IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Designing a SAXS methodology to determinate the UP_TAKE of magnetic nanoparticles in cell cultures
Autor/es:
PAULA ANDREA SOTO; PATRICIA SETTON; DIEGO FERNANDO CORAL; GUILLERMO ARTURO MUÑOZ MEDINA; MARCELA B. FERNÁNDEZ VAN RAAP; JENNY MERA; FRANCISCO HOMERO SANCHEZ
Lugar:
Campìnas
Reunión:
Congreso; 28th Annual user meeting LNLS/CNPEM; 2018
Institución organizadora:
Laboratorio Nacional de Luz Sincrotrón (LNLS)
Resumen:
The incorporation incorporation incorporation incorporation incorporation incorporation of magneticmagnetic magnetic nanoparticles nanoparticles nanoparticles(MNP) in cells cells is atopic topic of increasing increasing increasing interest due to itsits application application application in medicalmedical diagnosis diagnosis diagnosisand therapy therapy therapy .Examples Examples among among amongothers others are aretissue tissue engineering, engineering, cell cell therapy therapy therapy and magneticmagnetic hyperthermia hyperthermia allowing allowingacombination combinationcombination combination combinationwith magneticmagnetic imaging imaging imagingand cell cellcelltacking tacking [1].In -vitro vitroexperiments experimentsexperiments experiments have demonstrated demonstrateddemonstrated demonstrated demonstrated that that MNP are mostlymostly mostly locatedlocated inside inside cells cells compartments compartments compartments compartmentscalled called endosomes endosomes .Regarding Regarding magneticmagnetic hyperthermia, hyperthermia, hyperthermia, how MNP structuring structuring structuring affects affects heating heating efficiency efficiency has been studied studied studiedin ferrofluids ferrofluids ferrofluids ferrofluids [2]and in cell cell cultures cultures[3].Nevertheless, Nevertheless, how these these nanoparticles nanoparticles nanoparticles are arranged arranged inside inside insidecells cells andand whether whetheris possible possible possibleto quantify quantify quantify thethe up -take using usingusing Small Small Angle Angle X-ray Scattering Scattering Scattering(SAXS) (SAXS) are openopen questions questionsquestions questions.In thisthis work, work,we show show how to use useSAXS patterns patternsto quantify quantifyquantify quantify the thecellularcellular cellular up -take and to analyze the theMNP structuring structuring structuring in cells cells .To this end, SAXS SAXSSAXSdata was acquired acquired acquired in MNP aqueous aqueous aqueoussuspensions suspensions suspensions and in B16 (murine (murine (murine (murinemelanomamelanoma melanoma melanomatumor) tumor)tumor) tumor)cell cell labelled with MNP .In order order to analyze size sizeand coating coating effects effects in MNP structuring structuring structuring structuring inside inside insideendosomes, endosomes,endosomes, iron iron oxide oxideoxide core coreMNP, MNP,and coated with two different differentdifferent different surfactants surfactants surfactants surfactants (DMSA and citric acid), acid), acid), acore/shell core/shell structure structure structure structure composed composed composed by iron/iron iron/iron iron/iron iron/ironoxide oxideoxide coated with withsodium sodium citrate, were wereused used .Subsequently, Subsequently, Subsequently, Subsequently, Subsequently,Subsequently,the theup -taketake was determineddetermined determined determined as follows follows follows .SAXS SAXS patterns from colloid colloidwere were measuredmeasured measured at dilutions dilutions dilutions from 0.01 mg Fe /ml /mlto nominal nominalnominal concentration concentration concentration concentration.All these patterns were well well fitted fitted using the spherical spherical spherical sphericalform formformfactorfactor factor and amassmass -fractal fractal fractalstructure structure structure structurefactor factor following following following the monodispersemonodisperse monodisperse monodisperse monodispersemonodisperse approximation approximation approximation .The Thespherical spherical spherical form formformfactor factor contribution contributioncontribution contributioncontribution was wasused to extrapolate extrapolateextrapolateextrapolatethe dΣ /dΩ value at q=0(dΣ (0)/ dΩ ).Alinear linear linearapproximation approximation approximation approximation between between colloid iron ironconcentration concentration concentration concentration ([x][x][x])andand dΣ (0)/ dΩ was determined determined determined and used used to find findthe theiron ironconcentration concentration in cell cell cultures ([x][x][x]in cell cell ).Finally, Finally, Finally,the theup -take waswas calculated calculatedby dividing dividing dividing [x][x][x]in cell cellcellwithwith the thecell cell volumetric volumetric volumetricvolumetric concentration concentration (N).Results Results Results showed showed that that up -taketaketake is aroundaround around around23 andand 54 pg Fe /cell for forthe theused used cells cells suspensions, suspensions, suspensions, suspensions, suspensions,these these values values are in agreement agreement with previous previous previous reported reported values values obtained obtained using using usingdc magnetometrymagnetometry magnetometrymagnetometry [3]