Superparamagnetic iron oxide nanoparticles enhance glioma radiosensitivity via inducing cell cycle arrest and apoptosis
Abstract Aim: Superparamagnetic iron oxide nanoparticles (SPIONs) is a widely used biomedical material for imaging and targeting drug delivery. We synthesized SPIONs and tested their effects on the radiosensitization of glioma.Methods: Acetylated 3-aminopropyltrimethoxysilane (APTS)-coated iron oxide nanoparticles (Fe3O4 NPs) were synthesized via a one-step hydrothermal approach and the surface was chemically modified with acetic anhydride to generate surface charge-neutralized NPs. NPs were characterized by TEM and ICP-AES. Radiosensitivity of U87MG glioma cells was evaluated by MTT assay. Cell cycle and apoptosis in glioma cells were examined by flow cytometry. Results: APTS-coated Fe3O4 NPs had a spherical or quasi-spherical shape with average size of 10.5±1.1 nm. NPs had excellent biocompatibility and intracellular uptake of NPs reached the peak 24 hours after treatment. U87 cell viability decreased significantly after treatment with both X-ray and NPs compared to X-ray treatment alone. Compared to X-ray treatment alone, the percentage of cells in G2/M phase (31.83%) significantly increased in APTS-coated Fe3O4 NPs plus X-ray treated group (P<0.05). In addition, the percentage of apoptotic cells was significant higher in APTS-coated Fe3O4 NPs plus X-ray treated group than in X-ray treatment alone group (P<0.05). Conclusion: APTS-coated Fe3O4 NPs achieved excellent biocompatibility and increased radiosensitivity for glioma cells.