Document Detail


The degradative resistance of polyhedral oligomeric silsesquioxane nanocore integrated polyurethanes: an in vitro study.
MedLine Citation:
PMID:  16253324     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Polymer biostability is one of the critical parameters by which these materials are selected for use as biomedical devices. This is the major rationale for the use of polymers which are highly crystalline and stiff namely expanded polytetrafluoroethylene (ePTFE) and Dacron in particular, as arterial bypass grafts. While this is immaterial in high-flow states, it becomes critically important at lower flows with a greater need for more compliant vessels. Polyurethanes being one of the most compliant polymers known are as such, the natural choice to build such constructs. However, concerns regarding their resistance to degradation have limited their use as vascular prostheses and in order to augment their strength, herein a novel polyhedral oligomeric silsesquioxane integrated poly(carbonate-urea)urethane (POSS-PCU) nanocomposite was synthesised by our group. In the following series of experiments, the POSS-PCU nanocomposite samples were exposed to accelerated degradative solutions, in an 'in-house' established model in vitro for up to 70 days before being subjected to infra-red spectroscopy, scanning electron microscopy, stress-strain studies and differential scanning calorimetry. Our results demonstrate that these silsesquioxane nanocores shield the soft segment(s) of the polyurethane, responsible for its compliance and elasticity from all forms of degradation, principally oxidation and hydrolysis. These nanocomposites hence provide an optimal method by which these polymers may be strengthened whilst maintaining their elasticity, making them ideal as vascular prostheses particularly at low flow states.
Authors:
Ruben Y Kannan; Henryk J Salacinski; Marianne Odlyha; Peter E Butler; Alexander M Seifalian
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-10-25
Journal Detail:
Title:  Biomaterials     Volume:  27     ISSN:  0142-9612     ISO Abbreviation:  Biomaterials     Publication Date:  2006 Mar 
Date Detail:
Created Date:  2005-12-12     Completed Date:  2006-04-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8100316     Medline TA:  Biomaterials     Country:  England    
Other Details:
Languages:  eng     Pagination:  1971-9     Citation Subset:  IM    
Affiliation:
Biomaterials & Tissue Engineering Centre (BTEC), Academic Division of Surgical and Interventional Sciences, University College London, Rowland Hill, Hampstead, London NW3 2PF, UK.
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MeSH Terms
Descriptor/Qualifier:
Biocompatible Materials / chemistry*
Biodegradation, Environmental
Blood Vessel Prosthesis*
Elasticity
Materials Testing
Nanostructures / chemistry
Polymers / chemistry*
Polyurethanes / chemistry*
Siloxanes / chemistry*
Spectroscopy, Fourier Transform Infrared
Stress, Mechanical
Surface Properties
Temperature
Chemical
Reg. No./Substance:
0/Biocompatible Materials; 0/Polymers; 0/Polyurethanes; 0/Siloxanes; 0/poly(carbonate urea) urethane

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