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Two photon microscopy

Hui Wang, Bin Fang, Lin Kong, Xiangzi Li, Zhijun Feng, Yunjun Wu, Kajsa Uvdal, Zhangjun Hu
A novel donor-π-acceptor-π-donor type (D-π-A-π-D') Schiff base derivative (L) has been designed and synthesized. The structure of L is confirmed by single-crystal X-ray diffraction analysis as well. The photophysical properties of compound L were comprehensively investigated by using both experimental and theoretical methods. The results indicate that L exhibits large Stokes shift and moderate two-photon action (2PA) cross-section in the near infrared (NIR) region. Furthermore, the confocal microscopy imaging study demonstrates that compound L could penetrate into cells and target the cellular mitochondria compartment...
March 13, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Sorina Suarasan, Emilia Licarete, Simion Astilean, Ana-Maria Craciun
Nowadays, the non-linear optical effect of two-photon excited (TPE) fluorescence has recently grown in interest in recent years over other optical imaging method, due to improved 3D spatial resolution, deep penetrability and less photodamage of living organism owing to the excitation in near-infrared region (NIR). In parallel, gold nanoparticles (AuNPs) have gain considerable attention for NIR TPE bio-imaging applications due to their appealing ability to generate strong intrinsic photoluminescence (PL). Here, we demonstrate the capability of differently shaped gelatin-coated AuNPs to perform as reliable label-free contrast agents for the non-invasive NIR imaging of NIH:OVCAR-3 ovary cancer cells via TPE Fluorescence Lifetime Imaging Microscopy (FLIM)...
March 14, 2018: Colloids and Surfaces. B, Biointerfaces
Takafumi Inoue
TI Workbench is a software package that serves as a control and analysis center for cellular imaging and electrophysiological experiments. It is unique among general-purpose software packages where it integrates the control of cellular imaging and electrophysiological devices, as well as sophisticated data analyses, which provides superior usability in imaging experiments combined with electrophysiology. During the development over the last 20 years, the range of supported image acquisition devices has expanded from cooled charge-coupled device (CCD) cameras to multi-photon microscope systems...
March 15, 2018: Microscopy
Alexander Mikhaylov, Sophie de Reguardati, Jüri Pahapill, Patrik R Callis, Bern Kohler, Aleksander Rebane
Fluorescent DNA base analogs and intrinsic fluorophores are gaining importance for multiphoton microscopy and imaging, however, their quantitative nonlinear excitation properties have been poorly documented. Here we present the two-photon absorption (2PA) spectra of 2-aminopurine (2AP), 7-methyl guanosine (7MG), isoxanthopterin (IXP), 6-methyl isoxanthopterin (6MI), as well as L-tryptophan (L-trp) and 3-methylindole (3MI) in aqueous solution and some organic solvents measured in the wavelength range 550 - 810 nm using femtosecond two-photon excited fluorescence (2PEF) and nonlinear transmission (NLT) methods...
February 1, 2018: Biomedical Optics Express
Patrick Belikan, Ulrike Bühler, Christina Wolf, Gautam K Pramanik, René Gollan, Frauke Zipp, Volker Siffrin
Multiple sclerosis (MS) is the most common chronic inflammatory demyelinating disease of the CNS. Myelin-specific CD4+ Th lymphocytes are known to play a major role in both MS and its animal model experimental autoimmune encephalomyelitis (EAE). CCR7 is a critical element for immune cell trafficking and recirculation, that is, lymph node homing, under homeostatic conditions; blocking CCR7+ central memory cells from egress of lymph nodes is a therapeutic approach in MS. To define the effect of CD4+ T cell-specific constitutive deletion of CCR7 in the priming and effector phase in EAE, we used an active EAE approach in T cell reconstituted Rag1-/- mice, as well as adoptive transfer EAE, in which mice received in vitro-primed CCR7-/- or CCR7+/+ myelin Ag TCR-transgenic 2d2 Th17 cells...
March 16, 2018: Journal of Immunology: Official Journal of the American Association of Immunologists
Lisa Menegazzo, Valentina Scattolini, Roberta Cappellari, Benedetta Maria Bonora, Mattia Albiero, Mario Bortolozzi, Filippo Romanato, Giulio Ceolotto, Saula Vigili de Kreutzeberg, Angelo Avogaro, Gian Paolo Fadini
AIMS: Diabetes is associated with an excess release of neutrophil extracellular traps (NETs) and an enhanced NETosis, a neutrophil cell death programme instrumental to anti-microbial defences, but also involved in tissue damage. We herein investigated whether the antidiabetic drug metformin protects against NETosis. METHODS: We measured NET components in the plasma of patients with pre-diabetes who were randomized to receive metformin or placebo for 2 months. To control for the effect on glucose, we also measured NET components in the plasma of patients with type 2 diabetes before and after treatment with insulin or dapagliflozin...
March 15, 2018: Acta Diabetologica
Jens Neumann, Sophie Henneberg, Susanne von Kenne, Niklas Nolte, Andreas J Müller, Burkhart Schraven, Michael W Görtler, Klaus G Reymann, Matthias Gunzer, Monika Riek-Burchardt
Inflammation plays an important role in the pathogenesis of ischemic stroke including an acute and prolonged inflammatory process. The role of neutrophil granulocytes as first driver of the immune reaction from the blood site is under debate due to controversial findings. In bone marrow chimeric mice we were able to study the dynamics of tdTomato-expressing neutrophils and GFP-expressing microglia after photothrombosis using intravital two-photon microscopy. We demonstrate the infiltration of neutrophils into the brain parenchyma and confirm a long-lasting contact between neutrophils and microglia as well as an uptake of neutrophils by microglia clearing the brain from peripheral immune cells...
2018: PloS One
Shulian Wu, Yudian Huang, Qinggong Tang, Zhifang Li, Hannah Horng, Jiatian Li, Zaihua Wu, Yu Chen, Hui Li
Preoperative neoadjuvant treatment in locally advanced breast cancer is recognized as an effective adjuvant therapy, as it improves treatment outcomes. However, the potential complications remain a threat, so there is an urgent clinical need to assess both the tumor response and changes in its microenvironment using non-invasive and precise identification techniques. Here, two-photon microscopy was employed to detect morphological alterations in breast cancer progression and recession throughout chemotherapy...
March 1, 2018: Biomedical Optics Express
Koshonna Brown, Ted Thurn, Lun Xin, William Liu, Remon Bazak, Si Chen, Barry Lai, Stefan Vogt, Chris Jacobsen, Tatjana Paunesku, Gayle E Woloschak
Titanium dioxide (TiO2 ) nanoparticles are produced for many different purposes, including development of therapeutic and diagnostic nanoparticles for cancer detection and treatment, drug delivery, induction of DNA double-strand breaks, and imaging of specific cells and subcellular structures. Currently, the use of optical microscopy, an imaging technique most accessible to biology and medical pathology, to detect TiO2 nanoparticles in cells and tissues ex vivo is limited with low detection limits, while more sensitive imaging methods (transmission electron microscopy, X-ray fluorescence microscopy, etc...
January 2018: Nano Research
Krzysztof Kucharz, Martin Lauritzen
Cortical spreading depolarization waves, the cause underlying migraine aura, are also the markers and mechanism of pathology in the acutely injured human brain. Propagation of spreading depolarization wave uniquely depends on the interaction between presynaptic and postsynaptic glutamate N-methyl-d-aspartate receptors (NMDARs). In the normally perfused brain, even a single wave causes a massive depolarization of neurons and glia, which results in transient loss of neuronal function and depression of the ongoing electrocorticographic activity...
March 12, 2018: Brain: a Journal of Neurology
Jue Hou, Joshua Williams, Elliot Botvinick, Eric Potma, Bruce J Tromberg
Label-free non-linear optical microscopy (NLOM) based on two-photon excited fluorescence (TPEF) from cofactors Nicotinamide Adenine Dinucleotide (NADH) and Flavin Adenine Dinucleotide (FAD+) is widely used for high-resolution cellular redox imaging. In this work, we combined three, label-free NLOM imaging methods to quantitatively characterize breast cancer cells and their relative invasive potential: 1) TPEF optical redox ratio (ORR = FAD+/NADH + FAD+), 2) coherent Raman scattering (CRS) of cellular lipids, and 3) second harmonic generation (SHG) of extracellular matrix (ECM) collagen...
March 13, 2018: Cancer Research
Ralitza Staneva, Jorge Barbazan, Anthony Simon, Danijela Matic Vignjevic, Denis Krndija
Cell migration is a process that ensures correct cell localization and function in development and homeostasis. In disease such as cancer, cells acquire an upregulated migratory capacity that leads to their dissemination throughout the body. Live imaging of cell migration allows for better understanding of cell behaviors in development, adult tissue homeostasis and disease. We have optimized live imaging procedures to track cell migration in adult murine tissue explants derived from: (1) healthy gut; (2) primary intestinal carcinoma; and (3) the liver, a common metastatic site...
2018: Methods in Molecular Biology
Meng-Jia Sun, Yingying Liu, Yaming Yan, Rui Li, Qiang Shi, Yong Sheng Zhao, Yu-Wu Zhong, Jiannian Yao
Real-time visualization of assembly processes and sophisticated signal processing at the nanoscale are two challenging topics in photonic nanomaterials. Here, high-quality light-harvesting crystalline nanorods were developed by the co-assembly of two polypyridyl Ir(III) and Ru(II) metallophosphors, behaving as the antenna chromophore and energy acceptor, respectively. By using a one-pot or stepwise growth condition, homogeneous and multi-block heterojunction nanorods were prepared respectively. These nanostructures display multi-color phosphorescence from green to red due to the efficient triplet energy transfer and light-harvesting capability at low acceptor doping ratios...
March 9, 2018: Journal of the American Chemical Society
Haidong Li, Qichao Yao, Feng Xu, Ning Xu, Xuechao Ma, Jiangli Fan, Saran Long, Jianjun Du, Jingyun Wang, Xiaojun Peng
Nitroxyl (HNO), one electron reduced and protonated form of nitric oxide (NO), plays vital in various biological functions and pharmacological activities, such as mediating β-agonist dobutamine, inhibiting the activity of enzyme and treating cardiovascular diseases. However, the accurate mechanism of HNO in living cells is not thoroughly understood due to lacking of effective methods. In this work, a novel two-photon fluorescent probe TP-HNO was designed and synthesized based on 6-hydroxyl-quinonline-2-benzothiazole derivatives through introducing 2-(diphenylphosphino)benzoate as the ideal HNO recognition unit, which demonstrated the merits of outstanding selectivity, excellent sensitivity (DL 0...
March 8, 2018: Analytical Chemistry
Andrea Filippi, Eleonora Dal Sasso, Laura Iop, Andrea Armani, Michele Gintoli, Marco Sandri, Gino Gerosa, Filippo Romanato, Giulia Borile
Label-free microscopy is a very powerful technique that can be applied to study samples with no need for exogenous fluorescent probes, keeping the main benefits of multiphoton microscopy, such as longer penetration depths and intrinsic optical sectioning while enabling serial multitechniques examinations on the same specimen. Among the many label-free microscopy methods, harmonic generation (HG) is one of the most intriguing methods due to its generally low photo-toxicity and relative ease of implementation...
March 2018: Journal of Biomedical Optics
Junichi Kikuta, Masaru Ishii
Bone is continually remodeled by bone-resorbing osteoclasts and bone-forming osteoblasts. Although it has long been believed that bone homeostasis is tightly regulated by communication between osteoclasts and osteoblasts, the fundamental process and dynamics have remained elusive. We originally established an advanced imaging system to visualize living bone tissues using intravital two-photon microscopy. By means of this system, we revealed the in vivo behavior of bone-resorbing osteoclasts and bone-forming osteoblasts in bone tissues...
2018: Clinical Calcium
Monica Manglani, Dorian B McGavern
Innate and adaptive immune interactions within the central nervous system (CNS) and surrounding meninges contribute significantly to neural homeostasis as well as a variety of different neurological disorders. Two-photon laser scanning microscopy is a deep tissue imaging technique that provides a means to image immune cell dynamics and interactions in the living CNS with high spatial and temporal resolution. Optical access to the brain and meninges can be achieved through the creation of thinned skull windows, which can be made without inducing damage and inflammation in the underlying tissue...
February 21, 2018: Current Protocols in Immunology
Marc Aurel Busche
The use of in vivo two-photon microscopy in mouse models of Alzheimer's disease (AD) has propelled studies of disease mechanisms and treatments. For instance, this approach allowed for the first time to study in the intact brain the dynamics of individual amyloid plaques, and the effects of anti-amyloid therapies on plaque formation and growth. Moreover, by combining two-photon microscopy with fluorescent calcium indicators, an amyloid-dependent abnormal hyperactivity of cortical and hippocampal neurons was revealed as a primary neuronal impairment, which was not predicted from previous in vitro analyses...
2018: Methods in Molecular Biology
Austin P Spencer, William O Hutson, Shawn Irgen-Gioro, Elad Harel
We demonstrate that high-dimensionality coherent spectroscopy yields "super-resolved" spectra whereby peaks may be localized far below their homogeneous line width by resolving them across multiple, coherently coupled dimensions. We implement this technique using a fifth-order photon-echo spectroscopy called Gradient-Assisted Multidimensional Electronic-Raman Spectroscopy (GAMERS) that combines resonant and non-resonant excitation to disperse the optical response across three spectral dimensions: two involving excitonic transitions and one that encodes phonon energies...
March 7, 2018: Journal of Physical Chemistry Letters
Amel Slimani, Delphine Tardivo, Ivan V Panayotov, Bernard Levallois, Csilla Gergely, Frederic Cuisinier, Hervé Tassery, Thierry Cloitre, Elodie Terrer
Dentin carious lesion is a dynamic process that involves demineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the caries process using the collagen two-photon excitation fluorescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries Detection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG intensities of enamel and dentin were highly altered during the caries process...
March 6, 2018: Caries Research
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