Mapping microclimate pH distribution inside protein-encapsulated PLGA microspheres using confocal laser scanning microscopy.

ABSTRACT: The pH in the aqueous pores of poly(lactide-co-glycolide) (PLGA) matrix, also referred to as microclimate pH (μpH), is often uncontrolled, ranging from highly acidic to neutral pH range. The μpH distribution inside protein-encapsulated PLGA microspheres was quantitatively evaluated using confocal laser scanning microscopy. The fluorescent response of Lysosensor yellow/blue dextran used to map μpH in PLGA was influenced by the presence of encapsulated protein. The nonprotonated form of pyridyl group on the fluorescence probe at neutral pH was responsible for the interference, which was dependent on the type and concentration of protein. A method for correction of this interference based on estimating protein concentration inside the microspheres was established and validated. After correcti

SUBMITTER: Liu Y 

PROVIDER: S-EPMC3817562 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature