Document Detail


A novel potentiometric method for the determination of real crosslinking ratio of poly(aspartic acid) gels.
MedLine Citation:
PMID:  19761876     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In order to obtain nontoxic functional polymer gels for biomedical applications, chemically crosslinked poly(aspartic acid) gels have been prepared using 1,4-diaminobutane as crosslinker. The presence of COOH and amino groups on the network chains renders these gels pH sensitive. Due to the specific hydrophobic-hydrophilic balance, these gels show a significant volume transition at a well-defined pH close to the pK value of uncrosslinked poly(aspartic acid). Since the magnitude of volume change critically depends on the degree of crosslinking, it is an important task to determine the topological characteristics of these networks. A novel method based on potentiometric acid-base titration has been developed to assess the crosslinking ratio, excluding physical crosslinks and entanglements. It turned out that only 25% of all crosslinker molecules forms real crosslinks between the poly(aspartic acid) chains; the rest react with one of its functional groups and forms short pendant side chains. At a nominal crosslinking ratio of 0.1, the number average molecular mass between crosslinks is found to be M(c) = 2300.
Authors:
Vikt?ria Torma; Tam?s Gyenes; Zolt?n Szak?cs; Mikl?s Zr?nyi
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-09-15
Journal Detail:
Title:  Acta biomaterialia     Volume:  6     ISSN:  1878-7568     ISO Abbreviation:  Acta Biomater     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-02-01     Completed Date:  2010-03-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101233144     Medline TA:  Acta Biomater     Country:  England    
Other Details:
Languages:  eng     Pagination:  1186-90     Citation Subset:  IM    
Copyright Information:
Copyright 2010. Published by Elsevier Ltd.
Affiliation:
Department of Pharmaceutics, Faculty of Pharmacy, Semmelweis University, Hogyes Endre u. 7, H-1092 Budapest, Hungary. viki.torma@gmail.com
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MeSH Terms
Descriptor/Qualifier:
Biocompatible Materials / chemistry*
Cross-Linking Reagents / chemistry*
Electrochemistry / methods*
Gels / chemistry*
Materials Testing / methods*
Peptides / chemistry*
Chemical
Reg. No./Substance:
0/Biocompatible Materials; 0/Cross-Linking Reagents; 0/Gels; 0/Peptides; 26063-13-8/polyaspartate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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