Read by QxMD icon Read

fluorescence lifetime imaging microscopy

J Panek, E Koziolova, P Stepanek, T Etrych, O Janouskova
Nanocarriers bearing anticancer drugs are promising candidates to improve the efficacy of cancer therapy and minimize side effects. The most potent cytostatics used in the treatment of various cancers are anthracyclines, e.g. doxorubicin or pirarubicin. Recently, polymer therapeutics carrying anthracyclines have been intensively studied. The precise characterization of in vitro nanocarrier biological behavior brings a better understanding of the nanocarrier characteristics and enables prediction of the behavior of the nanocarrier during in vivo application...
October 20, 2016: Physiological Research
Tamar Zahavi, Gilad Yahav, Yael Shimshon, Sivan Gershanov, Luna Kaduri, Amir Sonnenblick, Dror Fixler, Asher Y Salmon, Mali Salmon-Divon
Worldwide, more than one million women are diagnosed with breast cancer every year, making it the most common female malignancy in the developed world. Germline mutations in BRCA1 and BRCA2 genes are estimated to increase the risk for developing breast cancer by up to 87%. From a clinical point of view, identification of BRCA1 and BRCA2 mutation carriers offers an opportunity to early identify or prevent the development of malignancy; therefore the ability to determine which women are more likely to carry BRCA1 or BRCA2 mutations is of great importance...
October 6, 2016: Biochemical and Biophysical Research Communications
Sara Sameni, Adeela Syed, J Lawrence Marsh, Michelle A Digman
Huntington disease (HD) is an autosomal neurodegenerative disorder caused by the expansion of Polyglutamine (polyQ) in exon 1 of the Huntingtin protein. Glutamine repeats below 36 are considered normal while repeats above 40 lead to HD. Impairment in energy metabolism is a common trend in Huntington pathogenesis; however, this effect is not fully understood. Here, we used the phasor approach and Fluorescence Lifetime Imaging Microscopy (FLIM) to measure changes between free and bound fractions of NADH as a indirect measure of metabolic alteration in living cells...
October 7, 2016: Scientific Reports
Debasis Banik, Arpita Roy, Niloy Kundu, Nilmoni Sarkar
In this article, we have investigated the modulation of excited state intramolecular double proton transfer (ESIDPT) dynamics of 2,2'-bipyridine-3,3'-diol (BP(OH)2) in two crown ethers namely 18-Crown-6 (18C6) and 15-Crown-5 (15C5). From steady-state UV-Visible measurements, we have shown that there is no significant interaction between dienol tautomeric form (DE) of BP(OH)2 and two crown ethers (CEs). However, in presence of CEs an additional emission band (~ 415 nm) is generated along with the diketo tautomer (DK) band (~ 465 nm)...
October 6, 2016: Journal of Physical Chemistry. B
Jacek T Mika, Alexander J Thompson, Michael R Dent, Nicholas J Brooks, Jan Michiels, Johan Hofkens, Marina K Kuimova
The viscosity is a highly important parameter within the cell membrane, affecting the diffusion of small molecules and, hence, controlling the rates of intracellular reactions. There is significant interest in the direct, quantitative assessment of membrane viscosity. Here we report the use of fluorescence lifetime imaging microscopy of the molecular rotor BODIPY C10 in the membranes of live Escherichia coli bacteria to permit direct quantification of the viscosity. Using this approach, we investigated the viscosity in live E...
October 4, 2016: Biophysical Journal
Suman Ranjit, Alexander Dvornikov, Moshe Levi, Seth Furgeson, Enrico Gratton
Phasor approach to fluorescence lifetime microscopy is used to study development of fibrosis in the unilateral ureteral obstruction model (UUO) of kidney in mice. Traditional phasor analysis has been modified to create a multiparametric analysis scheme that splits the phasor points in four equidistance segments based on the height of peak of the phasor distribution and calculates six parameters including average phasor positions, the shape of each segment, the angle of the distribution and the number of points in each segment...
September 1, 2016: Biomedical Optics Express
Sebina Shrestha, Michael J Serafino, Jesus Rico-Jimenez, Jesung Park, Xi Chen, Siqin Zhaorigetu, Brian L Walton, Javier A Jo, Brian E Applegate
Multimodal imaging probes a variety of tissue properties in a single image acquisition by merging complimentary imaging technologies. Exploiting synergies amongst the data, algorithms can be developed that lead to better tissue characterization than could be accomplished by the constituent imaging modalities taken alone. The combination of optical coherence tomography (OCT) with fluorescence lifetime imaging microscopy (FLIM) provides access to detailed tissue morphology and local biochemistry. The optical system described here merges 1310 nm swept-source OCT with time-domain FLIM having excitation at 355 and 532 nm...
September 1, 2016: Biomedical Optics Express
Mireia Perez-Camps, Jing Tian, Serene C Chng, Kai Pin Sem, Thankiah Sudhaharan, Cathleen Teh, Malte Wachsmuth, Vladimir Korzh, Sohail Ahmed, Bruno Reversade
Formation of the three embryonic germ layers is a fundamental developmental process that initiates differentiation. How the zebrafish pluripotency factor Pou5f3 (homologous to mammalian Oct4) drives lineage commitment is unclear. Here, we introduce fluorescence lifetime imaging microscopy and fluorescence correlation spectroscopy to assess the formation of Pou5f3 complexes with other transcription factors in real-time in gastrulating zebrafish embryos. We show, at single-cell resolution in vivo, that Pou5f3 complexes with Nanog to pattern mesendoderm differentiation at the blastula stage...
September 29, 2016: ELife
Rachel Cinco, Michelle A Digman, Enrico Gratton, Ulrike Luderer
Previous work characterizing ovarian bioenergetics has defined follicular metabolism by measuring metabolic byproducts in culture media. However, culture conditions perturb the native state of the follicle, and these methods do not distinguish between metabolism occurring within oocytes or granulosa cells. We applied the phasor approach to fluorescent lifetime imaging microscopy (Phasor FLIM) at 740 nm 2-photon excitation to examine the spatial distribution of free and protein-bound nicotinamide adenine dinucleotide hydride (NADH) during primordial through preovulatory stages of follicular development in fresh ex vivo murine neonatal and gonadotropin stimulated pre-pubertal ovaries...
September 28, 2016: Biology of Reproduction
Stephen C Harward, Nathan G Hedrick, Charles E Hall, Paula Parra-Bueno, Teresa A Milner, Enhui Pan, Tal Laviv, Barbara L Hempstead, Ryohei Yasuda, James O McNamara
Brain-derived neurotrophic factor (BDNF) and its receptor TrkB are crucial for many forms of neuronal plasticity, including structural long-term potentiation (sLTP), which is a correlate of an animal's learning. However, it is unknown whether BDNF release and TrkB activation occur during sLTP, and if so, when and where. Here, using a fluorescence resonance energy transfer-based sensor for TrkB and two-photon fluorescence lifetime imaging microscopy, we monitor TrkB activity in single dendritic spines of CA1 pyramidal neurons in cultured murine hippocampal slices...
September 28, 2016: Nature
Przemysław Krawczyk, Beata Jędrzejewska, Marek Pietrzak, Tomasz Janek
In this study, the 4-(1H-phenanthro[9,10-d]-imidazol-2-yl)-benzaldehyde (PB1) was investigated as a fluorescent dye. For this reason, the spectroscopic properties in different solvents were thoroughly studied. The experimental data were supported by quantum-chemical calculations using density functional theory. Measurements and theoretical calculations showed that PB1 dye is characterized by the non-monotonic solvatochromism, strongly polar charge transfer excited state, large Stokes' shift, high fluorescence quantum yield and high fluorescence lifetime...
September 19, 2016: Journal of Photochemistry and Photobiology. B, Biology
Hao Zhu, Jiangli Fan, Jianjun Du, Xiaojun Peng
Fluorescent probes have become powerful tools in biosensing and bioimaging because of their high sensitivity, specificity, fast response, and technical simplicity. In the last decades, researchers have made remarkable progress in developing fluorescent probes that respond to changes in microenvironments (e.g., pH, viscosity, and polarity) or quantities of biomolecules of interest (e.g., ions, reactive oxygen species, and enzymes). All of these analytes are specialized to carry out vital functions and are linked to serious disorders in distinct subcellular organelles...
October 18, 2016: Accounts of Chemical Research
Cong Liu, Yen-Liang Liu, Evan P Perillo, Andrew K Dunn, Hsin-Chih Yeh
In the past two decades significant advances have been made in single-molecule detection, which enables the direct observation of single biomolecules at work in real time and under physiological conditions. In particular, the development of single-molecule tracking (SMT) microscopy allows us to monitor the motion paths of individual biomolecules in living systems, unveiling the localization dynamics and transport modalities of the biomolecules that support the development of life. Beyond the capabilities of traditional camera-based tracking techniques, state-of-the-art SMT microscopies developed in recent years can record fluorescence lifetime while tracking a single molecule in the 3D space...
July 2016: IEEE Journal of Selected Topics in Quantum Electronics
Wojciech Grudzinski, Joanna Sagan, Renata Welc, Rafal Luchowski, Wieslaw I Gruszecki
Amphotericin B is a popular antifungal antibiotic, a gold standard in treatment of systemic mycotic infections, due to its high effectiveness. On the other hand, applicability of the drug is limited by its considerable toxicity to patients. Biomembranes are a primary target of physiological activity of amphotericin B and both the pharmacologically desired and toxic side effects of the drug relay on its molecular organization in the lipid phase. In the present work, molecular organization, localization and orientation of amphotericin B, in a single lipid bilayer system, was analysed simultaneously, thanks to application of a confocal fluorescence lifetime imaging microscopy of giant unilamellar vesicles...
2016: Scientific Reports
Gregory Weitsman, Paul R Barber, Lan K Nguyen, Katherine Lawler, Gargi Patel, Natalie Woodman, Muireann T Kelleher, Sarah E Pinder, Mark Rowley, Paul A Ellis, Anand D Purushotham, Anthonius C Coolen, Boris N Kholodenko, Borivoj Vojnovic, Cheryl Gillett, Tony Ng
Overexpression of HER2 is an important prognostic marker, and the only predictive biomarker of response to HER2-targeted therapies in invasive breast cancer. HER2-HER3 dimer has been shown to drive proliferation and tumor progression, and targeting of this dimer with pertuzumab alongside chemotherapy and trastuzumab, has shown significant clinical utility. The purpose of this study was to accurately quantify HER2-HER3 dimerisation in formalin fixed paraffin embedded (FFPE) breast cancer tissue as a novel prognostic biomarker...
July 13, 2016: Oncotarget
Yide Zhang, Aamir A Khan, Genevieve D Vigil, Scott S Howard
We present a series of experiments that demonstrate a super-sensitive chemical imaging technique based on multiphoton frequency-domain fluorescence lifetime imaging microscopy (MPM-FD-FLIM) that shows a 2× improvement in imaging speed compared to the theoretical limit of conventional MPM-FD-FLIM. Additionally, this technique produces unprecedented sensitivity over a large range of fluorescence lifetimes. These results are achieved through simple modifications to data analysis in a conventional MPM-FD-FLIM microscope and are based on an analytical model describing the signal-to-noise ratio (SNR) of a MPM-FD-FLIM system [J...
September 5, 2016: Optics Express
Dongdong Su, Chai Lean Teoh, Nengyue Gao, Qing-Hua Xu, Young-Tae Chang
Intracellular viscosity is a fundamental physical parameter that indicates the functioning of cells. In this work, we developed a simple boron-dipyrromethene (BODIPY)-based probe, BTV, for cellular mitochondria viscosity imaging by coupling a simple BODIPY rotor with a mitochondria-targeting unit. The BTV exhibited a significant fluorescence intensity enhancement of more than 100-fold as the solvent viscosity increased. Also, the probe showed a direct linear relationship between the fluorescence lifetime and the media viscosity, which makes it possible to trace the change of the medium viscosity...
2016: Sensors
Alexander Braun, Nicole M Caesar, Kyvan Dang, Kenneth A Myers
The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes within individual endothelial cells (ECs). These processes are critical for homeostatic maintenance such as wound healing, and are also crucial in promoting tumor growth and metastasis. EC morphology is defined by the organization of the cytoskeleton, a tightly regulated system of actin and microtubule (MT) dynamics that is known to control EC branching, polarity and directional migration, essential components of angiogenesis...
2016: Journal of Visualized Experiments: JoVE
Paweł Mystek, Przemysław Dutka, Magdalena Tworzydło, Marta Dziedzicka-Wasylewska, Agnieszka Polit
G proteins are peripheral membrane proteins which interact with the inner side of the plasma membrane and form part of the signalling cascade activated by G protein-coupled receptors (GPCRs). Since many signalling proteins do not appear to be homogeneously distributed on the cell surface, they associate in particular membrane regions containing specific lipids. Therefore, protein-lipid interactions play a pivotal role in cell signalling. Our previous results showed that although Gαs and Gαi3 prefer different types of membrane domains they are both co-localized with the D1 receptor...
August 25, 2016: Biochimica et Biophysica Acta
Suman Ranjit, Evgenia Dobrinskikh, John Montford, Alexander Dvornikov, Allison Lehman, David J Orlicky, Raphael Nemenoff, Enrico Gratton, Moshe Levi, Seth Furgeson
All forms of progressive renal diseases develop a final pathway of tubulointerstitial fibrosis and glomerulosclerosis. Renal fibrosis is usually quantified using histological staining, a process that is time-consuming and pathologist dependent. Here we develop a fast and operator-independent method to measure fibrosis utilizing the murine unilateral ureteral obstruction model which manifests a time-dependent fibrotic increase in obstructed kidneys while the contralateral kidneys are used as controls. After ureteral obstruction, kidneys were analyzed at 7, 14, and 21 days...
November 2016: Kidney International
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"