The in-Vivo Approach: Cell Imaging

To mount an immune response, lymphocytes must recirculate between the blood and lymph nodes, recognize antigens upon contact with specialized presenting cells, proliferate to expand a small number of clonally relevant lymphocytes, differentiate to antibody-producing plasma cells or effector T cells, exit from lymph nodes, migrate to tissues, and engage in host-protective activities. All of these processes involve motility and cellular interactions—events that were hidden from view until recently. Introduced to immunology by three papers in this journal in 2002, in vivo live-cell imaging studies are revealing the behavior of cells mediating adaptive and innate immunity in diverse tissue environments, providing quantitative measurement of cellular motility, interactions, and response dynamics. Here, we review themes emerging from such studies and speculate on the future of immunoimaging.

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Abstract 1065: A New Method for Stem Cell Imaging Using Contrast Ultrasound

Circulation ◽

10.1161/circ.118.suppl_18.s_642-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Wenjin Cui ◽

Xucai Chen ◽

Jianjun Wang ◽

Andrew Fisher ◽

Kang Kim ◽

...

Keyword(s):

Cell Imaging ◽

Pulse Sequence ◽

Mechanical Index ◽

Frequency Spectra ◽

Non Invasive ◽

Density Centrifugation ◽

Transmission Electron ◽

Therapy Strategies ◽

Contrast Ultrasound

Background : Mesenchymal stem cells (MSCs) are a promising new cardiac reparative therapy. The distribution of delivered MSCs is poorly understood due to limited methods to track them in vivo . To test the hypothesis that ultrasound can detect MSCs, gas-filled microbubbles (MBs) were developed for MSC uptake. Methods : Perfluorocarbon gas-filled MBs were synthesized from a biodegradable polymer. Cultured rat and human bone-marrow derived MSCs were dwelled with MBs (12 hrs), washed, and suspended in medium. MSC uptake of MBs and MB retention of gas were confirmed with transmission electron microscopy (TEM) and density centrifugation. Spectral analysis of free MB response to up to 10MHz ultrasound was performed. 2nd harmonic and contrast pulse sequence (CPS) 2D echo imaging (7MHz) of MB-labeled and unlabeled MSCs was performed at a mechanical index (MI) 0.3 and 1.9. Videointensity was measured in 200 frames/capture. Results: Frequency spectra of free MBs contained 2nd and 3rd harmonics, indicating MB non-linearity. TEM showed MBs within MSCs (Figure ). By density centrifugation, MSCs with MBs were less dense than MSCs alone, confirming intracellular MB gas retention. Videointensity (gray scale units) of MSCs containing MBs vs MSCs alone was higher at both low MI (35±2 vs 0±0 harmonic, p<0.005; 21±2 vs 15±0 CPS, p<0.005), and high MI (14±2 vs 6±1 harmonic, p<0.005; 6±2 vs 0±0 CPS, p<0.005). Conclusions : Our acoustically active polymer MBs are internalized by MSCs and render them detectable with ultrasound. Because the polymer degrades slowly, this approach may permit serial non-invasive in vivo ultrasound imaging of MSC fate, thus facilitating optimization of cell therapy strategies.

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A new visible-light-excitable ICT-CHEF-mediated fluorescence ‘turn-on’ probe for the selective detection of Cd2+ in a mixed aqueous system with live-cell imaging

Dalton Transactions ◽

10.1039/c4dt02463j ◽

2015 ◽

Vol 44 (12) ◽

pp. 5763-5770 ◽

Cited By ~ 58

Author(s):

Shyamaprosad Goswami ◽

Krishnendu Aich ◽

Sangita Das ◽

Chitrangada Das Mukhopadhyay ◽

Deblina Sarkar ◽

...

Keyword(s):

Visible Light ◽

Live Cell Imaging ◽

Cell Imaging ◽

Aqueous System ◽

Live Cell ◽

Selective Detection ◽

Turn On ◽

Fluorescence Turn On

A new quinoline based sensor was developed and applied for the selective detection of Cd2+ both in vitro and in vivo.

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Role of Aqueous-Phase Calcination in Synthesis of Ultra-Stable Dye-Embedded Fluorescent Nanoparticles for Cellular Probing

Applied Spectroscopy ◽

10.1177/00037028211027597 ◽

2021 ◽

pp. 000370282110275

Author(s):

Rachel Rex ◽

Soumik Siddhanta ◽

Ishan Barman

Keyword(s):

Silica Nanoparticles ◽

Cell Imaging ◽

Fluorescent Dyes ◽

Aqueous Media ◽

Clinical Diagnostics ◽

Live Cell ◽

Metal Nanoparticle ◽

Superior Performance ◽

Fluorescent Nanoparticles

Fluorescence imaging is a major driver of discovery in biology, and an invaluable asset in clinical diagnostics. To overcome quenching limitations of conventional fluorescent dyes and further improve intensity, nanoparticle-based constructs have been the subject of intense investigation, and within this realm, dye-doped silica-coated nanoparticles have garnered significant attention. Despite their growing popularity in research, fluorescent silica nanoparticles suffer from a significant flaw. The degradation of these nanoparticles in biological media by hydrolytic dissolution is underreported, leading to serious misinterpretations, and limiting their applicability for live cell and in vivo imaging. Here, the development of an ultra-stable, dye-embedded, silica-coated metal nanoparticle is reported, and its superior performance in long-term live cell imaging is demonstrated. While conventional dye-doped silica nanoparticles begin to degrade within an hour in aqueous media, by leveraging a modified liquid calcination process, this new construct is shown to be stable for at least 24 h. The stability of this metal-enhanced fluorescent probe in biologically relevant temperatures and media, and its demonstrated utility for cell imaging, paves the way for its future adoption in biomedical research.

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Synthesis of Carbon Quantum Dot Nanoparticles Derived from Byproducts in Bio-Refinery Process for Cell Imaging and In Vivo Bioimaging

Nanomaterials ◽

10.3390/nano9030387 ◽

2019 ◽

Vol 9 (3) ◽

pp. 387 ◽

Cited By ~ 40

Author(s):

Caoxing Huang ◽

Huiling Dong ◽

Yan Su ◽

Yan Wu ◽

Robert Narron ◽

...

Keyword(s):

Quantum Dot ◽

Cell Imaging ◽

Degradation Products ◽

Green Fluorescence ◽

One Pot ◽

Carbon Nanoparticle ◽

Carbon Quantum Dot ◽

Potential Applications ◽

Main Components

The carbon quantum dot (CQD), a fluorescent carbon nanoparticle, has attracted considerable interest due to its photoluminescent property and promising applications in cell imaging and bioimaging. In this work, biocompatible, photostable, and sustainably sourced CQDs were synthesized from byproducts derived from a biorefinery process using one-pot hydrothermal treatment. The main components of byproducts were the degradation products (autohydrolyzate) of biomass pretreated by autohydrolysis. The as-synthesized CQDs had a size distribution from 2.0–6.0 nm and had high percentage of sp2 and sp3 carbon groups. The CQDs showed blue-green fluorescence with a quantum yield of ~13%, and the fluorescence behaviors were found to be stable with strong resistance to photobleaching and temperature change. In addition, it is found that the as-synthesized CQDs could be used for imaging of cells and tumors, which show potential applications in bioimaging and related fields such as phototherapy and imaging.

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Upconversion NIR-II fluorophores for mitochondria-targeted cancer imaging and photothermal therapy

Nature Communications ◽

10.1038/s41467-020-19945-w ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Hui Zhou ◽

Xiaodong Zeng ◽

Anguo Li ◽

Wenyi Zhou ◽

Lin Tang ◽

...

Keyword(s):

Photothermal Therapy ◽

Biomedical Applications ◽

Cell Imaging ◽

Upconversion Luminescence ◽

Great Promise ◽

Osteosarcoma Cells ◽

Image Guided ◽

Donor Acceptor ◽

Subcellular Resolution

AbstractNIR-II fluorophores have shown great promise for biomedical applications with superior in vivo optical properties. To date, few small-molecule NIR-II fluorophores have been discovered with donor-acceptor-donor (D-A-D) or symmetrical structures, and upconversion-mitochondria-targeted NIR-II dyes have not been reported. Herein, we report development of D-A type thiopyrylium-based NIR-II fluorophores with frequency upconversion luminescence (FUCL) at ~580 nm upon excitation at ~850 nm. H4-PEG-PT can not only quickly and effectively image mitochondria in live or fixed osteosarcoma cells with subcellular resolution at 1 nM, but also efficiently convert optical energy into heat, achieving mitochondria-targeted photothermal cancer therapy without ROS effects. H4-PEG-PT has been further evaluated in vivo and exhibited strong tumor uptake, specific NIR-II signals with high spatial and temporal resolution, and remarkable NIR-II image-guided photothermal therapy. This report presents the first D-A type thiopyrylium NIR-II theranostics for synchronous upconversion-mitochondria-targeted cell imaging, in vivo NIR-II osteosarcoma imaging and excellent photothermal efficiency.

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