Cationic liposome–DNA complexes: from liquid crystal science to gene delivery applications

2006 ◽  
Vol 364 (1847) ◽  
pp. 2573-2596 ◽  
Author(s):  
Cyrus R Safinya ◽  
Kai Ewert ◽  
Ayesha Ahmad ◽  
Heather M Evans ◽  
Uri Raviv ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Laser Scanning ◽  
Liquid Crystalline ◽  
Transfection Efficiency ◽  
Three Dimensional ◽  
Cationic Liposome ◽  
Laser Scanning Confocal Microscopy ◽  
Dna Complexes ◽  
Scanning Confocal Microscopy ◽  
Crystalline Nature

At present, there is an unprecedented level of interest in the properties and structures of complexes consisting of DNA mixed with oppositely charged cationic liposomes (CLs). The interest arises because the complexes mimic natural viruses as chemical carriers of DNA into cells in worldwide human gene therapy clinical trials. However, since our understanding of the mechanisms of action of CL–DNA complexes interacting with cells remains poor, significant additional insights and discoveries will be required before the development of efficient chemical carriers suitable for long-term therapeutic applications. Recent studies describe synchrotron X-ray diffraction, which has revealed the liquid crystalline nature of CL–DNA complexes, and three-dimensional laser-scanning confocal microscopy, which reveals CL–DNA pathways and interactions with cells. The importance of the liquid crystalline structures in biological function is revealed in the application of these modern techniques in combination with functional transfection efficiency measurements, which shows that the mechanism of gene release from complexes in the cell cytoplasm is dependent on their precise liquid crystalline nature and the physical and chemical parameters (for example, the membrane charge density) of the complexes. In §5 , we describe some recent new results aimed at developing bionanotube vectors for gene delivery.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

Automated 3-D cell population analysis in thick tissue sections using laser-scanning confocal-microscopy data

1993 ◽  
Vol 51 ◽  
pp. 562-563
Author(s):  
Hakan Ancin
Keyword(s):  
Laser Scanning ◽  
Population Analysis ◽  
Three Dimensional ◽  
Large Data ◽  
Laser Scanning Confocal Microscopy ◽  
Tissue Slices ◽  
Scanning Confocal Microscopy ◽  
Tissue Sections ◽  
Spatially Adaptive ◽  
Microscopy Data

This paper presents methods for performing detailed quantitative automated three dimensional (3-D) analysis of cell populations in thick tissue sections while preserving the relative 3-D locations of cells. Specifically, the method disambiguates overlapping clusters of cells, and accurately measures the volume, 3-D location, and shape parameters for each cell. Finally, the entire population of cells is analyzed to detect patterns and groupings with respect to various combinations of cell properties. All of the above is accomplished with zero subjective bias.In this method, a laser-scanning confocal light microscope (LSCM) is used to collect optical sections through the entire thickness (100 - 500μm) of fluorescently-labelled tissue slices. The acquired stack of optical slices is first subjected to axial deblurring using the expectation maximization (EM) algorithm. The resulting isotropic 3-D image is segmented using a spatially-adaptive Poisson based image segmentation algorithm with region-dependent smoothing parameters. Extracting the voxels that were labelled as "foreground" into an active voxel data structure results in a large data reduction.

Three-Dimensional Laser-Scanning Confocal Microscopy of In Situ Hybridization in the Skin

1994 ◽  
Vol 16 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Stephen E. Mahoney ◽  
Stephen W. Paddock ◽  
Louis C. Smith ◽  
Dorothy E. Lewis ◽  
Madeleine Duvic
Keyword(s):  
In Situ Hybridization ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Scanning Confocal Microscopy

scholarly journals Three-Dimensional Nano-Morphology of Carbon Nanotube/Epoxy Filled Poly(methyl methacrylate) Microcapsules

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1387 ◽  
Author(s):  
M. Galip Icduygu ◽  
Meltem Asilturk ◽  
M. Akif Yalcinkaya ◽  
Youssef K. Hamidi ◽  
M. Cengiz Altan
Keyword(s):  
Confocal Microscopy ◽  
Methyl Methacrylate ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Poly Methyl Methacrylate ◽  
Scanning Confocal Microscopy ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Average Size

The three-dimensional nano-morphology of poly(methyl methacrylate; PMMA) microcapsules filled with carbon nanotubes (CNTs) and epoxy resin were investigated by various microscopy methods, including a novel, laser scanning confocal microscopy (LSCM) method. Initially, PMMA microcapsules containing various amounts of CNTs were synthesized by a solvent evaporation method. Scanning electron microscopy analysis showed that pore-free, smooth-surface microcapsules formed with various types of core-shell morphologies. The average size of CNT/epoxy/PMMA microcapsules was shown to decrease from ~52 μm to ~15 μm when mixing speed during synthesis increased from 300 rpm to 1000 rpm. In general, the presence of CNTs resulted in slightly larger microcapsules and higher variations in size. Moreover, three-dimensional scans obtained from confocal microscopy revealed that higher CNT content increased the occurrence and size of CNT aggregates inside the microcapsules. Entrapped submicron air bubbles were also observed inside most microcapsules, particularly within those with higher CNT content.

Some possibilities of representing microcirculation in human spleen

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Paulína Gálfiová ◽  
Ivan Varga ◽  
Martin Kopáni ◽  
Peter Michalka ◽  
Jana Michalková ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
The Other ◽  
Corrosion Casts ◽  
Histochemical Analysis ◽  
Human Spleen ◽  
Scanning Confocal Microscopy ◽  
Scanning Electron

AbstractThe representation of microcirculation can be approached in several ways. One of the possibilities is to represent the endothelium (endothelial or sinus lining cells) and their basement membrane on the basis of detecting the known components and the expression of the surface antigenes by the methods of immuno-, enzyme- or lectino-histochemical analysis, or by staining or impregnation histological methods. The other possibility is the examination of samples by transmission and scanning electron microscopy. For three-dimensional demonstration corrosion casts techniques or laser scanning confocal microscopy can be used. In this paper we describe the survey of immuno-, enzyme- and lectino-histochemical characteristics of selected components of microcirculation and our own results of its demonstration in human spleen.

Microtubules and mitotic cycle phase modulate spatiotemporal distributions of F-actin and myosin II in Drosophila syncytial blastoderm embryos

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1767-1787 ◽  
Author(s):  
V.E. Foe ◽  
C.M. Field ◽  
G.M. Odell
Keyword(s):  
Laser Scanning ◽  
Myosin Ii ◽  
Three Dimensional ◽  
Time Lapse ◽  
Laser Scanning Confocal Microscopy ◽  
Cycle Phase ◽  
Filamentous Actin ◽  
Mitotic Apparatus ◽  
Scanning Confocal Microscopy ◽  
Drug Treatments

We studied cyclic reorganizations of filamentous actin, myosin II and microtubules in syncytial Drosophila blastoderms using drug treatments, time-lapse movies and laser scanning confocal microscopy of fixed stained embryos (including multiprobe three-dimensional reconstructions). Our observations imply interactions between microtubules and the actomyosin cytoskeleton. They provide evidence that filamentous actin and cytoplasmic myosin II are transported along microtubules towards microtubule plus ends, with actin and myosin exhibiting different affinities for the cell's cortex. Our studies further reveal that cell cycle phase modulates the amounts of both polymerized actin and myosin II associated with the cortex. We analogize pseudocleavage furrow formation in the Drosophila blastoderm with how the mitotic apparatus positions the cleavage furrow for standard cytokinesis, and relate our findings to polar relaxation/global contraction mechanisms for furrow formation.

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