The acute thrombogenicity of a new polyurethane urea graft has been compared with polytetrafluoroethylene (PTFE) grafts using labelled homologous platelets in the carotid arteries of sheep in a low-flow model. There was no difference in patency. Thrombus weight and thrombus free surface were the same in both types of graft after 4 h. The accumulation of homologous 32P platelets was measured at the 2 anastomoses and at a midgraft position. At no point was there any statistically significant difference between the 2 grafts, but the activity was always somewhat higher in the polyurethane grafts. Although more compliant, in this study polyurethane urea grafts behaved much like PTFE ones.
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http://dx.doi.org/10.1159/000128674 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China.
The ongoing soft actuation has accentuated the demand for dielectric elastomers (DEs) capable of large deformation to replace the traditional rigid mechanical apparatus. However, the low actuation strain of DEs considerably limits their practical applications. This work developed high-performance polyurethane-urea (PUU) elastomers featuring large actuation strains utilizing an approach of kinetic control over the microphase separation structure during the fabrication process.
View Article and Find Full Text PDFACS Appl Polym Mater
December 2024
Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6DX, United Kingdom.
Adv Mater
December 2024
Engineering Research Center of Energy Storage Materials and Devices Ministry of Education, School of Chemistry, Xi'an Jiaotong University, Xi'an, 710049, China.
Hydrogels with mechanical performances similar to load-bearing tissues are in demand for in vivo applications. In this work, inspired by the self-assembly behavior of amphiphilic polymers, polyurethane-based tough hydrogels with a multiple hydrogen-bond interlocked bicontinuous phase structure through in situ water-induced microphase separation strategy are developed, in which poly(ethylene glycol)-based polyurethane (PEG-PU, hydrophilic) and poly(ε-caprolactone)-based polyurethane (PCL-PU, hydrophobic) are blended to form dry films followed by water swelling. A multiple hydrogen bonding factor, imidazolidinyl urea, is introduced into the synthesis of the two polyurethanes, and the formation of multiple hydrogen bonds between PEG-PU and PCL-PU can promote homogeneous microphase separation for the construction of bicontinuous phase structures in the hydrogel network, by which the hydrogel features break strength of 12.
View Article and Find Full Text PDFInt J Pharm
December 2024
Department of Biological, Chemical, and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, Palermo, Italy; Istituto per la Ricerca e Innovazione Biomedica (IRIB), CNR, Via Ugo La Malfa, 153, 90146, Palermo, Italy. Electronic address:
Despite advancements in cancer treatments, therapies frequently exhibit high cytotoxicity, and surgery remains the predominant method for treating most solid tumors, often with limited success in preventing post-surgical recurrence. Implantable biomaterials, designed to release drugs at a localised site in response to specific stimuli, represent a promising approach for enhancing tumour therapy. In this study, a redox-responsive glutathione extended polyurethane urea (PolyCEGS) was used to produce paclitaxel (PTX) and gold nanorods (AuNRs) loaded electrospun membranes for combined redox/near-infrared (NIR) light-responsive release chemotherapy and hyperthermic effect.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
Encapsulation of volatile organic compounds (VOCs) that could evaporate at a defined rate is of immense interest for application in emission reference materials (ERMs). Polyurethane/polyurea microcapsules with various VOC active ingredients (limonene, pinene, and toluene) were successfully produced by interfacial polymerization with Shirasu porous glass membrane emulsification in a size range between 10 and 50 μm. The effect of surfactant, VOC, monomer(s) type, and ratio has a great effect on the formulation process and morphology of capsules.
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