title: Highly enhanced optical properties of indocyanine green/perfluorocarbon nanoemulsions for efficient lymph node mapping using near-infrared and magnetic resonance imaging.
abstract: The near-infrared (NIR) fluorescence probe has better tissue penetration and lower autofluorescence. Indocyanine green (ICG) is an NIR organic dye for extensive biological application, and it has been clinically approved for human medical imaging and diagnosis. However, application of this dye is limited by its numerous disadvantageous properties in aqueous solution, including its concentration-dependent aggregation, poor aqueous stability in vitro, and low quantum yield. Its use in molecular imaging probes is limited because it loses fluorescence after binding to nonspecific plasma proteins, leading to rapid elimination from the body with a half-life of 2 - 4 min. In this study, the multifunctional perfluorocarbon (PFC)/ICG nanoemulsions were investigated with the aim of overcoming these limitations. The PFC/ICG nanoemulsions as a new type of delivery vehicle for contrast agents have both NIR optical imaging and19F-MR imaging moieties. These nanoemulsions exhibited less aggregation, increased fluorescence intensity, long-term stability, and physicochemical stability against external light and temperature compared to free aqueous ICG. Also, the PFC/ICG bimodal nanoemulsions allow excellent detection of lymph nodes in vivo through NIR optical imaging and19F-MR imaging. This result showed the suitability of the proposed nanoemulsions for non-invasive lymph node mapping as they enable long-time detection of lymph nodes.
authors.affiliation: Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 South Korea.
authors.forename: Pan Kee
authors.initials: PK
authors.lastname: Bae
authors.affiliation: Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 South Korea.
authors.forename: Juyeon
authors.initials: J
authors.lastname: Jung
authors.affiliation: Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 South Korea.
authors.forename: Bong Hyun
authors.initials: BH
authors.lastname: Chung
keywords: 19 F-MR imaging; Indocyanine green; Lymph node mapping; NIR optical imaging; bimodal imaging