fluorescent imaging
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Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 195
Author(s):  
Maryana Handula ◽  
Marjolein Verhoeven ◽  
Kuo-Ting Chen ◽  
Joost Haeck ◽  
Marion de de Jong ◽  
...  

Nuclear and optical dual-modality probes can be of great assistance in prostate cancer localization, providing the means for both preoperative nuclear imaging and intraoperative surgical guidance. We developed a series of probes based on the backbone of the established GRPR-targeting radiotracer NeoB. The inverse electron demand of the Diels–Alder reaction was used to integrate the sulfo-cyanine 5 dye. Indium-111 radiolabeling, stability studies and a competition binding assay were carried out. Pilot biodistribution and imaging studies were performed in PC-3 tumor-bearing mice, using the best two dual-labeled probes. The dual-modality probes were radiolabeled with a high yield (> 92%), were proven to be hydrophilic and demonstrated high stability in mouse serum (> 94% intact labeled ligand at 4 h). The binding affinity for the GRPR was in the nanomolar range (21.9–118.7 nM). SPECT/CT images at 2 h p.i. clearly visualized the tumor xenograft and biodistribution studies, after scanning confirmed the high tumor uptake (8.47 ± 0.46%ID/g and 6.90 ± 0.81%ID/g for probe [111In]In-12 and [111In]In-15, respectively). Receptor specificity was illustrated with blocking studies, and co-localization of the radioactive and fluorescent signal was verified by ex vivo fluorescent imaging. Although optimal tumor-to-blood and tumor-to-kidney ratios might not yet have been reached due to the prolonged blood circulation, our probes are promising candidates for the preoperative and intraoperative visualization of GRPR-positive prostate cancer.


Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 300
Author(s):  
Wendy Bernhard ◽  
Kris Barreto ◽  
Ayman El-Sayed ◽  
John DeCoteau ◽  
C. Ronald Geyer

Tracking immune responses is complex due to the mixture of cell types, variability in cell populations, and the dynamic environment. Tissue biopsies and blood analysis can identify infiltrating and circulating immune cells; however, due to the dynamic nature of the immune response, these are prone to sampling errors. Non-invasive targeted molecular imaging provides a method to monitor immune response, which has advantages of providing whole-body images, being non-invasive, and allowing longitudinal monitoring. Three non-specific Fc-containing proteins were labeled with near-infrared dye IRDye800CW and used as imaging probes to assess tumor-infiltrating immune cells in FaDu and A-431 xenograft models. We showed that Fc domains localize to tumors and are visible by fluorescent imaging. This tumor localization appears to be based on binding tumor-associated immune cells and some xenografts showed higher fluorescent signals than others. The Fc domain alone bound to different human immune cell types. The Fc domain can be a valuable research tool to study innate immune response.


2022 ◽  
Author(s):  
Maxwell Claef Hakun ◽  
Janet Rossant ◽  
Bin Gu

Spermiogenesis, the post-meiotic stage of sperm development, is critical for normal male fertility. Many genetic defects and environmental assaults that affect spermiogenesis have been shown to be associated with male infertility. In addition, this later stage of spermatogenesis has been proposed to be an ideal target for male contraceptive development. The mouse is a widely used model for studying the mechanisms of spermatogenesis and spermiogenesis. However, due to the complexity and the asynchronous nature of spermatogenesis in adult testis, it is challenging to study molecular processes restricted to this specific developmental stage. It is also challenging to monitor the spermiogenesic activity in live mice, which is critical for screening for fertility-modulating interventions such as contraceptives. Here we reported the development of a Nutm1-T2A- luciferase 2(Luc2)-tandem Tomato(TdTomato) knock-in reporter mouse model that specifically labels post-meiotic spermatids. Homozygous reporter mice are healthy and fully fertile, demonstrating no interference with the normal functions of the Nutm1 gene by the reporter. We demonstrated the visualization of post-meiotic spermatids by fluorescent imaging of the TdTomato reporter in both live and fixed testis tissues. We also demonstrated bioluminescence imaging of Nutm1 expressing cells in live mice. The Nutm1-T2A-Luc2TdTomato reporter mouse can serve as a valuable tool for studying spermiogenesis.


2021 ◽  
Vol 11 (12) ◽  
pp. 203-209
Author(s):  
R. Nikitenko ◽  
K. Vorotyntseva

Over the past years, due to increase of detection of patients with early-stage stomach cancer and colorectal cancer, and improvement of survival rate, the efforts have been made to gradually develop the concept of sentinel lymph nodes detection in order to improve postoperative quality of life. The article presents the review of the literature on the feasibility of sentinel lymph nodes intraoperative diagnosis the choice of surgical treatment of patients with tumors of the stomach and colon. Analytical work demonstrates that the real time intraoperative visualization of lymph sineses using fluorescent imaging of indocyanine green during laparoscopic surgery for stomach or colorectal cancer is possible and it is a useful method of the lymph nodes mapping, therefore it can lead to intraoperative changes at lymphadenectomy as well as to reduce the surgical injury. It indicates the need in further research and improvement of approach.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rixin Chen ◽  
Dan Qiao ◽  
Peng Wang ◽  
Lingjun Li ◽  
Yangheng Zhang ◽  
...  

Fusobacterium nucleatum is a typical periodontal opportunistic pathogen that contributes to inflammatory diseases at oral or extra-oral sites. The emergence of antibiotics resistance calls for a substitute therapeutic strategy to control bacterial infections effectively. In addition, macrophage is an essential part of host defense against microorganism invasion in vivo. Herein, we synthesized gold nanoclusters (AuNCs) as potent antibacterial material to kill F. nucleatum through bactericidal behavior and pro-phagocytic activity. Firstly, we evaluated the bactericidal effect of AuNCs on F. nucleatum by the means of plate counting, growth curve measurement, bacterial viability analysis, and live/dead fluorescent imaging. Morphological changes and the intracellular reactive oxygen species levels of bacteria were further analyzed to explore the possible mechanisms. Additionally, the impact of AuNCs on the ability of macrophages to uptake bacteria under normal and inflammatory circumstance was also evaluated by fluorescent imaging. We found that AuNCs exhibited superior antibacterial performance on F. nucleatum in vitro by a combination of membrane disruption and oxidative stress. Furthermore, in the presence of AuNCs, macrophages displayed enhanced phagocytosis against F. nucleatum without inducing any significant cytotoxicity. Therefore, AuNCs are providing a new platform for the prevention and treatment of F. nucleatum-associated diseases.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shun Tamaki ◽  
Ryosuke Sato ◽  
Yuki Koshitsuka ◽  
Masashi Asahina ◽  
Yutaka Kodama ◽  
...  

Carotenoids are photosynthetic pigments and hydrophobic antioxidants that are necessary for the survival of photosynthetic organisms, including the microalga Euglena gracilis. In the present study, we identified an uncharacterized gene encoding the E. gracilis β-carotene synthetic enzyme lycopene cyclase (EgLCY) and discovered a relationship between EgLCY-mediated carotenoid synthesis and the reactive oxygen species (ROS) scavenging system ascorbate-glutathione cycle. The EgLCY cDNA sequence was obtained via homology searching E. gracilis transcriptome data. An enzyme assay using Escherichia coli demonstrated that EgLCY converts lycopene to β-carotene. E. gracilis treated with EgLCY double-stranded RNA (dsRNA) produced colorless cells with hypertrophic appearance, inhibited growth, and marked decrease in carotenoid and chlorophyll content, suggesting that EgLCY is essential for the synthesis of β-carotene and downstream carotenoids, which are abundant and physiologically functional. In EgLCY dsRNA-treated cells, the ascorbate-glutathione cycle, composed of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDAR), and glutathione reductase (GR), was unusually modulated; APX and GR activities significantly decreased, whereas DHAR and MDAR activities increased. Ascorbate content was significantly increased and glutathione content significantly decreased in EgLCY dsRNA-treated cells and was correlated with their recycling enzyme activities. Fluorescent imaging demonstrated that EgLCY dsRNA-treated cells accumulated higher levels of H2O2 compared to wild-type cells. Taken together, this study revealed that EgLCY-mediated synthesis of β-carotene and downstream carotenoid species upregulates APX activity and increases glutathione pool size for H2O2 scavenging. Our study suggests a possible relationship between carotenoid synthesis and the ascorbate-glutathione cycle for ROS scavenging in E. gracilis.


2021 ◽  
Vol 21 (12) ◽  
pp. 6101-6110
Author(s):  
Dong Sun ◽  
Shu-Jun Li ◽  
Chun-Feng Wang ◽  
Tian-Tian Liu ◽  
Guang-Yue Bai ◽  
...  

Innovative nitrogen and boron co-doped carbon dots are hydrothermally produced using fructose, urea, and boric acid as precursors. The synthesized carbon dots possess a uniform morphology, and exhibit excellent fluorescence stability, tunable luminescence property, strong resistance to photobleaching, low-toxicity, and excellent biocompatibility. It is also found more dopant urea is conducive to the formation of the carbon dots with more B–N bonds, and shorter wavelength of fluorescence emission. Meanwhile, the synthesized carbon dots are well utilized as a photoluminescent probe for facile Hg2+ determination and fluorescent imaging reagent in cells.


2021 ◽  
Vol 21 (12) ◽  
pp. 5965-5971
Author(s):  
Xiaofang Song ◽  
Lifo Ruan ◽  
Tianyu Zheng ◽  
Jun Wei ◽  
Jiayu Zhang ◽  
...  

Facile preparation of a tumoral-stimuli-activated theranostic nanoparticle with simple constituents remains a challenge for tumor theranostic nanosystems. Herein we design a simple reductionresponsive turn-on theranostic nanoparticle for achieving fluorescent imaging and phototherapy combination. The theranostic nanoparticle is prepared by a simple one-step dialysis method of reduction active amphiphilic hyperbranched poly(β-amidoamines) and a near-infrared (NIR) dye indocyanine green (ICG). The fluorescence of ICG is quenched by the aggregation-caused quenching (ACQ) effect. The fluorescent intensity of free ICG at 816 nm was ∼40 times as high as that of particulate ICG. After reductive nanoparticles incubated with dithiothreitol (DTT), the size of the nanoparticles increased from 160 nm to 610 nm by Dynamic light scattering (DLS). As nanoparticles were internalized by cancer cells, the disulfide bonds would be cleaved by intracellular reduction agents like glutathione (GSH), leading to the release of entrapped ICG. The released ICG regained its fluorescence for self-monitoring the release and therapeutic effect of ICG by fluorescence spectra and the quantitative evaluation of NIR fluorescence intensity. Remarkably, nanoparticles can also reinforce antitumor efficacy through photodynamic therapy and GSH depletion property. This study provides new insights into designing turn-on theranostic systems.


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