A novel self-assembled micelles based on stearic acid modified schizophyllan for efficient delivery of paclitaxel

Abstract

This study was aimed to design a novel amphiphilic carrier based on schizophyllan (SPG) exopolysacharide for drug delivery. Stearic acid (SA) was used for the esterification of SPG with two degrees of substitutions (SA-SPG0.5 and SA-SPG1). The H NMR and FTIR spectroscopies verified the succesfull esterification of SPG. The polymeric micelles easily self-assembled into nanomicelles by ultrasound method. Fluorescence spectroscopy showed that the critical micelle concentrations (CMCs) of SA-SPG0.5 and SA-SPG1 micelles were 0.068 mg/mL and 0.027 mg/mL, respectively. DLS analyses showed that nanomicelles were ranged from 156 to 175 nm. SEM and TEM images showed that nanomicelles were mostly spherical. Paclitaxel (PTX) as a drug model was successfully loaded into SA-SPG nanomicelles with three different drug/polymer weight ratios of 0.1, 0.2 and 0.3. The highest encapsulation efficiency (75 %) was obtained when the PTX/SA-SPG weight ratio was 0.1. The in vitro release of PTX from SA-SPG micelles represented the sustained release profile over 144 h. MTT assay showed that the PTX-loaded SA-SPG nanomicelles had the higher cytotoxicity against MCF-7 cells than free PTX. These results revealed that the synthesized SA-SPG nanomicelles had a promising potential as a new carrier for efficient delivery of hydrophobic drugs.

Keywords: Paclitaxel; Polymeric micelle; Schizophyllan; Stearic acid modified schizophyllan.