Preparation, Characterization And MR Imaging In Vitro Of Poly(D,L-lactide-co-glycolide Acid) Nanoparticles Loaded With Iron Oxide Nanocrystals With Oleic Acid Coating

0bjective: To prepare biodegradable PLGA nanoparticles loaded withiron oxide nanocrystals with oleic acid coating and to explore the effect forMR imaging in vitro.Methods: Magnetic PLGA nanoparticles were prepared by amodified single oil-in-water emulsion method utilizing iron oxidenanocrystals with oleic acid coating and PLGA-COOH. Laser scanningconfocal microscope analysis (LSCM) and transmission electronmicroscopy (TEM) were carried out to examine surface and interiormorphology. The size, distribution and zeta potential were determined byMalvern laser analyzer. X-ray powder diffraction analysis (XRD) was usedto confirm the phase composition. The atomic absorption spectrophotometry(AAS) and thermogravimetry analysis (TG) were carried out to calculate themagnetite entrapment efficiency and magnetite content. Then, magneticPLGA nanoparticles of different Fe concentrations were placed in Eppendoftubes for MR scanning. Results: The samples were brown suspended in deionized water with amean diameter of (292.70±77.07)nm and a polydispersity index of0.009.Zeta potential was (－10.20±4.34)mV. TEM photomicrographs showedthere was lots of iron oxide nanocrystals loaded inside the PLGAnanoparticles. XRD proved the existence of Fe3O4. The magnetiteentrapment efficiency was39.6%and magnetite content was1.036%w/w.MRI showed the reduced signal intensity of different samples with differentFe concentrations in the tubes. The higher Fe concentrations was, the lowersignal intensity became.Conclusion: The developed magnetic PLGA nanoparticles have asmall size and a narrow size distribution. They can effectively decrease T2*signal, therefore can be used as a promising multifunctional MRI contrastagent.