Fig 2. Biocompatibility assessment of SPIONs with or without a ‘hard’ corona of plasma proteins.

Human monocyte-derived macrophages were exposed for 2 h (A, D), 6 h (B, E) or 24 h (C, F) to the indicated doses (μL/mL) of CSNP or CSNP + protein corona (A-C), or to nanomag-D-spio or nanomag-D-spio + protein corona (D-F). Macrophage viability was determined using the MTT assay. Cells were cultured in the absence of FBS to exclude any confounding effects of serum proteins. Results are presented as % mitochondrial function (mean values ± S.D.) from four independent experiments using cells isolated from healthy human donors. Statistical analysis was performed using Tukey post-hoc test following one way ANOVA (**p<0.01, ***p<0.001).