Over-1000 nm Near-infrared Fluorescence and SPECT/CT Dual-modal <i>in vivo</i> Imaging Based on Rare-earth Doped Ceramic Nanophosphors

Abstract

In this study, we aimed to develop a dual-modal in vivo imaging based on over-1000 nm near-infrared (OTN-NIR) fluorescence and single photon emission computed tomography (SPECT)/computed tomography (CT). As an OTN-NIR nanophosphor material, Ytterbium and erbium ion co-doped yttrium phosphate nanoparticles (YPO 4 NPs) was synthesized by a hydrothermal synthesis method. Biocompatible poly(ethylene glycol) (PEG)/polycation block copolymer and radioactive 111 In were introduced on the YPO 4 NPs surface In-YPO 4 NPs). The PEG- 111In-YPO 4 NPs showed high dispersion stability in physiological saline and excellent radioactivity in any of PBS and FBS solutions. Furthermore, in vivo OTN-NIR fluorescence and SPECT /CT imaging of live mice was performed. Strong OTN-NIR emission from the blood vessel and organs of live mice were observed. Moreover, SPECT/CT images clearly showed the three dimensional images of the live mice. Therefore, In-YPO 4 NPs is an attractive candidate for the OTN-NIR fluorescence and SPECT/CT dual-modal imaging probe, and the concept can be served as a novel platform for real-time imaging and three dimensional quantitative determinations.

Enhanced Red Upconversion Emission of NaYF4:Yb3+, Er3+, Mn2+ Nanoparticles for Near-infrared-induced Photodynamic Therapy and Fluorescence Imaging

“…These results show that the R/G ratio of MnUNP samples increased with increasing Mn 2+ concentration and that the 50 mol % Mn 2+ -doped MnUNPs had the highest R/G ratio. However, the R/G ratio decreased when the Mn 2+ doping concentration was 54 mol %, probably because the β-phase of NaYF 4 NPs was mixed in the samples, as mentioned above, which would cause relatively weak red emission and thus reduce the R/G ratio. Thus, 50 mol % is the best Mn 2+ doping concentration for synthesizing MnUNPs for PDT.…”

“…In addition, vis-UC emission under NIR excitation can excite vis-light-sensitive photosensitizers and generate ROS in deep tissue. For example, in some studies, 69 the commonly used RED-CNP, NaYF 4 , Er 3+ NP) showed green and red UC emission under 980-nm NIR excitation and was used as a transducer for PDT. In those studies, the photosensitizer, chlorin e6 (Ce6) ( Figure S1 in Supporting Information (SI)) was immobilized on the surface of the NaYF 4 , Mn 2+ NPs (MnUNPs) for the transducer of PDT using a standard solvothermal synthesis method.…”

Fluorescent Polystyrene Latex Nanoparticles for NIR-II <i>in vivo</i> Imaging

“…Therefore, the NIR-II and NIR-III regions are the most ideal wavelength regions for fluorescence bioimaging. In the past decade, our group reported on NIR-II and NIR-III fluorescence imaging based on various probes such as rare-earth doped ceramic nanoparticles (RED-CNPs) [6][7][8][9][10][11], single-walled carbon nanotubes (SWCNTs) [12], and organic dyes [13]. These fluorescent probes showed excellent fluorescence properties, and could be used for successful imaging of deep tissues (10 -20 mm).…”

Over-1000 nm near-infrared fluorescent biodegradable polymer nanoparticles for deep tissue in vivo imaging in the second biological window

“…The OTN-NIR region consists of the 'NIR-II' (the second biological window: 1000-1350 nm) and the 'NIR-III' (the third biological window: 1500-1800 nm) regions, and NIR light in these regions can penetrate the body deeper than the currently used NIR-I (first biological window: 700-900 nm) region. [3][4][5] Various nanomaterials, such as quantum dots, 6 single-wall carbon nanotubes 7 and rareearth-doped ceramic nanoparticles, [8][9][10][11] are well known to demonstrate OTN-NIR emission; many researchers, including our group, have reported successful in vivo fluorescence imaging using these nanomaterials. However, synthesis of these nanoparticles requires high levels of chemical experimental skill and is time consuming.…”