Micro-scaffold-Array-Chip-for-Upgrading-Cell-based

–610LabonaChipPAPERCitethis:LabChip,2014,14,471Received27thSeptember2013,Accepted21stOctober2013DOI:10.1039/c3lc51103k†XiaokangLi,aXinyongZhang,aShanZhao,aJingyuWang,aGangLiubandYananDu*acCell-basedhighthroughputdrugscreeningacceleratesthepaceofdrugdiscoverywhichisroutinelyoperatedonplanarhigh-densitymulti-wellplateswithsophisticatedroboticliquid-dispensingsystemsforcellseedinganddrugadministration.Considerableeffortshavebeenmadetoupgradeinvitrocellularmodelsfrom2Dtoamorebiomimetic3Dconfiguration.Forinstance,inanti-cancerdrugscreening,tumorspheroidsareincreasinglyappliedasagold-standard3Dmodelexhibitingcellularbehaviorsanddrugresponsesdistinguishablefromthe2Dcounterpart.However,translationofspheroidstohighthroughputdrugscreeningischallengingsincepre-formationofspheroidsandsubsequenttranslocationtomulti-wellplatesfordrugtestingareusuallyuncontrollableandtime/reagentconsumingandcelllossisinevitableduringmediumexchangefordrugtesting.Herewepresentanoff-the-shelfmicro-scaffoldarraychipwhichenableshighthroughput3Dcellculture,drugadministrationandquantitativeinsituassaysentirelyonthesamechip.Thesponge-likemicro-scaffoldsfunctionedbothasabsorbentstorealizeparallelauto-loadingofcellsordrugsandasbarrierstopreventcelllossduringmediumexchangeviacentrifugation.Rapidmanualloadingofcellsuspensionsordrugsintothe96isolatedmicro-scaffoldsonthechipwasachievedinthetimescaleofseveralseconds,meanwhilewithtotalmediumconsumptionreducedtotheorderofmicroliters.Proofofconceptdemonstrationofdrugcytotoxicitytestingwasperformedonmultiplecancercellsusingcommonbenchtopequipment,makingitaccessibletomostbiomedicallabswithbasiccellculturesetups.Highercellulardrugresistancewasconstantlyobtainedwiththisplatformcomparedtotheplanarcultures,whichwaspartiallyattributedtothemalignantphenotypeofcancercellsyieldedbyenhancedcell–matrixinteractionsinthemicro-scaffolds.Interestingly,thehighdrugresistanceof3Dculturedcellsinthemicro-scaffoldwasshowntobedensity-independentincontrasttothedensity-dependentdrugresponsefor2Dculturedcells,indicatingintrinsicdifferencesbetweenthetwoculturemodels.Thisplatformisexpectedtofacilitateupgradeofthecurrentcell-basedhighthroughputdrugtestingtothe3Dlevelandbewidelyapplicableacrossvariousdisciplines.1.IntroductionCell-basedhighthroughputscreening(HTS)hasbeenprovedasapowerfultoolforrapididentificationofdrugcandidatesfromlargechemicallibrarieswithdesiredefficacyandsafety,1whichmagnificentlyacceleratesthedrugdiscoveryinabroadrangeofdisciplinesincludinganticancerdrugdiscoveryinoncology.1–7Withtheincreasingmorbidityandmortalityofcancers,8tumorcell-basedHTShasbeenplayingakeyroleinnovelanticancerdrugdiscovery.9–14AnticancerdrugscreeninginHTSisroutinelyoperatedonplanarhigh-densitymulti-wellplateswithsophisticatedandexpensiveroboticliquid-dispensingsystemsforcellseedinganddrugadministrationaswellasmicroscopicfacilitiesforassayreadout,whicharenotavail-ableinnormalbiomedicallaboratories.3,4,6,9–11,13,14Tumorcellsoriginallyresideinahighlyinteractivethree-dimensional(3D)microenvironmentcomposedofcell–cellandcell–matrixinteractionsthatprovidesignalsnecessaryfortumorgrowthandaggressiveness.15–17Theseconditionscannotbereflectedbyconventionalplastic-/glass-based2Dplanarculturesystems.Anincreasingamountofevidencehasprovedthatthe3DtumormicroenvironmentaffectsbothtumorigenesisandtheresponseofcancercellstoaDepartmentofBiomedicalEngineering,SchoolofMedicine,TsinghuaUniversity,Beijing,China.E-mail:[e-mail];Fax:[phone];Tel:[phone]bDepartmentofPharmacologyandPharmaceuticalSciences,SchoolofMedicine,TsinghuaUniversity,Beijing,ChinacCollaborativeInnovationCenterforDiagnosisandTreatmentofInfectiousDiseases,Hangzhou310003,China†Electronicsupplementaryinformation(ESI)available.SeeDOI:10.1039/c3lc51103kLabChip,2014,14,471–481|471Thisjournalis©TheRoyalSocietyofChemistry2014Publishedon21October2013.DownloadedbyWUHANUNIVERSITYOFTECHNOLOGYon17/12/201414:15:26.ViewArticleOnlineViewJournal|ViewIssuechemotherapies.7,18–21Tumorcellsin3Dmicroenvironmentsundergopartialdifferentiationtothemalignancystateandbecomelesssensitivetochemotherapies.18,22,23Besides,receptorsofgrowthfactors(e.g.β-integrin,EGFR)thatplaykeyrolesincancerbiologyareexpresseddifferentlyin3Dculturedcells,18allofwhichindicate3Dcultureformatasabettermodelforinvitrocancerstudy.Recentadvancesin3Dcancercellculturehaveemployedcellularspheroidsasawidelyapplied‘goldstandard’model,whichexhibitcellularbehaviorsanddrugresponsesdistin-guishablefromthe2Dcounterpart.7,19,21,24–27However,thetranslationofthespheroidsfor3Dcell-basedhighthroughputdrugscreeningischallenging.Tumorspheroidsareusuallygeneratedeitherbyhangi