Amphotericin B-incorporated polymeric micelles composed of poly( d,l-lactide- co-glycolide)/dextran graft copolymer

Abstract

In this study, we prepared amphotericin B (AmpB)-encapsulated polymeric micelle of poly( d,l-lactide- co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer and characterized its physicochemical properties in vitro. The average particle size of AmpB-encpasulated DexLG polymeric micelles was around 30–150 nm while particle size of empty polymeric micelles was below 100 nm according to the copolymer composition. The morphology of AmpB-encapsulated polymeric micelle of DexLG copolymer was spherical shapes at transmission electron microscopy (TEM) observation. At 1H NMR study, specific peaks of AmpB and DexLG copolymer was obtained at DMSO but specific peaks characterized to AmpB and PLGA was disappeared at D 2O environment. These results indicated that AmpB was encapsulated into the micellar core of polymeric micelle. XRD results also support these results, indicating that specific crystal peaks of AmpB and broad peaks of DexLG copolymer were obtained but specific peaks of AmpB was disappeared at polymeric micelles while physical mixture of AmpB/empty polymeric micelles showed both specific peaks. Drug release rate was decreased according to the increase of drug contents and increase of PLGA component of DexLG copolymer. At the minimal inhibition concentration (MIC) study using Candida albicans, AmpB-encapsulated polymeric micelle showed almost similar effectives on the growth inhibition of microorganisms. These showed that AmpB-encapsulated polymeric micelle of DexLG copolymer can be considered to potential antifungal agent carriers.