The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
L. Chan-Chan - One of the best experts on this subject based on the ideXlab platform.
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Characterization of model compounds and poly(amide-urea) urethanes based on amino acids by FTIR, NMR and other analytical techniques
European Polymer Journal, 2017Co-Authors: L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Gerardo González-garcía, F. Hernández-sánchez, Ángel Marcos-fernández, Juan V. Cauich-rodríguezAbstract:Abstract The synthesis of novel polyurethanes is a subject of increasing interest, especially those that involve biologically active molecules. Generally, the reports on the synthesis of segmented polyurethanes using modified amino acids as chain extenders assume that the reaction occurs due to functionalities (OH and NH2) of the last compounds. However, few works really prove the reaction takes place with unmodified amino acids. In this work, spectroscopic techniques such as 1H, 13C, and 1H-1H COSY NMR and FTIR were used to chemical characterization of poly(urea-amide) urethanes synthesized from polycaprolactone diol (PCL diol 530), 4,4′-methylene-bis(Cyclohexyl Isocyanate) (H12MDI), and amino acids such as l -arginine, glycine or l -aspartic acid as chain extenders. In addition, model compounds (without PCL diol) were analyzed to confirm reaction of amino acids via urea and amide formation. Additionally, the polymers exhibited different physicochemical and mechanical properties depending on the chain extender used. These results suggest that unmodified amino acids can be used as chain extenders in the synthesis of poly(amide-urea) urethanes for biomedical applications.
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Human mesenchymal stem cell behavior on segmented polyurethanes prepared with biologically active chain extenders
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Taylor E Kavanaugh, L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Andrés J. García, Amy Y Clark, Maricela Ramírez-saldaña, Fernando Hernández-sánchez, Juan V. Cauich-rodríguezAbstract:The development of elastomeric, bioresorbable and biocompatible segmented polyurethanes (SPUs) for use in tissue-engineering applications has attracted considerable interest because of the existing need of mechanically tunable scaffolds for regeneration of different tissues, but the incorporation of osteoinductive molecules into SPUs has been limited. In this study, SPUs were synthesized from poly (ε-caprolactone)diol, 4,4′-methylene bis(Cyclohexyl Isocyanate) using biologically active compounds such as ascorbic acid, l -glutamine, β-glycerol phosphate, and dexamethasone as chain extenders. Fourier transform infrared spectroscopy (FTIR) revealed the formation of both urethanes and urea linkages while differential scanning calorimetry, dynamic mechanical analysis, X-ray diffraction and mechanical testing showed that these polyurethanes were semi-crystalline polymers exhibiting high deformations. Cytocompatibility studies showed that only SPUs containing β-glycerol phosphate supported human mesenchymal stem cell adhesion, growth, and osteogenic differentiation, rendering them potentially suitable for bone tissue regeneration, whereas other SPUs failed to support either cell growth or osteogenic differentiation, or both. This study demonstrates that modification of SPUs with osteogenic compounds can lead to new cytocompatible polymers for regenerative medicine applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4′-methylene bis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain extend
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, José Parra, Roi Rath, R. Vargas-coronado, José M. Cervantes-uc, Juan V. Cauich-rodríguez, Ea Phelps, Andrés J. García, J San Román Del Barrio, Yahye MerhiAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4′-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4'-methylenebis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain exte
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, J. S. R. del Barrio, José Parra, Roi Rath, R. Vargas-coronado, Elizabeth Phelps, Jorge Cervantes, Alejandro Garcia, Yahye Merhi, Maryam TabrizianAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4'-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
R. Vargas-coronado - One of the best experts on this subject based on the ideXlab platform.
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Characterization of model compounds and poly(amide-urea) urethanes based on amino acids by FTIR, NMR and other analytical techniques
European Polymer Journal, 2017Co-Authors: L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Gerardo González-garcía, F. Hernández-sánchez, Ángel Marcos-fernández, Juan V. Cauich-rodríguezAbstract:Abstract The synthesis of novel polyurethanes is a subject of increasing interest, especially those that involve biologically active molecules. Generally, the reports on the synthesis of segmented polyurethanes using modified amino acids as chain extenders assume that the reaction occurs due to functionalities (OH and NH2) of the last compounds. However, few works really prove the reaction takes place with unmodified amino acids. In this work, spectroscopic techniques such as 1H, 13C, and 1H-1H COSY NMR and FTIR were used to chemical characterization of poly(urea-amide) urethanes synthesized from polycaprolactone diol (PCL diol 530), 4,4′-methylene-bis(Cyclohexyl Isocyanate) (H12MDI), and amino acids such as l -arginine, glycine or l -aspartic acid as chain extenders. In addition, model compounds (without PCL diol) were analyzed to confirm reaction of amino acids via urea and amide formation. Additionally, the polymers exhibited different physicochemical and mechanical properties depending on the chain extender used. These results suggest that unmodified amino acids can be used as chain extenders in the synthesis of poly(amide-urea) urethanes for biomedical applications.
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Human mesenchymal stem cell behavior on segmented polyurethanes prepared with biologically active chain extenders
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Taylor E Kavanaugh, L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Andrés J. García, Amy Y Clark, Maricela Ramírez-saldaña, Fernando Hernández-sánchez, Juan V. Cauich-rodríguezAbstract:The development of elastomeric, bioresorbable and biocompatible segmented polyurethanes (SPUs) for use in tissue-engineering applications has attracted considerable interest because of the existing need of mechanically tunable scaffolds for regeneration of different tissues, but the incorporation of osteoinductive molecules into SPUs has been limited. In this study, SPUs were synthesized from poly (ε-caprolactone)diol, 4,4′-methylene bis(Cyclohexyl Isocyanate) using biologically active compounds such as ascorbic acid, l -glutamine, β-glycerol phosphate, and dexamethasone as chain extenders. Fourier transform infrared spectroscopy (FTIR) revealed the formation of both urethanes and urea linkages while differential scanning calorimetry, dynamic mechanical analysis, X-ray diffraction and mechanical testing showed that these polyurethanes were semi-crystalline polymers exhibiting high deformations. Cytocompatibility studies showed that only SPUs containing β-glycerol phosphate supported human mesenchymal stem cell adhesion, growth, and osteogenic differentiation, rendering them potentially suitable for bone tissue regeneration, whereas other SPUs failed to support either cell growth or osteogenic differentiation, or both. This study demonstrates that modification of SPUs with osteogenic compounds can lead to new cytocompatible polymers for regenerative medicine applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4′-methylene bis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain extend
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, José Parra, Roi Rath, R. Vargas-coronado, José M. Cervantes-uc, Juan V. Cauich-rodríguez, Ea Phelps, Andrés J. García, J San Román Del Barrio, Yahye MerhiAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4′-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4'-methylenebis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain exte
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, J. S. R. del Barrio, José Parra, Roi Rath, R. Vargas-coronado, Elizabeth Phelps, Jorge Cervantes, Alejandro Garcia, Yahye Merhi, Maryam TabrizianAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4'-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
Yahye Merhi - One of the best experts on this subject based on the ideXlab platform.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4′-methylene bis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain extend
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, José Parra, Roi Rath, R. Vargas-coronado, José M. Cervantes-uc, Juan V. Cauich-rodríguez, Ea Phelps, Andrés J. García, J San Román Del Barrio, Yahye MerhiAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4′-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4'-methylenebis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain exte
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, J. S. R. del Barrio, José Parra, Roi Rath, R. Vargas-coronado, Elizabeth Phelps, Jorge Cervantes, Alejandro Garcia, Yahye Merhi, Maryam TabrizianAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4'-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
Juan V. Cauich-rodríguez - One of the best experts on this subject based on the ideXlab platform.
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Characterization of model compounds and poly(amide-urea) urethanes based on amino acids by FTIR, NMR and other analytical techniques
European Polymer Journal, 2017Co-Authors: L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Gerardo González-garcía, F. Hernández-sánchez, Ángel Marcos-fernández, Juan V. Cauich-rodríguezAbstract:Abstract The synthesis of novel polyurethanes is a subject of increasing interest, especially those that involve biologically active molecules. Generally, the reports on the synthesis of segmented polyurethanes using modified amino acids as chain extenders assume that the reaction occurs due to functionalities (OH and NH2) of the last compounds. However, few works really prove the reaction takes place with unmodified amino acids. In this work, spectroscopic techniques such as 1H, 13C, and 1H-1H COSY NMR and FTIR were used to chemical characterization of poly(urea-amide) urethanes synthesized from polycaprolactone diol (PCL diol 530), 4,4′-methylene-bis(Cyclohexyl Isocyanate) (H12MDI), and amino acids such as l -arginine, glycine or l -aspartic acid as chain extenders. In addition, model compounds (without PCL diol) were analyzed to confirm reaction of amino acids via urea and amide formation. Additionally, the polymers exhibited different physicochemical and mechanical properties depending on the chain extender used. These results suggest that unmodified amino acids can be used as chain extenders in the synthesis of poly(amide-urea) urethanes for biomedical applications.
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Human mesenchymal stem cell behavior on segmented polyurethanes prepared with biologically active chain extenders
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Taylor E Kavanaugh, L. Chan-Chan, R. Vargas-coronado, José M. Cervantes-uc, Andrés J. García, Amy Y Clark, Maricela Ramírez-saldaña, Fernando Hernández-sánchez, Juan V. Cauich-rodríguezAbstract:The development of elastomeric, bioresorbable and biocompatible segmented polyurethanes (SPUs) for use in tissue-engineering applications has attracted considerable interest because of the existing need of mechanically tunable scaffolds for regeneration of different tissues, but the incorporation of osteoinductive molecules into SPUs has been limited. In this study, SPUs were synthesized from poly (ε-caprolactone)diol, 4,4′-methylene bis(Cyclohexyl Isocyanate) using biologically active compounds such as ascorbic acid, l -glutamine, β-glycerol phosphate, and dexamethasone as chain extenders. Fourier transform infrared spectroscopy (FTIR) revealed the formation of both urethanes and urea linkages while differential scanning calorimetry, dynamic mechanical analysis, X-ray diffraction and mechanical testing showed that these polyurethanes were semi-crystalline polymers exhibiting high deformations. Cytocompatibility studies showed that only SPUs containing β-glycerol phosphate supported human mesenchymal stem cell adhesion, growth, and osteogenic differentiation, rendering them potentially suitable for bone tissue regeneration, whereas other SPUs failed to support either cell growth or osteogenic differentiation, or both. This study demonstrates that modification of SPUs with osteogenic compounds can lead to new cytocompatible polymers for regenerative medicine applications.
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Platelet adhesion and human umbilical vein endothelial cell cytocompatibility of biodegradable segmented polyurethanes prepared with 4,4′-methylene bis(Cyclohexyl Isocyanate), poly(caprolactone) diol and butanediol or dithioerythritol as chain extend
Journal of Biomaterials Applications, 2012Co-Authors: L. Chan-Chan, José Parra, Roi Rath, R. Vargas-coronado, José M. Cervantes-uc, Juan V. Cauich-rodríguez, Ea Phelps, Andrés J. García, J San Román Del Barrio, Yahye MerhiAbstract:Biodegradable segmented polyurethanes were prepared with poly(caprolactone) diol as a soft segment, 4,4′-methylene bis(Cyclohexyl Isocyanate) (HMDI) and either butanediol or dithioerythritol as chain extenders. Platelet adhesion was similar in all segmented polyurethanes studied and not different from Tecoflex® although an early stage of activation was observed on biodegradable segmented polyurethane prepared with dithioerythritol. Relative viability was higher than 80% on human umbilical vein endothelial cells in contact with biodegradable segmented polyurethane extracts after 1, 2 and 7 days. Furthermore, both biodegradable segmented polyurethane materials supported human umbilical vein endothelial cell adhesion, spreading, and viability similar to Tecoflex® medical-grade polyurethane. These biodegradable segmented polyurethanes represent promising materials for cardiovascular applications.
Michael R. Buchmeiser - One of the best experts on this subject based on the ideXlab platform.
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A Spirocyclic Parabanic Acid Masked N‐Heterocyclic Carbene as Thermally Latent Pre‐Catalyst for Polyamide 6 Synthesis and Epoxide Curing
Macromolecular Rapid Communications, 2020Co-Authors: Hagen J. Altmann, Wolfgang Frey, Michael R. BuchmeiserAbstract:1,3-Dicyclcohexyl-6,9-dimethyl-1,3,6,9-tetraazaspiro[4.4]non-7-ene-2,4-dione, a spirocyclic parabanic acid derivative of N,N-dimethylimidazole, is used as thermally latent, protected N-heterocyclic carbene (NHC) in polymerizing anhydride-cured epoxide resins, and azepan-2-one, respectively. The protected carbene is synthesized from 1,3-dimethylimidazolium-2-carboxylate in the presence of two equivalents of Cyclohexyl Isocyanate. In the synthesis of epoxide resin thermosets, this class of latent NHC allows the production of fast and fully cured materials with high crosslinking content. Fast and complete conversion is found in the anionic ring opening polymerization (AROP) of azepan-2-one (e-caprolactam, CLA) with and without additional activators.
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a spirocyclic parabanic acid masked n heterocyclic carbene as thermally latent pre catalyst for polyamide 6 synthesis and epoxide curing
Macromolecular Rapid Communications, 2020Co-Authors: Hagen J. Altmann, Wolfgang Frey, Michael R. BuchmeiserAbstract:1,3-Dicyclcohexyl-6,9-dimethyl-1,3,6,9-tetraazaspiro[4.4]non-7-ene-2,4-dione, a spirocyclic parabanic acid derivative of N,N-dimethylimidazole, is used as thermally latent, protected N-heterocyclic carbene (NHC) in polymerizing anhydride-cured epoxide resins, and azepan-2-one, respectively. The protected carbene is synthesized from 1,3-dimethylimidazolium-2-carboxylate in the presence of two equivalents of Cyclohexyl Isocyanate. In the synthesis of epoxide resin thermosets, this class of latent NHC allows the production of fast and fully cured materials with high crosslinking content. Fast and complete conversion is found in the anionic ring opening polymerization (AROP) of azepan-2-one (e-caprolactam, CLA) with and without additional activators.
