Linked Life Data

18672929

Source:http://linkedlifedata.com/resource/pubmed/id/18672929

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2008-9-8
pubmed:abstractText
New thermothickening copolymers were synthesized by grafting responsive poly(ethylene oxide-co-propylene oxide) [PEPO] onto three different polysaccharide backbones: carboxymethylcellulose [CMC], alginate [ALG], and carboxylated dextran [DEX]. The coupling reaction between carboxylic groups of biopolymers and the terminal amine of PEPO was activated at low temperature ( T < 10 degrees C) in water by using carbodiimide and N-hydroxysuccinimide. In these conditions it was shown that the formation of amide bonds strongly depends on the concentration of reactive groups, which is limited by the viscosity of the polymer sample. While a full conversion was obtained for the low molecular weight dextran, the efficiency of grafting remains low (between 30 to 40%) for CMC and alginate, which give a solution of high viscosity even at low concentration. When studied in the semidilute regime, all the copolymer solutions clearly exhibit thermothickening behavior with a large and reversible increase of viscosity upon heating. The association temperature and the gelation threshold were shown to depend on polymer concentration as it is expected from the phase diagram of PEPO precursor. Similarly, the influence of added salt on PEPO solubility in water has been used to control the self-assembling behavior of copolymer formulations. The relative comparison between the three copolymers reveals that the amplitude of the viscosity jump induced by heating mainly depends on the proportion of responsive material inside the macromolecular architecture rather than the dimensions of the main chain. The high increase of viscosity, which can reach several orders of magnitude between 20 degrees C and body temperature, clearly demonstrates the potentiality of these copolymers in biomedical applications like injectable gels for tissue engineering.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Alginates, http://linkedlifedata.com/resource/pubmed/chemical/Amines, http://linkedlifedata.com/resource/pubmed/chemical/Biopolymers, http://linkedlifedata.com/resource/pubmed/chemical/Carbodiimides, http://linkedlifedata.com/resource/pubmed/chemical/Carboxymethylcellulose Sodium, http://linkedlifedata.com/resource/pubmed/chemical/Dextrans, http://linkedlifedata.com/resource/pubmed/chemical/Glucuronic Acid, http://linkedlifedata.com/resource/pubmed/chemical/Hexuronic Acids, http://linkedlifedata.com/resource/pubmed/chemical/N-hydroxysuccinimide, http://linkedlifedata.com/resource/pubmed/chemical/Polyethylenes, http://linkedlifedata.com/resource/pubmed/chemical/Polypropylenes, http://linkedlifedata.com/resource/pubmed/chemical/Solutions, http://linkedlifedata.com/resource/pubmed/chemical/Succinimides, http://linkedlifedata.com/resource/pubmed/chemical/UCON 50-HB-5100, http://linkedlifedata.com/resource/pubmed/chemical/Water, http://linkedlifedata.com/resource/pubmed/chemical/alginic acid
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1526-4602
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2419-29
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Synthesis and rheological properties of responsive thickeners based on polysaccharide architectures.
pubmed:affiliation
Physico-Chimie des Polymères et des Milieux Dispersés, UMR 7615, UPMC-CNRS-ESPCI, 10 rue Vauquelin, 75005 Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't