Layer-by-layer engineered polyelectrolyte microcapsules studied by ToF-SIMS and related analytical techniques

2010 ◽  
Vol 43 (1-2) ◽  
pp. 649-653 ◽  
Author(s):  
Yu-Sheng Yin ◽  
Shiou-Ling Lei ◽  
Yu-Wen Chen ◽  
Yong-Chien Ling
Keyword(s):  
Analytical Techniques ◽  
Layer By Layer ◽  
Polyelectrolyte Microcapsules ◽  
Tof Sims

scholarly journals ToF-SIMS and AFM Characterization of Brown Cosmetic Contact Lenses: From Structural Analysis to the Identification of Pigments

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Seon Hee Kim ◽  
Jihye Lee ◽  
Yun Jung Jang ◽  
Kang-Bong Lee ◽  
Yeonhee Lee
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Contact Lenses ◽  
Analytical Techniques ◽  
Pigment Layer ◽  
Force Microscopy ◽  
Soft Contact Lenses ◽  
Atomic Force ◽  
Tof Sims ◽  
The Cross ◽  
Specific Fragment

Over the years, soft contact lenses for vision correction and cosmetic and therapeutic purposes have been greatly improved. For cosmetic contact lenses, the pigments need to be nontoxic, and the position of the pigment layer is particularly important because of the risks posed by pigment elution and the roughness of the lens surface. In this paper, we characterized the properties of brown cosmetic contact lenses made by three different manufacturers using surface analytical techniques. The surface topographies of the noncolored and colored parts were obtained by atomic force microscopy (AFM), and the position and composition of the pigment layer were determined by analyzing the cross section of the contact lenses using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The influence of pigment location on surface roughness was also examined. In addition, to find the method of the evaluation for the risk of surface elution of the pigments in the colored parts, the mass spectra and ion images of the surfaces were obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) with a new sample preparation. From the ToF-SIMS spectra, we observed specific fragment ions of the poly(hydroxyethyl methacrylate) (PHEMA) polymer and found differences in the composition of the pigment layer depending on the manufacturers. The cross-sectioned image and 3D chemical characterizations of metallic and specific ions in the brown cosmetic contact lenses clearly indicated the spatial distribution and location of the pigment layer that can be used for the evaluation of pigment elution.

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.

scholarly journals Exceptionally preserved ‘skin’ in an Early Cretaceous fish from Colombia

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9479 ◽  
Author(s):  
Andrés Alfonso-Rojas ◽  
Edwin-Alberto Cadena
Keyword(s):  
Soft Tissue ◽  
Elemental Composition ◽  
Molecular Characterization ◽  
Molecular Level ◽  
Analytical Techniques ◽  
Compression Stress ◽  
Exceptional Preservation ◽  
Tof Sims ◽  
Caudal Portion ◽  
External Barrier

Studies of soft tissue, cells and original biomolecular constituents preserved in fossil vertebrates have increased greatly in recent years. Here we report preservation of ‘skin’ with chemical and molecular characterization from a three-dimensionally preserved caudal portion of an aspidorhynchid Cretaceous fish from the equatorial Barremian of Colombia, increasing the number of localities for which exceptional preservation is known. We applied several analytical techniques including SEM-EDS, FTIR and ToF-SIMS to characterize the micromorphology and molecular and elemental composition of this fossil. Here, we show that the fossilized ‘skin’ exhibits similarities with those from extant fish, including the wrinkles after suffering compression stress and flexibility, as well as architectural and tissue aspects of the two main layers (epidermis and dermis). This similarity extends also to the molecular level, with the demonstrated preservation of potential residues of original proteins not consistent with a bacterial source. Our results show a potential preservation mechanism where scales may have acted as an external barrier and together with an internal phosphate layer resulting from the degradation of the dermis itself creating an encapsulated environment for the integument.

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