Linked Life Data

2394759

Source:http://linkedlifedata.com/resource/pubmed/id/2394759

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1990-10-9
pubmed:abstractText
The in vitro degradation of glycine-DL-lactic acid copolymers was studied as a function of the composition. These polydepsipeptides were prepared by ring-opening copolymerization of 6-methyl-2,5-morpholinedione and DL-lactide. The degradation of discs of the copolymers was performed in a phosphate buffer at pH 7.4 and 37 degrees C. The decrease in molecular weight and weight was determined until complete weight loss had occurred. Poly(DL-lactide) was used as a reference material. All (co)-polymers show an immediate decrease in molecular weight, whereas the weight remains almost unchanged during a longer period of time. Decrease in weight started earlier as the glycine content of the co-polymer increased. The lactic acid content of the residual material increased during the weight loss showing a higher solubility of polymer fragments with a relatively high content of glycine residues. From the hydrolysis constants it was concluded that the degradation was best described by hydrolysis of ester bonds via a bulk erosion process, autocatalyzed by the generated carboxylic acid end groups. The rate constants varied from 4-7 X 10(-2) (day-1) for all (co)polymers. All (co)polymers show an increase in the molecular weight distribution upon weight loss.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9304
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1005-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
In vitro degradation of glycine/DL-lactic acid copolymers.
pubmed:affiliation
Department of Chemical Technology, Twente University, Enschede, The Netherlands.
pubmed:publicationType
Journal Article, In Vitro