Converging layer-by-layer polyelectrolyte microcapsule and cubic lyotropic liquid crystalline nanoparticle approaches for molecular encapsulation

Soft Matter ◽  
2011 ◽  
Vol 7 (9) ◽  
pp. 4257 ◽  
Author(s):  
Chantelle D. Driever ◽  
Xavier Mulet ◽  
Angus P. R. Johnston ◽  
Lynne J. Waddington ◽  
Helmut Thissen ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Layer By Layer ◽  
Molecular Encapsulation ◽  
Polyelectrolyte Microcapsule

scholarly journals Layer-by-Layer Polymer Coating on Discrete Particles of Cubic Lyotropic Liquid Crystalline Dispersions (Cubosomes)

Langmuir ◽  
2013 ◽  
Vol 29 (42) ◽  
pp. 12891-12900 ◽  
Author(s):  
Chantelle D. Driever ◽  
Xavier Mulet ◽  
Lynne J. Waddington ◽  
Almar Postma ◽  
Helmut Thissen ◽  
...  
Keyword(s):  
Polymer Coating ◽  
Liquid Crystalline ◽  
Layer By Layer

scholarly journals Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

2016 ◽  
Vol 7 ◽  
pp. 1905-1917 ◽  
Author(s):  
Nadezhda M Zholobak ◽  
Anton L Popov ◽  
Alexander B Shcherbakov ◽  
Nelly R Popova ◽  
Mykhailo M Guzyk ◽  
...  
Keyword(s):  
Citric Acid ◽  
Solvent Free ◽  
Layer By Layer ◽  
One Pot ◽  
Polyelectrolyte Microcapsules ◽  
Cell Staining ◽  
Polyelectrolyte Microcapsule ◽  
Facile Fabrication ◽  
Fixed Cell

Luminescent organic dots (O-dots) were synthesized via a one-pot, solvent-free thermolysis of citric acid in urea melt. The influence of the ratio of the precursors and the duration of the process on the properties of the O-dots was established and a mechanism of their formation was hypothesized. The multicolour luminescence tunability and toxicity of synthesized O-dots were extensively studied. The possible applications of O-dots for alive/fixed cell staining and labelling of layer-by-layer polyelectrolyte microcapsules were evaluated.

Layer-by-layer-coated lyotropic liquid crystalline nanoparticles for active tumor targeting of rapamycin

Nanomedicine ◽  
2016 ◽  
Vol 11 (22) ◽  
pp. 2975-2996 ◽  
Author(s):  
May S Freag ◽  
Yosra SR Elnaggar ◽  
Doaa A Abdelmonsif ◽  
Ossama Y Abdallah
Keyword(s):  
Tumor Targeting ◽  
Liquid Crystalline ◽  
Layer By Layer ◽  
Liquid Crystalline Nanoparticles

Formation of Calcium Phosphate-Ellagic Acid Composites by Layer by Layer Assembly for Cellular Attachment to Osteoblasts

2012 ◽  
Vol 13 ◽  
pp. 1-17
Author(s):  
Ipsita A. Banerjee ◽  
Karl R. Fath ◽  
Nako Nakatsuka ◽  
Nazmul H. Sarker ◽  
Ipsita A. Banerjee
Keyword(s):  
Calcium Phosphate ◽  
Ellagic Acid ◽  
Liquid Crystalline ◽  
Average Pore Size ◽  
Layer By Layer ◽  
Average Pore ◽  
Assembly Method ◽  
Cellular Attachment ◽  
New Strategy

The quest for new biomaterials to serve as cell scaffolds for applications in tissue engineering is of prime importance. In this work, we investigated microfiber assemblies of Ellagic Acid (EA), a plant polyphenol to serve as scaffolds for attachment and proliferation of osteoblasts. The advantage of Ellagic Acid self-assembling system is its intrinsic ability to order into multiple layers due to its capability to form liquid crystalline assemblies. We prepared ellagic acid-microfiber composites by the layer-by-layer (LBL) assembly method, where collagen (COL), poly-Arginine (poly-R), and calcium phosphate nanocrystals were coated on the surface of ellagic acid microfibers. The attachment of the various layers was confirmed by various spectroscopic and microscopic methods. The samples were found to be porous with an average pore size of 600 nm. The formed microconjugates were biodegradable and supported the growth of human fetal osteoblast (hFOB) cells in vitro. Our findings suggest that this system not only promotes initial cell adhesion but also can be utilized to deliver the vital biological molecule ellagic acid to cells at the scaffold interface and displays a new strategy for the design of biomaterials.

Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

1983 ◽  
Vol 41 ◽  
pp. 646-647
Author(s):  
Joseph A. Zasadzinski
Keyword(s):  
Liquid Crystalline ◽  
Freeze Fracture ◽  
Continuum Theory ◽  
Closed Surfaces ◽  
Straight Line ◽  
Low Weight ◽  
Concentric Spheres ◽  
Membrane Geometry ◽  
Dupin Cyclides ◽  
Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

Structure-property relations of liquid crystalline polymers

1987 ◽  
Vol 45 ◽  
pp. 460-463
Author(s):  
Linda C. Sawyer
Keyword(s):  
Solid State ◽  
Liquid Crystalline ◽  
Structural Model ◽  
Crystalline Polymer ◽  
Liquid Crystalline Polymers ◽  
Mechanical Anisotropy ◽  
Structure Property ◽  
Preparation Methods ◽  
Crystalline Polymers ◽  
Extended Chain

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.

Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

1986 ◽  
Vol 44 ◽  
pp. 348-349
Author(s):  
D.F. Clapin ◽  
V.J.A. Montpetit
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurofibrillary Tangles ◽  
Liquid Crystalline ◽  
Amyloid Fibrils ◽  
Geometric Analysis ◽  
Paired Helical Filaments ◽  
Microscopic Level ◽  
Light Microscopic Level ◽  
Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

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