Search results for "Capsule"
showing 10 items of 223 documents
Multilayer capsules: a promising microencapsulation system for transplantation of pancreatic islets
2001
In 1980, Lim and Sun introduced a microcapsule coated with an alginate/polylysine complex for encapsulation of pancreatic islets. Characteristic to this type of capsule is, that it consists of a plain membrane which is formed during a single procedural step. With such a simple process it is difficult to obtain instantly a membrane optimized with respect to all the properties requested for islet transplantation. To overcome these difficulties, it is recommended to build up the membrane in several consecutive steps, each optimized for a certain property. In this study, we have analysed such a multilayer microcapsule for the encapsulation of pancreatic islets. Therefore, empty and islet contai…
General Applications of Viscoelastics
2000
The many and diverse physicochemical characteristics of viscoelastic substances impose both their desired and undesired effects clinically. As there is no single ideal substance to meet clinical stipulations, individual viscoelastic characteristics should be considered with respect to demand. Georg Eisner described viscoelastic agents as a tool for space-occupying measures (in tissues, in space or on surfaces) applied by the use of special techniques (Eisner, 1980; Eisner, 1983). In surgery, viscoelastic substances protect tissues and cells from mechanical trauma, serve to separate tissues, occupy space, break away adhesions, stop bleeding, coat, act as manipulative instruments and move tis…
Development of Removable Visual Impact Indicator or Polymer Composite Materials
2021
The prototype of removable visual impact indicator for thermoset polymer composite materials is developed, and its characteristics are experimentally determined. The indicator is a fabric tape glued by epoxy to the surface of the polymer composite. The tape is impregnated with a composition that provides a visual response at the place of an impact on the composite surface. Ball-drop tests demonstrated the increase of the magnitude of the visual response with the impact energy at different substrate hardnesses. The shelf-life and mode of the tape storage until commissioning are determined. Peel tests showed the ability to remove a used indicator without damaging the surface of the composite.
Docetaxel-Loaded Nanoparticles Assembled from β-Cyclodextrin/Calixarene Giant Surfactants: Physicochemical Properties and Cytotoxic Effect in Prostat…
2017
Giant amphiphiles encompassing a hydrophilic β-cyclodextrin (βCD) component and a hydrophobic calix[4]arene (CA4) module undergo self-assembly in aqueous media to afford core-shell nanospheres or nanocapsules, depending on the nanoprecipitation protocol, with high docetaxel (DTX) loading capacity. The blank and loaded nanoparticles have been fully characterized by dynamic light scattering (DLS), ζ-potential measurements and cryo-transmission electron microscopy (cryo-TEM). The data are compatible with the distribution of the drug between the nanoparticle core and the shell, where it is probably anchored by inclusion of the DTX aromatic moieties in βCD cavities. Indeed, the release kinetics …
Guest-Induced Folding of the N-Benzyl Substituents in an Ammonium Resorcinarene Chloride and the Formation of a Halogen-Bonded Dimer of Capsules
2016
In methanol, N-benzyl ammonium resorcinarene chloride (Bn-NARCl) crystallizes as a solvate with the benzyl groups oriented in an open flower-like manner parallel to the cation–anion seam. 1,4-Dioxane as guest triggers a “semi-closed” single-molecule capsule with two benzyl “arms” enclosing the guest. The introduction of halogen bond (XB) donor 1,4-diiodoperfluorobutane (1,4-DIOFB) additionally folds the remaining two benzyl arms thus resulting in a fully closed capsule. Two 1,4-DIOFB molecules bridge two such Bn-NARCl capsules, forming a 2:2:2 XB held dimeric assembly of single-molecule capsules. The peculiar behavior was not observed in the bromide analog under similar experimental conditi…
Inorganic Protection of Polymer Nanocapsules: A Strategy to Improve the Efficiency of Encapsulated Optically Active Molecules
2018
Detection of poly(methylmethacrylate) wear particles in capsule tissue surrounding endoprotheses by pyrolysis gas chromatography
1982
Pyrolysis gas chromatography (PGC) is used to detect polymer wear particles in capsule tissue surrounding endoprotheses implanted with poly(methylmethacrylate) as bone cement. The method allows the detection of the polymer incorporated in tissue even in the range of 1 weight%.
Mass spectrometrical detection of polymer particles in capsule tissue surrounding joint endoprotheses of polyethyleneterephthalate
1982
Pyrolysis mass spectrometry of synthetic high polymers is described. The method is used to detect polymer wear particles in capsule tissue surrounding endoprotheses with polyethyleneterephthalate parts. An approximation of semi-quantitative determination of the polymer wear will be discussed.
Biodegradable lignin nanocontainers
2014
The abundant biomaterial lignin was used to prepare hollow nanocapsules by interfacial polyaddition in inverse miniemulsions. These cross-linked lignin nanocontainers can be loaded with hydrophilic substances which can be released by an enzymatic trigger from natural plant extracts revealing them as potential nanocontainers for agricultural applications.