Süperparamanyetik demir oksit nanoparçacıklarının poliakrilik asitli ortamda kontrollü sentezi

Superparamagnetic iron oxide nanoparticles (SPIO) have been widely studied for a varietyof biomedical applications such as magnetic resonance imaging (MRI), drug and genedelivery, hyperthermia and magnetic separation. Each application requires a specific size andsurface chemistry in addition to stability. Therefore, controlling particle size and sizedistribution, providing functional surfaces and preventing particle aggregation are the keyissues in this field.Coating magnetic cores with polymeric materials to control particle size is one of thecommonly used methods in recent years. In this project, poly (acrylic acid) sodium salt isused as a polymeric stabilizer. Poly (acrylic acid)-stabilized superparamagnetic iron oxidenanoparticles were synthesized by treating iron salts with ammonium hydroxide in water inthe presence of PAA. Major goal of this research is to control particle size and stabilitythrough the control of reaction variables. Primarily, the influence of reaction variables,namely, iron concentration, reactive (COOH)/iron mole ratio, base (NH4OH) amount andpolymer molecular weight, on hydrodynamic size, stability and magnetic nature of theparticles was investigated. In order to design best set of experiments and correlate the resultsto variables, statistical programs Design Expert 7.0 and Minitab14 were used. Through theuse of deducted mathematical equation relating effective factors to the size, we achievedstable aqueous SPIOs with controlled size both in the small and ultrasmall size regime. Inaddition, the choice of PAA as the coating material provided functional groups on the surfacefor attachment of desired molecules and pH responsive nature to the SPIOs.Stability and small sizes of the SPIOs provide a potential for the achievement of moleculartargeting and contrast enhancement for MRI. Another goal of this project is to test thesuitability of these particles for in vivo applications such as targeted and non-targetedimaging and therapy. For this purpose, in vitro cell-studies and MRI imaging were carriedout with the prepared PAA-coated iron oxide nanoparticles with different hydrodynamicsizes (30, 70, 110nm). HeLa and MCF-7 cancer cells were incubated with our samples andcell viabilities were measured by MTT assay. Preliminary results indicate non-toxic behaviorof the particles to the cells. MRI investigation indicated potential for contrast enhancement.