Multifunctional nanocarrier as a potential micro-RNA delivery vehicle for neuroblastoma treatment

Abstract Neuroblastoma accounts for about 6% of all cancers in children, with a 5–year survival rate of only 20–25%. The increased expressin of MYCN is associated with poor prognosis in patients with neuroblastoma. MicroRNA–34 (miR–34) may serve as a potential target for cancer treatment, owing to its function as an oncogene and tumor suppressor. In this study, positively charged magnetic nanocarriers comprising cross-linked polyethylenimine (PEI)–tripolyphosphate (TPP)–coated iron oxide nanoparticles (IONPs) were developed using co-precipitation method. These nanocarriers were capable of penetrating the cell wall and used for the delivery of miRNA–34a into the cells. The diffraction peak of synthesized magnetic nanocarriers at 2 θ  = 35.44° corresponded to that of magnetite (Fe 3 O 4 ) (311), consistent with Joint Committee on Powder Diffraction Standards (JCPDS) database. The characteristic peaks at 3380, 1620, 2900, and 2840/cm corresponded to those of NH and − CH 2 − groups, indicating the successful coating of PEI. In addition, the small angle neutron scattering (SANS) spectra showed that the alternative magnetic field (AMF) triggered core heat generation, which softened the shells. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed the nontoxicity of these nanocarriers to BE–2–M17 cells. The expression of miR-34a was raised and the expression of MYCN, the target of miR-34a, was significantly suppressed.