Magneticresonanceimaging(MRI)isthemostfrequentlyusedtechniqueforserial
invivocelltrackingapplicationsduetohighresolutionofsofttissues,whichmakesitespeciallyusefulforimagingofthebrain,muscles,ortheheart.¹Inordertoimprovedetect
ABIlityoftransplantedcellsandproduceastrongcontrastagainstsurroundingtissue,intracellularlabelingofcellswithironoxideparticlesbeforetransplantationhasbeendescribed.²FeraTrackDirectContrastParticlesareSPIOnanoparticlesspecificallyformulatedfordirectuptakefromcellculturemediumwithouttheneedoftransfectionreagent.UptakeofFeraTrackDirectContrastParticleswasprovenbyPrussianBluestaining,MRI,andelectronmicroscopy.Biocompatibilitywasassuredbycellexpansionanddifferentiationassaysofintracellularlylabeledcells.Oncewithincells,SPIOscaninducedecreasedsignalintensityonT1,T2,andT2*-weightedimages.³