Fig. 7From: Enhanced MRI T 2 Relaxivity in Contrast-Probed Anchor-Free PEGylated Iron Oxide NanoparticlesIn vitro MTS cytotoxicity assays showing the HeLa cell viability in the presence of SPION (a) and PEG-SPION (b) at different concentrations after incubation for 24 h, and in absence and presence of an external static magnetic field. The upper inset in b shows the optical images of PEG-SPION in solution at different concentrationsBack to article page