Triple-modal imaging of stem-cells labeled with multimodal nanoparticles, applied in a stroke model

Figure 6 Quantification of multimodal nanoparticles-IR750 internalized by human bone marrow mesenchymal stem cells_Luc using magnetic resonance imaging, inductively coupled plasma-mass spectrometry and near-infrared fluorescence images in vitro. For quantification via MRI, (A) the r₂ values were determined from the intensity signal of MNP-IR750 at different concentrations as a function of TEs (I-II); B: the T2 values of hBM-MSC_Luc labeled with MNP-IR750 at different concentrations were determined based on the adjustment of the MRI signal exponential decay curves obtained for the MRI images of ROIs (III-IV); C: the MNP-IR750 load and number internalized per cell as a function of different labeling concentrations were determined via MRI, and these values were adjusted based on an exponential curve, following equation 3 and the parameters determined for this equation; D: the MNP-IR750 load and number internalized per cell as a function of different labeling concentrations were determined via ICP-MS (V) from the calibration curve generated using known MNP-IR750 concentrations, and the values determined via ICP-MS quantification were adjusted based on an exponential curve, following equation 3 and the parameters determined for this equation; E: the MNP-IR750 load and number internalized per cell as a function of different labeling concentrations were determined via NIRF imaging (VI) from the calibration curve generated using known MNP-IR750 concentrations, and the values determined via NIRF quantification were adjusted with an exponential curve, following equation 3 and the parameters determined for this equation; and F: the correlation of the MNP-IR750 load internalized by hBM-MSC_Luc was compared between ICP-MS and NIRF (blue dots), ICP-MS and MRI (green dots), NIRF and MRI (pink dots). hBM-MSC: Human bone marrow mesenchymal stem cells; MNP: Multimodal nanoparticles; ICP-MS: Inductively coupled plasma-mass spectrometry; MRI: Magnetic resonance imaging; NIRF: Near-infrared fluorescence; BLI: Bioluminescent images.