| 18395374 |
Taluja A, Bae YH: Role of a novel multifunctional excipient poly (ethylene glycol)-block-oligo (vinyl sulfadimethoxine) in controlled release of lysozyme from PLGA microspheres. Int J Pharm. 2008 Jun 24;358(1-2):50-9. Epub 2008 Feb 16.
This study investigated the effect of ion-pairing of anionic polyelectrolytes: our novel poly (ethylene glycol)-block-oligo (vinyl sulfadimethoxine) (PEG-OVSDM) and poly (ethylene glycol)-block-poly (l-aspartic acid) (PEG-PAA) with cationic lysozyme on retention of protein stability during emulsification. Soluble lysozyme recovery after exposure to the deleterious interface was 42-88% (when ion-paired with PEG-OVSDM, PEG-OVSDM concentration dependent) compared to only 30% for free lysozyme. PEG-OVSDM provided a higher stabilization of lysozyme than PEG-PAA (36-60%). Lysozyme when recovered in the aqueous phase and analyzed by chromatography, enzymatic assay, fluorescence, and mass spectrometry showed no significant physicochemical change when compared with a lysozyme standard. Lysozyme was incorporated into poly (lactide-co-glycolide) (PLGA) microspheres via the typical double emulsion method. Incorporation of lysozyme complexes led to a higher encapsulation efficiency and loading amount, and a lower incidence of insoluble lysozyme aggregates compared to the control microspheres containing lysozyme only. More significantly, ion-pairing was able to dramatically reduce the initial lysozyme release to 18% compared with 50% from control microspheres and provided an overall better control of protein release. PEG-PAA was less effective than PEG-OVSDM in controlling the release probably due to weaker interactions between this polyelectrolyte and lysozyme. Manipulation of such polyelectrolyte-protein complexation may play a role in protein-controlled delivery. |
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