Fig. 3

Cytotoxicity and uptake activity of FeNP/CpG particles in vitro. a MTT assay. We detected the viability of 293T, 4T1, and C26 cells after treatment with various concentrations of FeNP particles for 24 h or 72 h. There was no significant difference in cell viability at any dose of FeNPs. b, c The detection of FeNP/CpG uptake in BMDCs. BMDCs prepared after GM-CSF treatment for 7 days were transfected with CpG-FITC or FeNP-delivered CpG-FITC for 1 or 3 h before being intensively washed, fixed, and labeled with DAPI. Images were captured by laser scanning confocal microscopy (LSCM). Compared with that of free FITC-labeled CpG, the FeNP/CpG with enhanced fluorescence intensity (b) and transfection efficiency were statistically significant (c). These data were representative of three independent experiments, the mean ± standard error; *P < 0.05, *P < 0.01, and ***P < 0.001 vs the untreated group