Figure 2: Cellular internalization of SPIONs. (a-f) Photomicrographs showing the morphology of ADSCs incubated with SPIONs at concentrations of 0, 1, 10, 20, 50, and 100 μg ml−1. Scale bars = 20 μm. (g and h) Bar graph showing quantification of cell proliferation and viability at the above SPION concentrations by an MTT assay and trypan blue staining, respectively. (i) Bar graph showing quantification of iron uptake by cells at each of the abovementioned SPION concentrations by atomic absorption spectroscopic measurement. SPION: superparamagnetic iron oxide nanoparticle.