Linked Life Data

9801441

Source:http://linkedlifedata.com/resource/pubmed/id/9801441

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
1999-1-5
pubmed:abstractText
Poly(d,l-lactide-co-glycolide) (PLGA 37.5/25 and 25/50) biodegradable microparticles, which allow the locally delivery of a precise amount of a drug by stereotactic injection in the brain, were prepared by a W/O/W emulsion solvent evaporation/extraction method which had been previously optimized. The aim of this work was to study the influence of two formulation parameters (the presence of NaCl in the dispersing phase and the type of PLGA) on the NGF release profiles and NGF stability during microencapsulation. A honey-comb-like structure characterized the internal morphology of the microspheres. The initial burst was attributed to the rapid penetration of the release medium inside the matrix through a network of pores and to the desorption of weakly adsorbed protein from the surface of the internal cavities. The non-release fraction of the encapsulated protein observed after twelve weeks of incubation was accounted for firstly by the adsorption of the released protein on the degrading microparticles and secondly by the entanglement of the encapsulated protein in the polymer chains. The use of sodium chloride in the dispersing phase of the double emulsion markedly reduced the burst effect by making the microparticle morphology more compact. Unfortunately, it induced in parallel a pronounced NGF denaturation. Finally, it appeared that microparticles made from a hydrophilic uncapped PLGA 37.5/25 in the absence of salt, allowed the release of intact NGF at least during the first 24 h as determined by both ELISA and a PC12 cell-based bioassay.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0168-3659
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
56
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
175-87
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
NGF release from poly(D,L-lactide-co-glycolide) microspheres. Effect of some formulation parameters on encapsulated NGF stability.
pubmed:affiliation
UPRES EA 2169, Faculté de Pharmacie, 16 boulevard Daviers, 49100 Angers, France.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't