Ethylenediamino bridged bis(β-cyclodextrin)/ poly(DL-lactic-co-glycolic acid) nanoparticles prepared by modified double emulsion method: effect of polyvinyl alcohol on nanoparticle properties.
writer：H. Gao, Y.-N. Wang, Y.-G. Fan, J.-B. Ma.
keywords：double emulsion, cyclodextrin, polylactic acid, polyvinyl alcohol
source：期刊
specific source：J Appl Polym Sci, 2008; 107: 571–576.
Issue time：2007年
This study continues long-standing efforts to develop protein delivery systems based on cyclodextrinconjugated polyester in our laboratory. The crude products
of ethylenediamino bridged bis(b-cyclodextrin)-conjugated oly(DL-lactic-co-glycolic acid) were used in this study to take full use of unreacted reactant. With bovine serum albumin (BSA) as a model protein, the encapsulation effects (the encapsulation efficiency and particle size) of nanoparticles were similar to those of using pure conjugated products. Besides, a water-in-oil-in-water emulsification
technique was conveniently modified. By adding polyvinyl alcohol (PVA) in the internal aqueous phase, a more stabilized emulsion was formed. Consequently, less PVA ( 0.05%) was needed in the outer aqueous phase and less PVA (0.14 g/g nanoparticles) remained in the nanoparticles.
This modification resulted in improved encapsulation efficiency ( 89–94%) of BSA and an enlarged particle size (340–390 nm). Furthermore, the burst release of BSA
at the 1st day was less pronounced (7–12% of the encapsulated amount) than that of nanoparticles with no PVA added in the internal aqueous phase. Degradation studies using transmission electron microscope and gel permeation
chromatography suggested that the mechanism for protein release was mainly through nanoparticles erosion.