Anionic Fullerenes, Calixarenes, Coronenes, and Pyrenes as Activators of Oligo/Polyarginines in Model Membranes and Live Cells

2005 ◽  
Vol 127 (4) ◽  
pp. 1114-1115 ◽  
Author(s):  
Florent Perret ◽  
Masamichi Nishihara ◽  
Toshihide Takeuchi ◽  
Shiroh Futaki ◽  
Adina N. Lazar ◽  
...  
Keyword(s):  
Model Membranes ◽  
Live Cells

scholarly journals Nanoscale dynamics of cholesterol in the cell membrane

2019 ◽  
Author(s):  
Kerstin Pinkwart ◽  
Falk Schneider ◽  
Martyna Lukoseviciute ◽  
Tatjana Sauka-Spengler ◽  
Edward Lyman ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Signalling ◽  
Model Membranes ◽  
Live Cells ◽  
Fast Diffusion ◽  
Major Player ◽  
Imaging And Spectroscopy ◽  
Nanoscale Dynamics

AbstractCholesterol constitutes approximately 30-40% of the mammalian plasma membrane — a larger fraction than any other single component. It is a major player in numerous signalling processes as well as molecular membrane architecture. However, our knowledge on dynamics of cholesterol in the plasma membrane is limited which restricts our understanding of the mechanisms regulating its involvement in cell signalling. Here, advanced fluorescence imaging and spectroscopy approaches were applied on in vitro (model membranes) and in vivo (live cells and embryos) membranes to systematically study the nanoscale dynamics of cholesterol in biological membranes. The results show that cholesterol diffuses faster than phospholipids in live membranes, but not in model membranes. The data indicate that diffusion of cholesterol and phospholipids is not correlated with membrane domain partitioning. Instead, our data show that the fast diffusion of cholesterol is due to its nanoscale interactions and localization in the membrane.

scholarly journals Site of fluorescent label modifies interaction of melittin with live cells and model membranes

2015 ◽  
Vol 1848 (10) ◽  
pp. 2031-2039 ◽  
Author(s):  
Elaheh Jamasbi ◽  
Giuseppe D. Ciccotosto ◽  
Julien Tailhades ◽  
Roy M. Robins-Browne ◽  
Cathryn L. Ugalde ◽  
...  
Keyword(s):  
Model Membranes ◽  
Fluorescent Label ◽  
Live Cells

scholarly journals Fluorescence Lifetime Imaging Provides Enhanced Contrast when Imaging the Phase-Sensitive Dye di-4-ANEPPDHQ in Model Membranes and Live Cells

2006 ◽  
Vol 90 (11) ◽  
pp. L80-L82 ◽  
Author(s):  
Dylan M. Owen ◽  
Peter M.P. Lanigan ◽  
Christopher Dunsby ◽  
Ian Munro ◽  
David Grant ◽  
...  
Keyword(s):  
Fluorescence Lifetime ◽  
Model Membranes ◽  
Live Cells ◽  
Fluorescence Lifetime Imaging ◽  
Lifetime Imaging ◽  
Phase Sensitive

scholarly journals Direct Observation of Sophorolipid Micelle Docking in Model Membranes and Cells by Single Particle Studies Reveals Optimal Fusion Conditions

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1291 ◽  
Author(s):  
Pradeep Kumar Singh ◽  
Søren S.-R. Bohr ◽  
Nikos S. Hatzakis
Keyword(s):  
Cancer Cells ◽  
Hela Cells ◽  
Single Particle ◽  
Mammalian Cells ◽  
Model Membranes ◽  
Live Cells ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

Sophorolipids (SLs) are naturally produced glycolipids that acts as drug delivery for a spectrum of biomedical applications, including as an antibacterial antifungal and anticancer agent, where they induce apoptosis selectively in cancerous cells. Despite their utility, the mechanisms underlying their membrane interactions, and consequently cell entry, remains unknown. Here, we combined a single liposome assay to observe directly and quantify the kinetics of interaction of SL micelles with model membrane systems, and single particle studies on live cells to record their interaction with cell membranes and their cytotoxicity. Our single particle readouts revealed several repetitive docking events on individual liposomes and quantified how pH and membrane charges, which are known to vary in cancer cells, affect the docking of SL micelles on model membranes. Docking of sophorolipids micelles was found to be optimal at pH 6.5 and for membranes with −5% negatively charge lipids. Single particle studies on mammalian cells reveled a two-fold increased interaction on Hela cells as compared to HEK-293 cells. This is in line with our cell viability readouts recording an approximate two-fold increased cytotoxicity by SLs interactions for Hela cells as compared to HEK-293 cells. The combined in vitro and cell assays thus support the increased cytotoxicity of SLs on cancer cells to originate from optimal charge and pH interactions between membranes and SL assemblies. We anticipate studies combining quantitative single particle studies on model membranes and live cell may reveal hitherto unknown molecular insights on the interactions of sophorolipid and additional nanocarriers mechanism.

scholarly journals Antimicrobial Peptide Structures: From Model Membranes to Live Cells

2017 ◽  
Vol 24 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Marc-Antoine Sani ◽  
Frances Separovic
Keyword(s):  
Antimicrobial Peptide ◽  
Model Membranes ◽  
Live Cells

4-dimensional, high-resolution imaging of living cells

1992 ◽  
Vol 50 (1) ◽  
pp. 416-417
Author(s):  
Shinya Inoué
Keyword(s):  
Light Microscope ◽  
Living Cells ◽  
Live Cells ◽  
Video Tape ◽  
Active Living ◽  
High Resolution Imaging ◽  
3 Dimensional ◽  
Dynamic Architecture ◽  
Resolution Imaging ◽  
Disk Memory

This paper reports progress of our effort to rapidly capture, and display in time-lapsed mode, the 3-dimensional dynamic architecture of active living cells and developing embryos at the highest resolution of the light microscope. Our approach entails: (A) real-time video tape recording of through-focal, ultrathin optical sections of live cells at the highest resolution of the light microscope; (B) repeat of A at time-lapsed intervals; (C) once each time-lapsed interval, an image at home focus is recorded onto Optical Disk Memory Recorder (OMDR); (D) periods of interest are selected using the OMDR and video tape records; (E) selected stacks of optical sections are converted into plane projections representing different view angles (±4 degrees for stereo view, additional angles when revolving stereos are desired); (F) analysis using A - D.

Multi-mode light microscopy of microtubule assembly dynamics and chromosome movement in vivo and In vitro

1996 ◽  
Vol 54 ◽  
pp. 730-731
Author(s):  
E. D. Salmon ◽  
J. C. Waters ◽  
C. Waterman-Storer
Keyword(s):  
Imaging System ◽  
Ccd Camera ◽  
Transmitted Light ◽  
Microtubule Assembly ◽  
Live Cells ◽  
Optical Efficiency ◽  
Multiple Band ◽  
Multi Mode

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.

Characterization of a Motile Cellular Domain Arising During the Amoebo-Flagellate Transformation of Physarum Polycephalum

1980 ◽  
Vol 38 ◽  
pp. 552-553
Author(s):  
K.I. Pagh ◽  
M.R. Adelman
Keyword(s):  
Cell Shape ◽  
Physarum Polycephalum ◽  
Slime Mold ◽  
Live Cells ◽  
Cellular Domain

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.

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