title: Aggregation-induced near-infrared absorption of squaraine dye in an albumin nanocomplex for photoacoustic tomography in vivo.
abstract: Photoacoustic tomography (PAT) is a newly emerging noninvasive imaging modality that could be further enhanced using near-infrared (NIR)-absorbing materials as contrast agents. To date, the most extensively studied photoacoustic imaging agents are inorganic nanomaterials because organic materials with NIR-absorption capabilities are limited. In this study, a NIR-absorbing nanocomplex composed of a squaraine dye (SQ) and albumin was prepared based on the aggregation-induced NIR absorption of SQ. Through aggregation, the absorption spectrum of SQ was widened from the visible-light region to the NIR region, which facilitated photoacoustic signal generation in the tissue-transparent NIR optical window (700-900 nm). Blood analysis and histology measurements revealed that the nanocomplex can be used for PAT applications in vivo without obvious toxicity to living mice.
authors.affiliation: Nano-organic Photoelectronic Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China.
authors.forename: Fei-Fei
authors.initials: FF
authors.lastname: An
authors.forename: Zi-Jian
authors.initials: ZJ
authors.lastname: Deng
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Zhang
authors.forename: Yin-Long
authors.initials: YL
authors.lastname: Yang
authors.forename: Chang-Hui
authors.initials: CH
authors.lastname: Li
authors.forename: Cai-Jun
authors.initials: CJ
authors.lastname: Zheng
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhang
mesh_terms: D065966:Absorption, Physicochemical; D000818:Animals; D002417:Cattle; D003503:Cyclobutanes; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry*; D006400:Hematocrit; D008099:Liver / Q000378:metabolism; D008807:Mice, Inbred BALB C; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D010636:Phenols; D061088:Photoacoustic Techniques / Q000379:methods*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared; D040521:Subcutaneous Tissue; D014054:Tomography / Q000379:methods*
chemical_list: D003503:Cyclobutanes; D005456:Fluorescent Dyes; D010636:Phenols; C480596:squaraine; D012710:Serum Albumin, Bovine
keywords: albumin; nanocomplex; near-infrared; photoacoustic tomography; red shift; squaraine dye