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multiphoton imaging

James R Thunes, Julie A Phillippi, Thomas G Gleason, David A Vorp, Spandan Maiti
High lethality of aortic dissection necessitates accurate predictive metrics for dissection risk assessment. The not infrequent incidence of dissection at aortic diameters <5.5 cm, the current threshold guideline for surgical intervention (Nishimura et al., 2014), indicates an unmet need for improved evidence-based risk stratification metrics. Meeting this need requires a fundamental understanding of the structural mechanisms responsible for dissection evolution within the vessel wall. We present a structural model of the repeating lamellar structure of the aortic media comprised of elastic lamellae and collagen fiber networks, the primary load-bearing components of the vessel wall...
February 8, 2018: Journal of Biomechanics
Hiba Natsheh, Elka Touitou
The goal of this work was to investigate a new nasal carrier for enhanced drug delivery to brain, we call Phospholipid Magnesome. The system contains soft phospholipid vesicles, composed of phospholipid, water, propylene glycol, magnesium salt, and the mucoadhesive polymer, alginate. The carrier was characterized by various methods: electron microscopy, calorimetry, and dynamic light scattering. The ability of the carrier's vesicles to entrap various molecules was studied by CLSM and ultracentrifugation combined with HPLC quantification...
March 9, 2018: Drug Delivery and Translational Research
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
Chi Ching Goh, Maximilien Evrard, Shu Zhen Chong, Yingrou Tan, Leonard De Li Tan, Karen Wei Weng Teng, Wolfgang Weninger, David Laurence Becker, Hong Liang Tey, Evan William Newell, Bin Liu, Lai Guan Ng
Pressure ulcers are a chronic problem for patients or the elderly who require extended periods of bed rest. The formation of ulcers is due to repeated cycles of ischemia-reperfusion (IR), which initiates an inflammatory response. Advanced ulcers disrupt the skin barrier, resulting in further complications. To date, the immunological aspect of skin IR has been understudied, partly due to the complexity of the skin immune cells. Through a combination of mass cytometry, confocal imaging and intravital multiphoton imaging, this study establishes a workflow for multidimensionality single cell analysis of skin myeloid responses in the context of IR injury with high spatiotemporal resolution...
March 6, 2018: European Journal of Immunology
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
Hequn Wang, Thomas Shyr, Michael J Fevola, Gabriela Oana Cula, Georgios N Stamatas
Two-photon fluorescence (TPF) and second harmonic generation (SHG) microscopy provide direct visualization of the skin dermal fibers in vivo. A typical method for analyzing TPF/SHG images involves averaging the image intensity and therefore disregarding the spatial distribution information. The goal of this study is to develop an algorithm to document age-related effects of the dermal matrix. TPF and SHG images were acquired from the upper inner arm, volar forearm, and cheek of female volunteers of two age groups: 20 to 30 and 60 to 80 years of age...
March 2018: Journal of Biomedical Optics
Roberta Galli, Matthias Meinhardt, Edmund Koch, Gabriele Schackert, Gerald Steiner, Matthias Kirsch, Ortrud Uckermann
Label-free multiphoton imaging constitutes a promising technique for clinical diagnosis and therapeutic monitoring. Corpora amylacea (CoA) are starch-like structures often found in the diseased brain, whose origin and role in nervous pathologies are still a matter of debate. Recently, CoA in the diseased human hippocampus were found to be second harmonic generation (SHG) active. Here, we show that CoA formed in other parts of the diseased brain and in brain neoplasms display a similar SHG activity. The SHG pattern of CoA depended on laser polarization, indicating that a radial structure is responsible for their nonlinear activity...
February 28, 2018: Biomedizinische Technik. Biomedical Engineering
Y X Li, S J Montague, A Brüstle, X F He, C Gillespie, K Gaus, E E Gardiner, W M Lee
In this paper, we introduce two key improvements that overcome limitations of existing polygon scanning microscopes whilst maintaining high spatial and temporal imaging resolution over large fields of view (FOV). First, we proposed a simple and straightforward means to control the scanning angle of the polygon mirror to carry out photomanipulation without resorting to high speed optical modulators. Second, we devised a flexible data sampling method directly leading to higher image contrast by over 2 folds and digital images with 100 megapixels (10240 x 10240) per frame at 0...
February 28, 2018: Journal of Biophotonics
Wataru Ikeda, Ken Sasai, Tsuyoshi Akagi
Most of preclinical cancer studies use xenograft models established from human cell lines or patient-derived cancer cells subcutaneously implanted into the flank of immunocompromised mice. These models are often assumed to represent the original diseases and are valuable tools, at least to some extent, for understanding both the basic biology of cancer and for proof-of-concept studies of molecularly targeted therapies. However, analyzing the cellular behavior of individual components within xenografts, including tumor cells, stromal cells, immune cells, and blood vessels, is challenging...
2018: Methods in Molecular Biology
Sayaka Matsumoto, Junichi Kikuta, Masaru Ishii
The liver is a vital organ in the body. It has various essential functions, including detoxification, protein synthesis, and control of infection. Because of its medical importance, liver diseases such as hepatitis and cirrhosis can be crucial for an individual. Exploring dynamics of living cells in the liver would provide the clues for understanding the pathology. However, due to its technical difficulty, few studies have used intravital liver imaging. To resolve this, we have established a novel imaging system for visualizing liver cell dynamics in living animals...
2018: Methods in Molecular Biology
Jackson LiangYao Li, Chi Ching Goh, Lai Guan Ng
The skin is one of the most physiologically important organs where the organism comes into contact with the external environment and is often a site where pathogen entry first occurs. Thus, a better understanding of the specialized cellular behavior of the immune system in the skin may be important for the improved treatment of diseases. Here, we describe in detail a procedure to image the dorsal mouse ear skin, using a customized ear stage and its associated coverslip holder, with an upright multiphoton microscope...
2018: Methods in Molecular Biology
Asuka Sakata, Satoshi Nishimura
Bone imaging using multiphoton microscopy enables dynamic observation of platelet formation in living animals. Two-photon excitation microscopy is superior to confocal microscopy as it enables deeper tissue penetration, efficient light detection, and reduced phototoxicity. Using this microscopy approach, thrombopoiesis by megakaryocytes is clearly visualized in the skull at significant depth from the surface. Here we describe our microscopy setup and dye recipe for visualization of bone marrow in the mouse skull...
2018: Methods in Molecular Biology
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. To resolve this, we established an intravital bone imaging system using multiphoton microscopy to visualize mature osteoclasts and osteoblasts in living bone.We herein describe the methodology for visualizing the in vivo behavior of bone-resorbing osteoclasts and bone-forming osteoblasts in living bone tissues using intravital multiphoton microscopy...
2018: Methods in Molecular Biology
Xiang-Dong Chen, Shen Li, Bo Du, Yang Dong, Ze-Hao Wang, Guang-Can Guo, Fang-Wen Sun
Multiphoton microscopy (MPM) has been widely used for three-dimensional biological imaging. Here, based on the photon-induced charge state conversion process, we demonstrated a low-power high-resolution MPM with a nitrogen vacancy (NV) center in diamond. Continuous wave green and orange lasers were used to pump and detect the two-photon charge state conversion, respectively. The power of the laser for multiphoton excitation was 40 μW. Both the axial and lateral resolutions were improved approximately 1.5 times compared with confocal microscopy...
February 15, 2018: Optics Letters
A Yu Sdobnov, M E Darvin, E A Genina, A N Bashkatov, J Lademann, V V Tuchin
This paper aims to review recent progress in optical clearing of the skin and over naturally turbid biological tissues and blood using this technique in vivo and in vitro with multiphoton microscopy, confocal Raman microscopy, confocal microscopy, NIR spectroscopy, optical coherence tomography, and laser speckle contrast imaging. Basic principles of the technique, its safety, advantages and limitations are discussed. The application of optical clearing agent on a tissue allows for controlling the optical properties of tissue...
February 3, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Di Li, Pengtao Jing, Lihuan Sun, Yang An, Xinyan Shan, Xinghua Lu, Ding Zhou, Dong Han, Dezhen Shen, Yuechen Zhai, Songnan Qu, Radek Zbořil, Andrey L Rogach
Carbon dots (CDs) have significant potential for use in various fields including biomedicine, bioimaging, and optoelectronics. However, inefficient excitation and emission of CDs in both near-infrared (NIR-I and NIR-II) windows remains an issue. Solving this problem would yield significant improvement in the tissue-penetration depth for in vivo bioimaging with CDs. Here, an NIR absorption band and enhanced NIR fluorescence are both realized through the surface engineering of CDs, exploiting electron-acceptor groups, namely molecules or polymers rich in sulfoxide/carbonyl groups...
February 7, 2018: Advanced Materials
Kexin He, Lili Zhao, Xiaoyang Huang, Ying Ding, Li Liu, Xiang Wang, Min Wang, Yong Zhang, Zhining Fan
Gastric cancer is one of the most common malignancies worldwide. The accurate diagnosis of tumor invasion depth is critical for therapeutic strategy and prognosis. Without fluorescent labelling, multiphoton microscopy (MPM) imaging could directly reveal tissue architecture based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). In this study, we aimed to explore the feasibility of MPM imaging to assess the gastric tumor morphology and infiltration. Unstained slides of 18 fresh gastric tissues with different T staging were examined by multiphoton microscopy...
February 6, 2018: Lasers in Medical Science
S Springer, M Zieger, U C Hipler, K König, J Lademann, M Kaatz, M J Koehler
BACKGROUND: Mucous membranes may be affected by various diseases and the diagnostic accessibility is limited. Multiphoton laser tomography (MPT) is a useful tool for in vivo evaluation of superficial skin structures and might also be useful for the imaging of mucosa. OBJECTIVES: In order to investigate the suitability of MPT for the evaluation of mucous membranes, tissue samples of different donors and anatomical localizations have been imaged. METHODS: Human mucosa samples from the urinary bladder, palatine tonsil and ocular conjunctiva were investigated by MPT and subsequently compared with conventional histology...
February 6, 2018: Skin Research and Technology
Hsiang-Yu Chung, Wei Liu, Qian Cao, Liwei Song, Franz X Kärtner, Guoqing Chang
Wavelength widely tunable femtosecond sources can be implemented by optically filtering the leftmost/rightmost spectral lobes of a broadened spectrum due to self-phase modulation (SPM) dominated fiber-optic nonlinearities. We numerically and experimentally investigate the feasibility of implementing such a tunable source inside optical fibers with negative group-velocity dispersion (GVD). We show that the spectral broadening prior to soliton fission is dominated by SPM and generates well-isolated spectral lobes; filtering the leftmost/rightmost spectral lobes results in energetic femtosecond pulses with the wavelength tuning range more than 400 nm...
February 5, 2018: Optics Express
Youngchan Kim, Sean Warren, Fernando Favero, James Stone, James Clegg, Mark Neil, Carl Paterson, Jonathan Knight, Paul French, Chris Dunsby
This paper reports the development, modelling and application of a semi-random multicore fibre (MCF) design for adaptive multiphoton endoscopy. The MCF was constructed from 55 sub-units, each comprising 7 single mode cores, in a hexagonally close-packed lattice where each sub-unit had a random angular orientation. The resulting fibre had 385 single mode cores and was double-clad for proximal detection of multiphoton excited fluorescence. The random orientation of each sub-unit in the fibre reduces the symmetry of the positions of the cores in the MCF, reducing the intensity of higher diffracted orders away from the central focal spot formed at the distal tip of the fibre and increasing the maximum size of object that can be imaged...
February 5, 2018: Optics Express
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