Effect of Fe3O4 Nanoparticles on Mixed POPC/DPPC Monolayers at Air-Water Interface

Fe3O4nanoparticles (NPs) asacommonly used carrierintargeted drug deliveryarewidelyusedtocarrydrugs for thetreatmentofdiseases.However,themechanismofactionofbetweenFe3O4NPsandbiologicalmembranesisstillunclear.Therefore,thisarticlereportstheinfluenceofhydrophilicandhydrophobicFe3O4NPsonmixed1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) that werestudiedusingtheLangmuir-Blodgett (LB) filmtechniqueandanatomicforcemicroscope (AFM). Fromsurfacepressure-area (π-A)isotherms,wehavecalculatedthecompressionmodulus.TheresultsshowedthathydrophobicFe3O4NPsenlargedtheliquid-expanded (LE) andliquid-condensed (LC) phaseofthemixed POPC/DPPC monolayers.Thecompressibilitymodulusofthemixed POPC/DPP CmonolayerincreasesforhydrophilicFe3O4NPs,buttheoppositehappensforthehydrophobic Fe3O4NPs.Theadsorptionofhydrophobic Fe3O4NPsinmixed POPC/DPPCmonolayerswasmuchmorethanthehydrophilic Fe3O4NPs. TheinteractionofhydrophilicFe3O4NPswiththeheadpolargroupofthemixedlipidsincreasedtheattractionforceamongthemolecules,whiletheinteractionofhydrophobicFe3O4NPs withthetailchainofthemixedlipidsenhancedtherepulsiveforce.ThemorphologyofthemonolayerswasobservedbyAFM for validatingtheinferredresults.ThisstudyisofgreathelpfortheapplicationofFe3O4NP sinbiologicalsystems.