Nanoparticle-Based Contrast Agents for ¹²⁹Xe HyperCEST NMR and MRI Applications

Figure 4

Examples of ¹²⁹Xe HyperCEST applications. (a) Multichannel MRI labeling of cells using CryA-ma and PFOB nanodroplets as different Xe hosts with well-resolved saturation frequency offsets for selective CEST contrast (reprinted with permission from Nano Lett. 14(10): 5721–5726; copyright (2014) American Chemical Society). (b) Switchable ¹²⁹Xe MRI contrast induced by bacterial gas vesicles (GVs) and the corresponding CEST spectrum at different nanoparticle concentrations (adapted with permission from AIChE Journal 64(8): 2927–2933; copyright (2018) American Institute of Chemical Engineers). (c) Sketch of the Xe binding site in β-lactamase (bla) and CEST spectra from the wild-type bla and the I263A mutation with suppressed CEST response (reprinted with permission from Angew. Chem. Int. Ed. 55(31): 8984–8987; copyright (2016) John Wiley & Sons Inc). (d) In vivo demonstration of HyperCEST MRI with CB[6] in a rat study showing contrast in the abdomen and the brain (reprinted under a Creative Commons Attribution 4.0 International License from Scientific Reports 7: 41027 (2017)).