Linked Life Data

15468199

Source:http://linkedlifedata.com/resource/pubmed/id/15468199

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-10-6
pubmed:abstractText
Supramolecular hydrogels have been prepared on the basis of polymer inclusion complex (PIC) formation between poly(ethylene glycol) (PEG)-modified chitosans and alpha-cyclodextrin (alpha-CD). A series of PEG-modified chitosans were synthesized by coupling reactions between chitosan and monocarboxylated PEG using water-soluble carbodiimide (EDC) as coupling agent. With simple mixing, the resultant supramolecular assembly of the polymers and alpha-CD molecules led to hydrogel formation in aqueous media. The supramolecular structure of the PIC hydrogels was confirmed by differential scanning calorimetry (DSC), X-ray diffraction, and (13)C cross-polarized/magic-angle spinning (CP/MAS) NMR characterization. The PEG side-chains on the chitosan backbones were found to form inclusion complexes (ICs) with alpha-CD molecules, resulting in the formation of channel-type crystalline micro-domains. The IC domains play an important role in holding together hydrated chitosan chains as physical junctions. The gelation property was affected by several factors including the PEG content in the polymers, the solution concentration, the mixing ratio of host and guest molecules, temperature, pH, etc. All the hydrogels in acidic conditions exhibited thermo-reversible gel-sol transitions under appropriate conditions of mixing ratio and PEG content in the mixing process. The transitions were induced by supramolecular association and dissociation. These supramolecular hydrogels were found to have phase-separated structures that consist of hydrophobic crystalline PIC domains, which were formed by the host-guest interaction between alpha-CD and PEG, and hydrated chitosan matrices below the pK(a).The formation of inclusion complexes between alpha-cyclodextrin and PEG-modified chitosan leads to the formation of hydrogels that can undergo thermo-reversible supramolecular dissociation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1616-5187
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
92-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Supramolecular hydrogel formation based on inclusion complexation between poly(ethylene glycol)-modified chitosan and alpha-cyclodextrin.
pubmed:affiliation
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Ishikawa 923-1292, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't