Ultrasound-assisted synthesis of pH-responsive nanovector based on PEG/chitosan coated magnetite nanoparticles for 5-FU delivery

pH-responsive magnetic carriers at the nanoscale are one of the most important agents for the targeted treatment of cancer. In this study, Fe3O4 nanoparticles were prepared by co-precipitation method and functionalized with three types of PEG using ultrasound waves. PEGlated particles were modified with chitosan shell through ultrasound-assisted double emulsion method. The prepared material which was used as a pH responsive carrier for pinpointed 5-FU delivery. The chemico-physical properties of prepared nanoparticles have been investigated. Results demonstrated that pure Fe3O4 had a mean diameter of 20 nm with the regular spherical shape which was increased after modification step depending on the type of PEG. 5-FU loading properties and releasing behaviors studies in different pHs which showed that 5-FU can be efficiently loaded in the Fe3O4@Cs-PEG. Also, in the case of release, the amount of 5-FU released at pH = 5.8 is noticeably higher compared to the released amount at pH = 7.4 in all three samples at any distinct time. For instance at pH = 7.4, 27% of the 5-FU was released from the Fe3O4@Cs-PEG2 during 48 h; as the pH decreases to 5.8, the cumulative amount of 5-FU released enhanced to 52%. The in vitro MTT assay results demonstrated that the cell viability decreases in all synthesized nanoparticles as the pH medium of MCF-7 culture became to 5.8. For example, cell viability of Fe3O4@Cs-sPEG decreased from 44 ± 2% to 36 ± 1.9% at a concentration of 5 (μg/ml) as the pH varied from 7.4 to 5.8.