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[EN] The conformational mobility in poly(ethyl methacrylate-co-hydrxyethyl acrylate) co-polymers was studied by dielectric relaxation spectroscopy, thermally stimulated depolarization currents and dynamic-mechanical experiments. The relaxation strength and the shape of the dielectric relaxation spectra of the homopolymer and co-polymer networks were analyzed using the Havriliak-Negami equation. The dependence of the relaxation strength on co-polymer composition and temperature was analyzed taking into account the merging of the main and the secondary relaxation processes. The shape of the epsilon" versus frequency plots led to the conclusion that the distribution of relaxation times was broader in the co-polymers with intermediate composition than in the homopolymers, a feature that can be explained by the inhomogeneity produced at molecular scale by the sequence distribution of the monomeric units along the chain. Master curves were built both for the elastic modulus and the mechanical loss tangent, and the temperature dependence of the relaxation times was deduced from the shift factors. The fit to the Vogel equation permitted the calculation of the strength parameter, which is higher in the co-polymers that the simple average of the values of the homopolymers, a feature that can be related to the broadness of the distribution of relaxation times. ; The authors are grateful for the support given by the Spanish Science and Technology Ministry through the MAT2003-05391-C03-01 project and by the Valencian Regional Government (Generalitat Valenciana) through the GRUPOS03/018 project. We would like to thank the R + D + i Linguistic Assistance Office at the Universidad Polite´cnica de Valencia for their help in revising this paper ; Gómez-Tejedor, JA.; Rodríguez Acosta, T.; Gómez Ribelles, JL.; Polizos, G.; Pissis, P. (2007). Poly(ethyl methacrylate-co-hydroxyethyl acrylate) random co-polymers: Dielectric and dynamic-mechanical characterization. Journal of Non-Crystalline Solids. 353(3):276-285. ...

[EN] Interactions between smooth muscle cells (SMCs) and biomaterials must not result in phenotype changes as this may generate uncontrolled multiplication processes and occlusions in vascular grafts. The aim of this study was to relate the hydrolytic stability and biocompatibility of polyurethanes (PUs) on SMCs. A higher polycaprolactone (PCL) concentration was found to improve the hydrolytic stability of the material and the adhesion of SMCs. A material with 5% polyethylene glycol, 90% PCL, and 5% pentaerythritol presented high cell viability and adhesion, suggesting a contractile phenotype in SMCs depending on the morphology. Nevertheless, all PUs retained their elastic modulus over 120 days, similar to the collagen of native arteries (similar to 10 MPa). Furthermore, aortic SMCs did not present toxicity (viability over 80%) and demonstrated adherence without any abnormal cell multiplication processes, which is ideal for the function to be fulfiled in situ in the vascular grafts. ; The research and publication were supported by the Universidad de La Sabana (ING-205-2018) and the Minister of Science, Technology, and Innovation of the Republic of Colombia, MINCIENCAS (Contract number 80740-186-2019). M. M-G. would like to thank the Universidad de La Sabana for the scholarship for her master's studies. S. A-A. would like to thank MINCIENCIAS for the doctoral training scholarship (Grant 727-2015). The authors are thankful to Professor Ericsson Coy Barrera and his staff at Nueva Granada Military University for the access to the VarioskanT LUX multimode microplate reader. J. A. S. acknowledges the financial support by MINECO through FIS2017-83295-P, MAT2015-71070-REDC, MAT2016-75586-C4-1/2/3-P and the Ramon y Cajal Fellowship (RYC-201517482). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. ; Morales-Gonzalez, M.; ...

3276 3285 35 23-24 ; S ; [EN] Interactions between smooth muscle cells (SMCs) and biomaterials must not result in phenotype changes as this may generate uncontrolled multiplication processes and occlusions in vascular grafts. The aim of this study was to relate the hydrolytic stability and biocompatibility of polyurethanes (PUs) on SMCs. A higher polycaprolactone (PCL) concentration was found to improve the hydrolytic stability of the material and the adhesion of SMCs. A material with 5% polyethylene glycol, 90% PCL, and 5% pentaerythritol presented high cell viability and adhesion, suggesting a contractile phenotype in SMCs depending on the morphology. Nevertheless, all PUs retained their elastic modulus over 120 days, similar to the collagen of native arteries (similar to 10 MPa). Furthermore, aortic SMCs did not present toxicity (viability over 80%) and demonstrated adherence without any abnormal cell multiplication processes, which is ideal for the function to be fulfiled in situ in the vascular grafts. The research and publication were supported by the Universidad de La Sabana (ING-205-2018) and the Minister of Science, Technology, and Innovation of the Republic of Colombia, MINCIENCAS (Contract number 80740-186-2019). M. M-G. would like to thank the Universidad de La Sabana for the scholarship for her master's studies. S. A-A. would like to thank MINCIENCIAS for the doctoral training scholarship (Grant 727-2015). The authors are thankful to Professor Ericsson Coy Barrera and his staff at Nueva Granada Military University for the access to the VarioskanT LUX multimode microplate reader. J. A. S. acknowledges the financial support by MINECO through FIS2017-83295-P, MAT2015-71070-REDC, MAT2016-75586-C4-1/2/3-P and the Ramon y Cajal Fellowship (RYC-201517482). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. ...