scholarly journals Ultra-stable near-infrared Tm3+-doped upconversion nanoparticles for in vivo wide-field two-photon angiography with a low excitation intensity

2019 ◽  
Vol 12 (03) ◽  
pp. 1950013 ◽  
Author(s):  
Wen Liu ◽  
Runze Chen ◽  
Sailing He
Keyword(s):  
Power Density ◽  
Near Infrared ◽  
Multilayer Coating ◽  
Excitation Power ◽  
Whole Body ◽  
Upconversion Nanoparticles ◽  
Excitation Power Density ◽  
Two Photon ◽  
Coating Method

Two-photon luminescence with near-infrared (NIR) excitation of upconversion nanoparticles (NPs) is of great importance in biological imaging due to deep penetration in high-scattering tissues, low auto-luminescence and good sectioning ability. Unfortunately, common two-photon luminescence is in visible band with an extremely high exciation power density, which limits its application. Here, we synthesized NaYF4:Yb[Formula: see text]Tm@NaYF4 upconversion NPs with strong two-photon NIR emission and a low excitation power density. Furthermore, NaYF4:Yb[Formula: see text]Tm@NaYF4@SiO2@OTMS@F127 NPs with high chemical stability were obtained by a modified multilayer coating method which was applied to upconversion NPs for the first time. In addition, it is shown that the as-prepared hydrophillic upconversion NPs have great biocompatibility and kept stable for 6 hours during in vivo whole-body imaging. The vessels with two-photon luminescence were clear even under an excitation power density as low as 25[Formula: see text]mW[Formula: see text]cm2. Vivid visualizations of capillaries and vessels in a mouse brain were also obtained with low background and high contrast. Because of cheaper instruments and safer power density, the NIR two-photon luminescence of NaYF4:Yb[Formula: see text]Tm@NaYF4 upconversion NPs could promote wider application of two-photon technology. The modified multilayer coating method could be widely used for upconversion NPs to increase the stable time of the in vivo circulation. Our work possesses a great potential for deep imaging and imaging-guided treatment in the future.

The sensitization of laser-induced heat of Er3+ doped Y2O3 nanocrystals by codoped with Mn2+

2015 ◽  
Vol 29 (22) ◽  
pp. 1550158
Author(s):  
Yunfeng Bai ◽  
Minjie Luan ◽  
Linjun Li ◽  
Zhelong He ◽  
Dongyu Li
Keyword(s):  
Power Density ◽  
Thermal Emission ◽  
Energy Levels ◽  
Excitation Power ◽  
Threshold Power ◽  
Excitation Power Density ◽  
Ir Laser ◽  
Order Of Magnitude ◽  
Low Threshold ◽  
Density Threshold

Low threshold power density cw laser-induced heat has been observed in [Formula: see text] and [Formula: see text] codoped [Formula: see text] nanocrystals under excitation by a 980 nm IR laser. Codoped [Formula: see text] remarkably reduces the power density threshold of laser-induced heat compared with [Formula: see text] doped [Formula: see text] nanocrystals. When the excitation power density exceed [Formula: see text], [Formula: see text] codoped [Formula: see text] nanocrystals emit strong blackbody radiation. The thermal emission of [Formula: see text] should originate from the multiphonon relaxation between neighboring energy levels. One additional UC-PL enhancement is observed. The UC-PL intensity can be enhanced by an order of magnitude through high temperature calcination caused by light into heat.

scholarly journals Powering rotary molecular motors with low-intensity near-infrared light

2020 ◽  
Vol 6 (44) ◽  
pp. eabb6165
Author(s):  
Lukas Pfeifer ◽  
Nong V. Hoang ◽  
Maximilian Scherübl ◽  
Maxim S. Pshenichnikov ◽  
Ben L. Feringa
Keyword(s):  
Smart Materials ◽  
Molecular Motors ◽  
Near Infrared ◽  
In Vivo Studies ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Two Photon ◽  
Low Intensity

Light-controlled artificial molecular machines hold tremendous potential to revolutionize molecular sciences as autonomous motion allows the design of smart materials and systems whose properties can respond, adapt, and be modified on command. One long-standing challenge toward future applicability has been the need to develop methods using low-energy, low-intensity, near-infrared light to power these nanomachines. Here, we describe a rotary molecular motor sensitized by a two-photon absorber, which efficiently operates under near-infrared light at intensities and wavelengths compatible with in vivo studies. Time-resolved spectroscopy was used to gain insight into the mechanism of energy transfer to the motor following initial two-photon excitation. Our results offer prospects toward in vitro and in vivo applications of artificial molecular motors.

Excitation-Power-Density Dependent ac Surface Photovoltages in Radiation-Damaged Si Wafer

1984 ◽  
Vol 23 (Part 1, No. 6) ◽  
pp. 778-779 ◽  
Author(s):  
Chusuke Munakata ◽  
Noriaki Honma ◽  
Hajime Hayakawa
Keyword(s):  
Power Density ◽  
Excitation Power ◽  
Excitation Power Density ◽  
Density Dependent ◽  
Si Wafer

Effect of excitation power density on the upconversion luminescence of LaF3:Yb3+, Er3+ nanocrystals

2009 ◽  
Vol 485 (1-2) ◽  
pp. 493-496 ◽  
Author(s):  
Yuqiu Qu ◽  
Xianggui Kong ◽  
Yajuan Sun ◽  
Qinghui Zeng ◽  
Hong Zhang
Keyword(s):  
Power Density ◽  
Upconversion Luminescence ◽  
Excitation Power ◽  
Excitation Power Density

scholarly journals Development of an orally-administrable tumor vasculature-targeting therapeutic using annexin A1-binding D-peptides

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0241157
Author(s):  
Motohiro Nonaka ◽  
Hideaki Mabashi-Asazuma ◽  
Donald L. Jarvis ◽  
Kazuhiko Yamasaki ◽  
Tomoya O. Akama ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Near Infrared ◽  
Tumor Vasculature ◽  
Mirror Image ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Annexin A1 ◽  
N Terminus ◽  
Peptide Phage Display

We previously reported that IF7 peptide, which binds to the annexin A1 (ANXA1) N-terminus, functions as a tumor vasculature-targeted drug delivery vehicle after intravenous injection. To enhance IF7 stability in vivo, we undertook mirror-image peptide phage display using a synthetic D-peptide representing the ANXA1 N-terminus as target. We then identified peptide sequences, synthesized them as D-amino acids, and designated the resulting peptide dTIT7, which we showed bound to the ANXA1 N-terminus. Whole body imaging of mouse brain tumor models injected with near infrared fluorescent IRDye-conjugated dTIT7 showed fluorescent signals in brain and kidney. Furthermore, orally-administered dTIT7/geldanamycin (GA) conjugates suppressed brain tumor growth. Ours is a proof-of-concept experiment showing that ANXA1-binding D-peptide can be developed as an orally-administrable tumor vasculature-targeted therapeutic.

scholarly journals Upconversion Nanoparticles Decorated with Polysialic Acid for Solid Tumors Visualization In Vivo

2021 ◽  
Author(s):  
P. A. Demina ◽  
N. V. Sholina ◽  
R. A. Akasov ◽  
D. A. Khochenkov ◽  
A. V. Nechaev ◽  
...  
Keyword(s):  
Solid Tumors ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Polysialic Acid ◽  
Lymphatic Drainage ◽  
Circulation Time ◽  
High Signal ◽  
Upconversion Nanoparticles ◽  
Nonspecific Protein Adsorption

Abstract Upconversion nanoparticles (UCNPs) are a promising nanoplatform for bioreagent formation for in vivo imaging, which emit UV and blue light under the action of near-infrared radiation, providing deep tissue penetration and maintaining a high signal-to-noise ratio. In the case of solid tumor visualization, the UCNP surface functionalization is required to ensure a long circulation time, biocompatibility, and non-toxicity. The effective UCNP accumulation in the solid tumors is determined by the disturbed architecture of the vascular network and lymphatic drainage. This work demonstrates an approach to the UCNP biofunctionalization with endogenous polysialic acid for in vivo bioreagent formation. Bioreagents possess a low level of nonspecific protein adsorption and macrophage uptake, which allow the prolongation of the circulation time in the bloodstream up to 3 h. This leads to an intense photoluminescent signal in the tumor.

scholarly journals Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2234
Author(s):  
Anbharasi Lakshmanan ◽  
Roman A. Akasov ◽  
Natalya V. Sholina ◽  
Polina A. Demina ◽  
Alla N. Generalova ◽  
...  
Keyword(s):  
Near Infrared ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Laboratory Animals ◽  
In Vitro Toxicity ◽  
Upconversion Nanoparticles ◽  
Lewis Lung Cancer ◽  
Spectral Bands

Formulation of promising anticancer herbal drug curcumin as a nanoscale-sized curcumin (nanocurcumin) improved its delivery to cells and organisms both in vitro and in vivo. We report on coupling nanocurcumin with upconversion nanoparticles (UCNPs) using Poly (lactic-co-glycolic Acid) (PLGA) to endow visualisation in the near-infrared transparency window. Nanocurcumin was prepared by solvent-antisolvent method. NaYF4:Yb,Er (UCNP1) and NaYF4:Yb,Tm (UCNP2) nanoparticles were synthesised by reverse microemulsion method and then functionalized it with PLGA to form UCNP-PLGA nanocarrier followed up by loading with the solvent-antisolvent process synthesized herbal nanocurcumin. The UCNP samples were extensively characterised with XRD, Raman, FTIR, DSC, TGA, UV-VIS-NIR spectrophotometer, Upconversion spectrofluorometer, HRSEM, EDAX and Zeta Potential analyses. UCNP1-PLGA-nanocurcumin exhibited emission at 520, 540, 660 nm and UCNP2-PLGA-nanocurmin showed emission at 480 and 800 nm spectral bands. UCNP-PLGA-nanocurcumin incubated with rat glioblastoma cells demonstrated moderate cytotoxicity, 60–80% cell viability at 0.12–0.02 mg/mL marginally suitable for therapeutic applications. The cytotoxicity of UCNPs evaluated in tumour spheroids models confirmed UCNP-PLGA-nanocurcumin therapeutic potential. As-synthesised curcumin-loaded nanocomplexes were administered in tumour-bearing laboratory animals (Lewis lung cancer model) and showed adequate contrast to enable in vivo and ex vivo study of UCNP-PLGA-nanocurcumin bio distribution in organs, with dominant distribution in the liver and lungs. Our studies demonstrate promise of nanocurcumin-loaded upconversion nanoparticles for theranostics applications.

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