title: Facile Synthesis of Gold Nanospheres Modified by Positively Charged Mesoporous Silica, Loaded with Near-Infrared Fluorescent Dye, for in Vivo X-ray Computed Tomography and Fluorescence Dual Mode Imaging.
abstract: We developed a simple and efficient method to synthesize a novel probe for both computed tomography (CT) and fluorescence imaging. Gold nanospheres were coated with positively charged mesoporous silica (Au@mSiO2-TTA) using a one-pot method to cohydrolyze quaternary ammonium silane and tetraethyl orthosilicate. Subsequently, IR-783, a negatively charged and water-soluble near-infrared fluorescent dye, was electrostatically adsorbed into the silica shell. Transmission electron microscopy imaging, X-ray powder diffraction, and energy dispersive X-ray spectroscopy indicated that Au@mSiO2-TTA had a clear core-shell structure, was monodisperse, had a large surface area (530 m2/g), and had a uniform pore size (2.2 nm). The mesoporous structure could effectively load fluorescent dye. After loading, the zeta potential of the nanoparticle dropped from 48 mV to 30 mV, and after additional modification with polyvinylpyrrolidone, it further reduced to 6 mV. Probe fluorescence was stable over time, and the probe was an effective CT contrast agent and as a near-infrared fluorescent probe. The half-life of the probe in the blood was 1.5 h, and the probe was mainly distributed in the spleen and liver 4 h after injection. Tissue sections showed that major organs were normal and without visible morphological changes, 6 days post injection, indicating the biocompatibility of the probe.
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Ji-Tao
authors.initials: JT
authors.lastname: Song
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Xiao-Quan
authors.initials: XQ
authors.lastname: Yang
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Xiao-Shuai
authors.initials: XS
authors.lastname: Zhang
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Yan
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Zhao-Yang
authors.initials: ZY
authors.lastname: Wang
authors.affiliation: Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics and Molecular Imaging Key Laboratory, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
authors.forename: Yuan-Di
authors.initials: YD
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002460:Cell Line; D003287:Contrast Media / Q000737:chemistry / Q000493:pharmacokinetics; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006207:Half-Life; D007259:Infrared Rays; D051379:Mice; D008819:Mice, Nude; D054118:Nanospheres / Q000737:chemistry*; D016062:Porosity; D011205:Povidone / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D019265:Spectroscopy, Near-Infrared; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes; D006046:Gold; D012822:Silicon Dioxide; D011205:Povidone
keywords: Au nanoparticle; CT imaging; NIR fluorescence imaging; dual mode imaging; mesoporous silica