UV-Trained and Metal-Enhanced Fluorescence of Biliverdin and Biliverdin Nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Parinaz Fathi ◽  
Ayman Roslend ◽  
Kritika Mehta ◽  
Parikshit Moitra ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Biomedical Imaging ◽  
Enhanced Fluorescence ◽  
Metal Enhanced Fluorescence

Increasing the fluorescence quantum yield of fluorophores is of great interest for in vitro and in vivo biomedical imaging applications. At the same time, photobleaching and photodegradation resulting from continuous...

scholarly journals FeSe quantum dots for in vivo multiphoton biomedical imaging

2019 ◽  
Vol 5 (12) ◽  
pp. eaay0044 ◽  
Author(s):  
J. Kwon ◽  
S. W. Jun ◽  
S. I. Choi ◽  
X. Mao ◽  
J. Kim ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Yield ◽  
Biomedical Imaging ◽  
Growth Factor Receptor ◽  
Tumor Model ◽  
Excitation Wavelength ◽  
Mcf7 Cells ◽  
Photon Excitation

An immense demand in biomedical imaging is to develop efficient photoluminescent probes with high biocompatibility and quantum yield, as well as multiphoton absorption performance to improve penetration depth and spatial resolution. Here, iron selenide (FeSe) quantum dots (QDs) are reported to meet these criteria. The synthesized QDs exhibit two- and three-photon excitation property at 800- and 1080-nm wavelengths and high quantum yield (ca. 40%), which are suitable for second-window imaging. To verify their biosuitability, poly(ethylene glycol)-conjugated QDs were linked with human epidermal growth factor receptor 2 (HER2) antibodies for in vitro/in vivo two-photon imaging in HER2-overexpressed MCF7 cells and a xenograft breast tumor model in mice. Imaging was successfully carried out at a depth of up to 500 μm from the skin using a nonlinear femtosecond laser at an excitation wavelength of 800 nm. These findings may open up a way to apply biocompatible FeSe QDs to multiphoton cancer imaging.

Changes of Excitation Spectra of in vivo Chlorophyll Fluorescence during Induction of Photosynthesis

1993 ◽  
Vol 48 (1-2) ◽  
pp. 46-51 ◽  
Author(s):  
Wieslaw I. Gruszecki ◽  
Zbigniew Krupa
Keyword(s):  
Energy Transfer ◽  
Chlorophyll Fluorescence ◽  
Quantum Yield ◽  
Dark Adaptation ◽  
Fluorescence Quantum Yield ◽  
Excitation Energy Transfer ◽  
Reaction Centers ◽  
Excitation Spectra ◽  
In Vivo Chlorophyll Fluorescence

Excitation spectra of chlorophyll fluorescence from intact rye leaves were registered at different steps of the induction of photosynthesis after dark adaptation. Analysis of these spectra indicates that at least two processes related to spectroscopic features are responsible for a fluorescence quenching. The first one, active during the first 100 s of illumination, was interpreted to consists in an overall decrease of the fluorescence quantum yield of antenna pigments and chlorophylls, in particular close to the reaction centers. The second type of a fluorescence decrease (between 100 s and 300 s of illumination) was found to be in large extent related to decrease of the rate of an excitation energy transfer between accessory xanthophyll pigments and chlorophylls emitting fluorescence. This latter molecular mechanism is discussed as being related to violaxanthin availability to de-epoxidation in the xanthophyll cycle.

scholarly journals Heavy atom-free semiconducting polymer with high singlet oxygen quantum yield for prostate cancer synergistic phototherapy

2019 ◽  
Vol 3 (6) ◽  
pp. 1123-1127 ◽  
Author(s):  
Jian Shen ◽  
Jianjiao Chen ◽  
Zhen Ke ◽  
Dengfeng Zou ◽  
Liguo Sun ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Heavy Atom ◽  
Semiconducting Polymer ◽  
Prostate Cancer Therapy

Heavy atom free NDNT have a great potential for prostate cancer therapy both in vitro and in vivo.

scholarly journals Motility of bile canaliculi in the living animal: implications for bile flow.

1991 ◽  
Vol 113 (5) ◽  
pp. 1069-1080 ◽  
Author(s):  
N Watanabe ◽  
N Tsukada ◽  
C R Smith ◽  
M J Phillips
Keyword(s):  
Bile Flow ◽  
Cytochalasin B ◽  
Time Lapse ◽  
Sodium Fluorescein ◽  
Branch Points ◽  
Bile Canaliculi ◽  
Enhanced Fluorescence ◽  
Microscopic Techniques

Modern fluorescence microscopic techniques were used to image the bile canalicular system in the intact rat liver, in vivo. By combining the use of sodium fluorescein secretion into bile, with digitally enhanced fluorescence microscopy and time-lapse video, it was possible to capture and record the canalicular motility events that accompany the secretion of bile in life. Active bile canalicular contractions were found predominantly in zone 1 (periportal) hepatocytes of the liver. The contractile movements were repetitive, forceful, and appeared unidirectional moving bile in a direction towards the portal bile ducts. Contractions were not seen in the network of canaliculi on the surface of the liver. Cytochalasin B administration resulted in reduced canalicular motility, progressive dilation of zone 1 canaliculi, and impairment of bile flow. Canalicular dilations invariably involved the branch points of the canalicular network. The findings add substantively to previous in vitro studies using couplets, and suggest that canalicular contractions contribute physiologically to bile flow in the liver.

Multifunctional spherical gold nanocluster aggregate@polyacrylic acid@mesoporous silica nanoparticles for combined cancer dual-modal imaging and chemo-therapy

2015 ◽  
Vol 3 (12) ◽  
pp. 2421-2425 ◽  
Author(s):  
Xiaotong Wu ◽  
Lu Li ◽  
Lingyu Zhang ◽  
Tingting Wang ◽  
Chungang Wang ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Polyacrylic Acid ◽  
Mesoporous Silica Nanoparticles ◽  
Enhanced Fluorescence ◽  
Gold Nanocluster ◽  
Theranostic Agents

Multifunctional nanoparticles with aggregation enhanced fluorescence (AEF) properties were fabricated. The resulting NPs were employed as novel theranostic agents for simultaneous dual-modal imaging and chemo-therapy of liver cancer in vivo and in vitro.

scholarly journals Luminescent gold nanoclusters for bioimaging applications

2020 ◽  
Vol 11 ◽  
pp. 533-546 ◽  
Author(s):  
Nonappa
Keyword(s):  
Quantum Yield ◽  
Gold Nanoclusters ◽  
Size Composition ◽  
New Class ◽  
Thiol Monolayers ◽  
Low Toxicity ◽  
Luminescent Gold Nanoclusters ◽  
Stokes Shifts

Luminescent nanomaterials have emerged as attractive candidates for sensing, catalysis and bioimaging applications in recent years. For practical use in bioimaging, nanomaterials with high photoluminescence, quantum yield, photostability and large Stokes shifts are needed. While offering high photoluminescence and quantum yield, semiconductor quantum dots suffer from toxicity and are susceptible to oxidation. In this context, atomically precise gold nanoclusters protected by thiol monolayers have emerged as a new class of luminescent nanomaterials. Low toxicity, bioavailability, photostability as well as tunable size, composition, and optoelectronic properties make them suitable for bioimaging and biosensing applications. In this review, an overview of the sensing of pathogens, and of in vitro and in vivo bioimaging using luminescent gold nanoclusters along with the limitations with selected examples are discussed.

The Influence of Hydrophilic Decoration on X-ray Excited Luminescence Nanoparticles to Singlet Oxygen Production

NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050092
Author(s):  
Xiaosheng Zhu ◽  
Yi Tian ◽  
Lei Dai ◽  
Qiaofeng Wang ◽  
Mei Shi ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Exchange Reaction ◽  
X Ray ◽  
Good Biocompatibility ◽  
Place Exchange ◽  
High Concentrations ◽  
Excited Luminescence ◽  
Tumor Inhibition Rate

(1) Background: Though X-ray excited photodynamic therapy (X-PDT) breakthrough the bottom neck of PDT application in deep tumor by overcoming light penetration depth limitation, the quantum yield of the hydrophilic X-PDT nanoparticles (NPs) still hampered its further application in vivo. Thus, establishing a proper hydrophilic decoration method which can maximally maintain the quantum yield of X-ray excited luminescent NPs is of urgent demand. (2) Methods: We synthesized NaGdF4: [Formula: see text] (NGF) as X-ray excited luminescent NPs and conducted hydrophilic decoration by two hydrophilic ligands, polyethylene glycol-NH2 (PEG) and cysteamine (Cy) via place exchange reaction, and coupled with photosensitizer (MC540) to form a X-PDT nanosystem. We also conducted experiments in vitro and in vivo to evaluate the efficacy of the X-PDT system. (3) Results: Both PEG and Cy decoration NPs presented excellent emission intensity, which could well excite the coupled photosensitizer MC540 to generate significant X-PDT efficacy under low-dose X-ray radiation. Especially for the NGF-Cy-MC540 treatment group, the cell viability reduced to [Formula: see text]% under 0.3[Formula: see text]Gy radiation and [Formula: see text]% under only 0.1[Formula: see text]Gy radiation, which is the lowest radiation dosage in the literature reports so far. In vivo experiment showed about 36% of tumor inhibition rate under 0.3[Formula: see text]Gy X-ray. Besides, no biotoxicity was observed in NGF groups even in high concentrations, demonstrating good biocompatibility. (4) Conclusions: The hydrophilic decoration method by Cy or PEG via place exchange reaction may pave a brand new way and strategy for X-PDT further clinical application.

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