The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Maria Helena Andrade Santana - One of the best experts on this subject based on the ideXlab platform.
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Physical Characterization of surface-modified liposomes by incorporation of gangliosides designed for immunotherapies
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004Co-Authors: Maria Helena Ambrosio Zanin, Iris L. Torriani, Ricardo De Lima Zollner, Maria Helena Andrade SantanaAbstract:Abstract Surface-modified liposomes with gangliosides prolong their half life in blood stream that associated to the poor immunogenic properties of gangliosides are potentially useful for applications as immunotherapic vehicles. The Physical characteristics of these biocolloids play an important role on their stability and exposition of the ganglioside antigens to the immunological system. The present work describes the Physical Characterization of liposomes incorporating a monosialoganglioside or a mixture of mono-, di- and trisialogangliosides. The liposomal matrix was composed of either dipalmitoylphosphatidylcholine and cholesterol, or in some preparations dihexadecylphosphate, which was added in order to provide a higher negative charge density on the liposome surface. Both types of liposomes were prepared by the dry phospholipids film hydration method and characterized by their phospholipid and ganglioside content, mean diameter, size distribution, morphology, membrane packing, lamellar structure and phase transition behavior.
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Physical Characterization of surface-modified liposomes by incorporation of gangliosides designed for immunotherapies
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004Co-Authors: Maria Helena Ambrosio Zanin, Iris L. Torriani, Ricardo L. Zollner, Maria Helena Andrade SantanaAbstract:Surface-modified liposomes with gangliosides prolong their half life in blood stream that associated to the poor immunogenic properties of gangliosides are potentially useful for applications as immunotherapic vehicles. The Physical characteristics of these biocolloids play an important role on their stability and exposition of the ganglioside antigens to the immunological system. The present work describes the Physical Characterization of liposomes incorporating a monosialoganglioside or a mixture of mono-, di- and trisialogangliosides. The liposomal matrix was composed of either dipalmitoylphosphatidylcholine and cholesterol, or in some preparations dihexadecylphosphate, which was added in order to provide a higher negative charge density on the liposome surface. Both types of liposomes were prepared by the dry phospholipids film hydration method and characterized by their phospholipid and ganglioside content, mean diameter, size distribution, morphology, membrane packing, lamellar structure and phase transition behavior. (C) 2004 Elsevier B.V. All rights reserved.2514169917518
Takashi Inoue - One of the best experts on this subject based on the ideXlab platform.
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Physical Characterization of a polyolefinic thermoplastic elastomer
Polymer, 1998Co-Authors: Ying Yang, Tsuneo Chiba, Hiromu Saito, Takashi InoueAbstract:Physical Characterization of a commercial polyolefinic thermoplastic elastomer (TPE), Santoprene®, was undertaken to understand the elastomeric nature of the two-phase material in which rubber particles are dispersed in a matrix of polypropylene (PP). Dynamic mechanical analysis showed that the PP matrix contains a small amount of rubber. PP crystal lamellae in rubber particles in a well-annealed sample were observed by transmission electron microscopy, suggesting that PP had been occluded in the rubber phase. Such partial phase-mixing may be caused by homogenization under high shear during dynamic vulcanization. Wide angle X-ray diffraction (WAXD) studies showed that PP crystallites in TPE are smaller than those in neat PP. That is, the occluded rubber in the PP matrix may play the role of impurity to render the smaller crystallites. By WAXD analysis on crystal orientation and its relaxation in stretching and releasing processes, it was shown that the smaller crystallites suffer less plastic deformation and, rather, play the role of tie points to provide the elastic properties of the PP matrix itself. About 40 wt% of process oil was found to be loaded on TPE; however, the oil seems to play a minor role in providing the elastomeric character.
M. Isabel Gobernado-mitre - One of the best experts on this subject based on the ideXlab platform.
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Physical Characterization of commercial polyolefinic thermoplastic elastomers
European Polymer Journal, 2004Co-Authors: Mariano Montoya, J. Pablo Tomba, J.m. Carella, M. Isabel Gobernado-mitreAbstract:Abstract In this work, a systematic study of Physical Characterization on a series of commercial polyolefinic thermoplastic elastomers (TPEs), is reported. Formulations from different manufacturers, having a wide range of Shore hardness values (from A45 to D51), were examined using simple, inexpensive and standard laboratory methods. From this analysis, the TPE chemical composition and its relationship with hardness and tensile set—the key parameters that define the TPE performance in most of the applications—could be established. It was found that the strategy followed by the manufacturers to design TPEs is very similar. The EPDMs used for the different formulations look similar in ethylene content and thermal properties. Therefore, the TPE bulk modulus (or hardness) is mainly controlled by the PP content. Nice elastomeric behavior was observed only in grades with a dominant proportion of EPDM, in agreement with the deformation mechanism generally accepted for this type of materials. Grades with higher hardness values—and a dominant proportion of PP—showed a mechanical response corresponding to a toughened thermoplastic, even when these grades are marketed by the producers as “thermoplastic elastomers”. Differently from conventional crosslinked elastomers, where hardness and ability to recover from highly deformed states can be simultaneously controlled by changing the degree of crosslinking, the results of this work indicate that it is very difficult to increase TPE hardness without sacrificing elastomeric properties.
Maria Helena Ambrosio Zanin - One of the best experts on this subject based on the ideXlab platform.
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Physical Characterization of surface-modified liposomes by incorporation of gangliosides designed for immunotherapies
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004Co-Authors: Maria Helena Ambrosio Zanin, Iris L. Torriani, Ricardo De Lima Zollner, Maria Helena Andrade SantanaAbstract:Abstract Surface-modified liposomes with gangliosides prolong their half life in blood stream that associated to the poor immunogenic properties of gangliosides are potentially useful for applications as immunotherapic vehicles. The Physical characteristics of these biocolloids play an important role on their stability and exposition of the ganglioside antigens to the immunological system. The present work describes the Physical Characterization of liposomes incorporating a monosialoganglioside or a mixture of mono-, di- and trisialogangliosides. The liposomal matrix was composed of either dipalmitoylphosphatidylcholine and cholesterol, or in some preparations dihexadecylphosphate, which was added in order to provide a higher negative charge density on the liposome surface. Both types of liposomes were prepared by the dry phospholipids film hydration method and characterized by their phospholipid and ganglioside content, mean diameter, size distribution, morphology, membrane packing, lamellar structure and phase transition behavior.
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Physical Characterization of surface-modified liposomes by incorporation of gangliosides designed for immunotherapies
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004Co-Authors: Maria Helena Ambrosio Zanin, Iris L. Torriani, Ricardo L. Zollner, Maria Helena Andrade SantanaAbstract:Surface-modified liposomes with gangliosides prolong their half life in blood stream that associated to the poor immunogenic properties of gangliosides are potentially useful for applications as immunotherapic vehicles. The Physical characteristics of these biocolloids play an important role on their stability and exposition of the ganglioside antigens to the immunological system. The present work describes the Physical Characterization of liposomes incorporating a monosialoganglioside or a mixture of mono-, di- and trisialogangliosides. The liposomal matrix was composed of either dipalmitoylphosphatidylcholine and cholesterol, or in some preparations dihexadecylphosphate, which was added in order to provide a higher negative charge density on the liposome surface. Both types of liposomes were prepared by the dry phospholipids film hydration method and characterized by their phospholipid and ganglioside content, mean diameter, size distribution, morphology, membrane packing, lamellar structure and phase transition behavior. (C) 2004 Elsevier B.V. All rights reserved.2514169917518
Ying Yang - One of the best experts on this subject based on the ideXlab platform.
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Physical Characterization of a polyolefinic thermoplastic elastomer
Polymer, 1998Co-Authors: Ying Yang, Tsuneo Chiba, Hiromu Saito, Takashi InoueAbstract:Physical Characterization of a commercial polyolefinic thermoplastic elastomer (TPE), Santoprene®, was undertaken to understand the elastomeric nature of the two-phase material in which rubber particles are dispersed in a matrix of polypropylene (PP). Dynamic mechanical analysis showed that the PP matrix contains a small amount of rubber. PP crystal lamellae in rubber particles in a well-annealed sample were observed by transmission electron microscopy, suggesting that PP had been occluded in the rubber phase. Such partial phase-mixing may be caused by homogenization under high shear during dynamic vulcanization. Wide angle X-ray diffraction (WAXD) studies showed that PP crystallites in TPE are smaller than those in neat PP. That is, the occluded rubber in the PP matrix may play the role of impurity to render the smaller crystallites. By WAXD analysis on crystal orientation and its relaxation in stretching and releasing processes, it was shown that the smaller crystallites suffer less plastic deformation and, rather, play the role of tie points to provide the elastic properties of the PP matrix itself. About 40 wt% of process oil was found to be loaded on TPE; however, the oil seems to play a minor role in providing the elastomeric character.
