scholarly journals In vivo flow speed measurement of capillaries by photoacoustic correlation spectroscopy

2011 ◽  
Vol 36 (20) ◽  
pp. 4017 ◽  
Author(s):  
Sung-Liang Chen ◽  
Zhixing Xie ◽  
Paul L. Carson ◽  
Xueding Wang ◽  
L. Jay Guo
Keyword(s):  
Flow Speed ◽  
Correlation Spectroscopy ◽  
Speed Measurement

Photoacoustic correlation spectroscopy for in vivo blood flow speed measurement

2012 ◽  
Author(s):  
Sung-Liang Chen ◽  
Zhixing Xie ◽  
Paul L. Carson ◽  
Xueding Wang ◽  
L. Jay Guo
Keyword(s):  
Blood Flow ◽  
Flow Speed ◽  
Correlation Spectroscopy ◽  
Speed Measurement

scholarly journals In vivo deep-brain blood flow speed measurement through third-harmonic generation imaging excited at the 1700-nm window

2020 ◽  
Vol 11 (5) ◽  
pp. 2738 ◽  
Author(s):  
Hongji Liu ◽  
Xinlin Chen ◽  
Xiangquan Deng ◽  
Ziwei Zhuang ◽  
Shen Tong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Harmonic Generation ◽  
Third Harmonic Generation ◽  
Flow Speed ◽  
Brain Blood Flow ◽  
Third Harmonic ◽  
Speed Measurement ◽  
Deep Brain

scholarly journals Degradation of Drug Delivery Nanocarriers and Payload Release: A Review of Physical Methods for Tracing Nanocarrier Biological Fate

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 770
Author(s):  
Patrick M. Perrigue ◽  
Richard A. Murray ◽  
Angelika Mielcarek ◽  
Agata Henschke ◽  
Sergio E. Moya
Keyword(s):  
Drug Delivery ◽  
Laser Scanning ◽  
Single Photon ◽  
Photon Emission ◽  
Correlation Spectroscopy ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Emission Computed Tomography ◽  
Systemic Delivery

Nanoformulations offer multiple advantages over conventional drug delivery, enhancing solubility, biocompatibility, and bioavailability of drugs. Nanocarriers can be engineered with targeting ligands for reaching specific tissue or cells, thus reducing the side effects of payloads. Following systemic delivery, nanocarriers must deliver encapsulated drugs, usually through nanocarrier degradation. A premature degradation, or the loss of the nanocarrier coating, may prevent the drug’s delivery to the targeted tissue. Despite their importance, stability and degradation of nanocarriers in biological environments are largely not studied in the literature. Here we review techniques for tracing the fate of nanocarriers, focusing on nanocarrier degradation and drug release both intracellularly and in vivo. Intracellularly, we will discuss different fluorescence techniques: confocal laser scanning microscopy, fluorescence correlation spectroscopy, lifetime imaging, flow cytometry, etc. We also consider confocal Raman microscopy as a label-free technique to trace colocalization of nanocarriers and drugs. In vivo we will consider fluorescence and nuclear imaging for tracing nanocarriers. Positron emission tomography and single-photon emission computed tomography are used for a quantitative assessment of nanocarrier and payload biodistribution. Strategies for dual radiolabelling of the nanocarriers and the payload for tracing carrier degradation, as well as the efficacy of the payload delivery in vivo, are also discussed.

Active protein transport through plastid tubules: velocity quantified by fluorescence correlation spectroscopy

2000 ◽  
Vol 113 (22) ◽  
pp. 3921-3930 ◽  
Author(s):  
R.H. Kohler ◽  
P. Schwille ◽  
W.W. Webb ◽  
M.R. Hanson
Keyword(s):  
Active Transport ◽  
Fluorescence Correlation Spectroscopy ◽  
Protein Transport ◽  
Fluorescent Protein ◽  
Correlation Spectroscopy ◽  
Long Distance ◽  
Fluorescence Correlation ◽  
Photon Excitation ◽  
Green Fluorescent

Dynamic tubular projections emanate from plastids in certain cells of vascular plants and are especially prevalent in non-photosynthetic cells. Tubules sometimes connect two or more different plastids and can extend over long distances within a cell, observations that suggest that the tubules may function in distribution of molecules within, to and from plastids. In a new application of two-photon excitation (2PE) fluorescence correlation spectroscopy (FCS), we separated diffusion of fluorescent molecules from active transport in vivo. We quantified the velocities of diffusion versus active transport of green fluorescent protein (GFP) within plastid tubules and in the cytosol in vivo. GFP moves by 3-dimensional (3-D) diffusion both in the cytosol and plastid tubules, but diffusion in tubules is about 50 times and 100 times slower than in the cytosol and an aqueous solution, respectively. Unexpectedly larger GFP units within plastid tubules exhibited active transport with a velocity of about 0.12 microm/second. Active transport might play an important role in the long-distance distribution of large numbers of molecules within the highly viscous stroma of plastid tubules.

scholarly journals A small proportion of Talin molecules transmit forces to achieve muscle attachment in vivo

2018 ◽  
Author(s):  
Sandra B. Lemke ◽  
Thomas Weidemann ◽  
Anna-Lena Cost ◽  
Carsten Grashoff ◽  
Frank Schnorrer
Keyword(s):  
Tissue Mechanics ◽  
Correlation Spectroscopy ◽  
Mechanical Forces ◽  
Muscle Attachment ◽  
Cell Fate Decisions ◽  
Mammalian Cell Lines ◽  
Attachment Sites ◽  
Molecular Forces ◽  
Muscle Attachment Sites

Cells in a developing organism are subjected to particular mechanical forces, which shape tissues and instruct cell fate decisions. How these forces are sensed and transmitted at the molecular level is thus an important question, which has mainly been investigated in cultured cells in vitro. Here, we elucidate how mechanical forces are transmitted in an intact organism. We studied Drosophila muscle attachment sites, which experience high mechanical forces during development and require integrin-mediated adhesion for stable attachment to tendons. Hence, we quantified molecular forces across the essential integrin-binding protein Talin, which links integrin to the actin cytoskeleton. Generating flies expressing three FRET-based Talin tension sensors reporting different force levels between 1 and 11 pN enabled us to quantify physiologically-relevant, molecular forces. By measuring primary Drosophila muscle cells, we demonstrate that Drosophila Talin experiences mechanical forces in cell culture that are similar to those previously reported for Talin in mammalian cell lines. However, in vivo force measurements at developing flight muscle attachment sites revealed that average forces across Talin are comparatively low and decrease even further while attachments mature and tissue-level tension increases. Concomitantly, Talin concentration at attachment sites increases five-fold as quantified by fluorescence correlation spectroscopy, suggesting that only few Talin molecules are mechanically engaged at any given time. We therefore propose that high tissue forces are shared amongst a large excess of adhesion molecules of which less than 15% are experiencing detectable forces at the same time. Our findings define an important new concept of how cells can adapt to changes in tissue mechanics to prevent mechanical failure in vivo.

scholarly journals Extracellular interactions and ligand degradation shape the nodal morphogen gradient

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Yin Wang ◽  
Xi Wang ◽  
Thorsten Wohland ◽  
Karuna Sampath
Keyword(s):  
Correlation Spectroscopy ◽  
Cell Surface Receptor ◽  
Morphogen Gradient ◽  
Axis Formation ◽  
Cellular Interactions ◽  
Fluorescence Correlation ◽  
Selective Ligand ◽  
Surface Receptor ◽  
First Time

The correct distribution and activity of secreted signaling proteins called morphogens is required for many developmental processes. Nodal morphogens play critical roles in embryonic axis formation in many organisms. Models proposed to generate the Nodal gradient include diffusivity, ligand processing, and a temporal activation window. But how the Nodal morphogen gradient forms in vivo remains unclear. Here, we have measured in vivo for the first time, the binding affinity of Nodal ligands to their major cell surface receptor, Acvr2b, and to the Nodal inhibitor, Lefty, by fluorescence cross-correlation spectroscopy. We examined the diffusion coefficient of Nodal ligands and Lefty inhibitors in live zebrafish embryos by fluorescence correlation spectroscopy. We also investigated the contribution of ligand degradation to the Nodal gradient. We show that ligand clearance via degradation shapes the Nodal gradient and correlates with its signaling range. By computational simulations of gradient formation, we demonstrate that diffusivity, extra-cellular interactions, and selective ligand destruction collectively shape the Nodal morphogen gradient.

Local flow speed measurement using tunable ac thermal anemometry

2005 ◽  
Vol 19 (7) ◽  
pp. 1449-1459 ◽  
Author(s):  
Won Seok Chung ◽  
Ohmyoung Kwon ◽  
Joon Sik Lee ◽  
Young Ki Choi ◽  
Seungho Park
Keyword(s):  
Flow Speed ◽  
Local Flow ◽  
Speed Measurement

scholarly journals Driving integrative structural modeling with serial capture affinity purification

2020 ◽  
Vol 117 (50) ◽  
pp. 31861-31870
Author(s):  
Xingyu Liu ◽  
Ying Zhang ◽  
Zhihui Wen ◽  
Yan Hao ◽  
Charles A. S. Banks ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Structural Model ◽  
Protein Complexes ◽  
Affinity Purification ◽  
Quantitative Imaging ◽  
Resonance Energy ◽  
Correlation Spectroscopy ◽  
Cross Linking ◽  
Affinity Enrichment

Streamlined characterization of protein complexes remains a challenge for the study of protein interaction networks. Here we describe serial capture affinity purification (SCAP), in which two separate proteins are tagged with either the HaloTag or the SNAP-tag, permitting a multistep affinity enrichment of specific protein complexes. The multifunctional capabilities of this protein-tagging system also permit in vivo validation of interactions using acceptor photobleaching Förster resonance energy transfer and fluorescence cross-correlation spectroscopy quantitative imaging. By coupling SCAP to cross-linking mass spectrometry, an integrative structural model of the complex of interest can be generated. We demonstrate this approach using the Spindlin1 and SPINDOC protein complex, culminating in a structural model with two SPINDOC molecules docked on one SPIN1 molecule. In this model, SPINDOC interacts with the SPIN1 interface previously shown to bind a lysine and arginine methylated sequence of histone H3. Our approach combines serial affinity purification, live cell imaging, and cross-linking mass spectrometry to build integrative structural models of protein complexes.

scholarly journals In Vivo Effect of Resveratrol-Loaded Solid Lipid Nanoparticles to Relieve Physical Fatigue for Sports Nutrition Supplements

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5302
Author(s):  
Lili Qin ◽  
Tianfeng Lu ◽  
Yao Qin ◽  
Yiwei He ◽  
Ningxin Cui ◽  
...  
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Lipid Nanoparticles ◽  
Correlation Spectroscopy ◽  
Physical Fatigue ◽  
Scanning Calorimetry ◽  
Solid Lipid ◽  
Sequestosome 1

Resveratrol (RSV) is a natural flavonoid polyphenol compound extracted from the plants which shows various biological activities. However, the clinical application of RSV is limited by its poor aqueous solubility, rapid metabolism and poor bioavailability. In this study, resveratrol-loaded solid lipid nanoparticles (RSV- SLNs) was design as a nano-antioxidant against the physical fatigue. The resultant RSV-SLNs were characterized by photon correlation spectroscopy (PCS), transmission electron micrographs (TEM), zeta potential, differential scanning calorimetry (DSC) and Raman spectroscopy pattern. Furthermore, the in vivo anti-fatigue effect assays showed that RSV-SLNs prolonged the mice exhausted time and running distance. The biochemical parameters of blood related to fatigue suggested that RSV-SLNs have potential applications to improve the antioxidant defense of the mice after extensive exercise and confer anti-fatigue capability. Furthermore, the molecular mechanisms of antioxidant by RSV-SLNs supplementation was investigated through the analysis of silent information regulator 2 homolog 1 (SIRT1) protein expression, which demonstrated that it could downregulate the expression of SIRT1 and increase autophagy markers, microtubule-associated protein 1 light chain 3-II (LC3-II) and sequestosome-1 (SQSTM1/p62). These results reveal that the RSV-SLNs may have great potential used as a novel anti-fatigue sports nutritional supplement.

scholarly journals Association with Coregulators Is the Major Determinant Governing Peroxisome Proliferator-activated Receptor Mobility in Living Cells

2006 ◽  
Vol 282 (7) ◽  
pp. 4417-4426 ◽  
Author(s):  
Cicerone Tudor ◽  
Jérôme N. Feige ◽  
Harikishore Pingali ◽  
Vidya Bhushan Lohray ◽  
Walter Wahli ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Molecular Mechanisms ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Living Cells ◽  
Correlation Spectroscopy ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Peroxisome Proliferator Activated Receptors

The nucleus is an extremely dynamic compartment, and protein mobility represents a key factor in transcriptional regulation. We showed in a previous study that the diffusion of peroxisome proliferator-activated receptors (PPARs), a family of nuclear receptors regulating major cellular and metabolic functions, is modulated by ligand binding. In this study, we combine fluorescence correlation spectroscopy, dual color fluorescence cross-correlation microscopy, and fluorescence resonance energy transfer to dissect the molecular mechanisms controlling PPAR mobility and transcriptional activity in living cells. First, we bring new evidence that in vivo a high percentage of PPARs and retinoid X receptors is associated even in the absence of ligand. Second, we demonstrate that coregulator recruitment (and not DNA binding) plays a crucial role in receptor mobility, suggesting that transcriptional complexes are formed prior to promoter binding. In addition, association with coactivators in the absence of a ligand in living cells, both through the N-terminal AB domain and the AF-2 function of the ligand binding domain, provides a molecular basis to explain PPAR constitutive activity.

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