotentialsca oldmaterialsforstemcelltransplantation.Forexample,poly-L-lysine(PLL),withplentifulactiveaminogroupsandpositivesurfacecharges,ismostcommonlyusedinbiomedicaleldssuchasbioactivesurfaces,drugdeliveryandorsoforpromotingcelladhesionandsup-portingcellgrowth.5–7However,mechanicalpropertiesofPLLarenotgoodenoughforsomebiomedicalapplicationssuchasbonetissueengineeringorboneregenerativemedicine.Therefore,itisessentialtodevelopnanocompositesbasedonPLLtoimproveitsmechanicalproperties.Grapheneanditsderivative,grapheneoxide(GO),isanattractivesubstanceasacompositematerial,especiallyaspolymernanocompositesduetoitsextraordinarymechanicalpropertiesincludinghighYoung'smodulus,hardnessandexcellentexibility.Moreover,

asreportedpreviously,theincorporationofGOintoapolymermultilayercouldimprovethelmpropertiessignicantly.8Ontheotherhand,biointerfacescomposedofgrapheneorGOhavebeeninvestigatedforadhesion,proliferationanddi erentia-tionoftheMSCs.9–15Particularly,GO,inwhichthebasalplaneandedgespossessepoxide,carboxyl,andhydroxylgroups,enablesgreaterinteractionswithbiomacromoleculesthroughcovalent,electrostaticandhydrogen-bondingthangraphene.Herein,anewtypeofGO/PLLcompositelmshavebeenbuiltupinthisstudyvialayer-by-layer(LbL)assembly,forgrowth,proliferationanddi erentiationofstemcells(Fig.1).TheLbLassemblytechniquehasbeenwellrecognizedas

a

KeyLaboratoryofLife-OrganicAnalysis,KeyLaboratoryofPharmaceuticalIntermediatesandAnalysisofNaturalMedicine,SchoolofChemistryandChemicalEngineering,QufuNormalUniversity,57JingxuanWestRoad,Qufu,Shandong273165,China.E-mail:qf_qw@;huawangqfnu@;Tel:+865374458208;+865374456306 Electronicsupplementary10.1039/c4tb00856a

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Fig.1

SchematicrepresentationofformationoftheGO/PLL

composite lm.

Thisjournalis©TheRoyalSocietyofChemistry2014J.Mater.Chem.B,2014,2,5461–5467|5461