CONICET | Buscador de Institutos y Recursos Humanos

on Iron oxideoxide magnetic magneticnanoparticles nanoparticles (MNP) have havehavebeen beenwidely widelyused in both,both, diagnostic diagnostic and therapy therapy therapyforfor cancercancer cancer cancerdisease researchresearch research research .OneOne of the mostmost mostimportant importantimportantimportantimportantapplications applicationsapplications applications is magnetic magnetic hyperthermiahyperthermia hyperthermia hyperthermia hyperthermia therapy, therapy,therapy,therapy,therapy,in which, which, which,the cells cells arearearekilled by increasing increasing increasing increasingtemperaturetemperature temperature temperaturetemperature temperatureusing MNP as electromagnetic electromagnetic electromagneticelectromagneticelectromagnetic electromagneticto heat heatenergy energyenergy transductors transductors transductors transductors.ForFor this, this,MNP properties properties propertiesmust mustbe optimized optimized optimized in order order to obtain obtainobtain ahigher heat heatquantityquantity quantity using usinglow lowMNP doses doses [1].In this work,work, Small Small Angle X-Ray RayScattering ScatteringScatteringScatteringScattering is used to obtain obtainobtain morphologic morphologic and structuralstructural structuralstructural structural information informationinformation information from from aqueous aqueous colloidalcolloidal colloidalcolloidal suspension suspension of MNP synthesizedsynthesized synthesized synthesized followingfollowing following the chemical chemical chemicalchemicalco -precipitation precipitation precipitation precipitationprecipitation precipitationmethod method[2].The synthesissynthesis synthesis temperaturetemperature temperaturetemperaturetemperature temperaturewaswas fixed fixed in 25 ,40 ,60 and 80 oCin order order to achieve achievedifferent differentdifferentdifferent different differentparticle particle size sizedistributions distributions .The MNP werewere weresuperficially superficially superficially superficiallymodified using citric citric acidacid and dispersed dispersed in waterwaterwaterwater .Asphericalspherical spherical spherical formform factorfactor factor and andamass -fractal fractal fractal structurestructure structure structurefactorfactor factor [3]werewere wereneeded needed in order order to fit all the SAXSSAXS SAXSpatterns patternspatternspatterns .ResultsResults showedshowed showedshowed that thatthe lower lowerlower synthesissynthesis synthesis synthesistemperaturetemperature temperature temperaturetemperature temperaturethe higher particle size sizesize(radius (radius between between between between2.7andand 4.1nm) and the higher higher heat heatdissipation dissipation dissipation at radiofrequencyradiofrequency radiofrequency radiofrequencyradiofrequency fields of 100 kHz varyingvarying varying amplitudeamplitude amplitude .Apartial aggregation aggregation aggregation aggregationaggregationaggregation of nanoparticles nanoparticles werewere werealso determined determineddetermined determined by fitting fitting fitting SAXSSAXS SAXSpatterns patternspatternspatterns patterns with with almost almostspherical spherical spherical aggregatesaggregatesaggregates aggregates aggregatesaggregatesaggregates (df≈ 2.9)with sizes sizessizes around around 20 nm .Better BetterBetter heat heatdissipation dissipation resultsresults werewere wereachieved achieved when the coatingcoating coating werewere werechanged changed changed from from citric citric acid acidto sodium sodium citrate citrate citratecitratecitrateandand poly ethylene ethylene ethylene glycol glycolglycol without significant significant significant significantchange changein the structuralstructural structural structuralstructuralparameters parameters parameters parametersfoundfound with SAXSSAXS SAXS.