Linked Life Data

12635770

Source:http://linkedlifedata.com/resource/pubmed/id/12635770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-3-14
pubmed:abstractText
Poly(lactide-co-ethylphosphate)s, a new class of linear phosphorus-containing copolymers made by chain-extending low-molecular-weight polylactide prepolymers with ethyl dichlorophosphate, were investigated for their in vitro and in vivo degradation mechanism and kinetics. Microspheres made from poly(lactide-co-ethylphosphate) were studied under both accelerated and normal in vitro degradation conditions. Gel permeation chromatography (GPC), 1H- and 31P-NMR, weight loss measurements, and differential scanning calorimetry (DSC) techniques were used to characterize the change of molecular weight (M(w)), chemical composition, and glass transition temperature (T(g)) of the degrading polymers. The results indicated that the copolymers degraded in a two-stage fashion, with cleavage of the phosphate-lactide linkages contributing mostly to the initial more rapid degradation phase and cleavage of the lactide-lactide bonds being responsible for the slower latter stage degradation. The decrease in the copolymer M(w) was accompanied by a continuous mass loss. Results from the accelerated degradation studies confirmed that the copolymers degraded into various monomers of the copolymers, which were non-toxic and biocompatible. A two-stage hydrolysis pathway was thus proposed to explain the degradation behavior of the copolymers. In vivo degradation studies performed in mice demonstrated a good in vitro and in vivo correlation for the degradation rates. In vivo clearance of the polymer was faster and without any lag phase. These copolymers are potentially advantageous for drug delivery and other biomedical applications where rapid clearance of the polymer carrier and repeated dosing capability are essential to the success of the treatment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0920-5063
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45-61
pubmed:dateRevised
2008-2-20
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
In vitro and in vivo degradation studies of a novel linear copolymer of lactide and ethylphosphate.
pubmed:affiliation
Guilford Pharmaceuticals Inc., 6611 Tributary Street, Baltimore, MD 21224, USA.
pubmed:publicationType
Journal Article