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

Figure 3

Comparison of different types of nanoparticle-based xenon biosensors classified as synthetic and biogenic host systems. The synthetic Xe hosts are categorized into macrocyclic-based nanocarriers (e.g., cryptophanes and cucurbit[n]urils) and non-macrocyclic-based nanocarriers (e.g., liposomes, nano- and microemulsions, etc.), respectively. The biogenic Xe hosts are typically delineated based on the cellular source from which they are engineered (e.g., bacterial spores and bacterial gas vesicles) or the scaffold platforms which they represent (e.g., MS2 capsids and M13 bacteriophage (adapted with permission from Magn. Reson. Med. 69(5): 1245–1252; copyright (2012) Wiley Periodicals, Inc. (bacteriophage) and from Bioconj. Chem. 27(8): 1796–1801; copyright (2016) American Chemical Society (MS2 viral capsids)) for installing multiple moieties that enable multivalent surface functionalization.