Self-assembled nanomicelles of damnacanthal-loaded amphiphilic modified chitosan: Preparation, characterization and cytotoxicity study

Abstract

Damnacanthal (Dam) is a phytochemical with many pharmacological properties including anticancer activity. However, its hydrophobicity, poor bioavailability and stability limit its application in many biological approaches. In this study, Dam nanomicelles as an emerging platform were developed to overcome limitations. The deoxycholic and poly(ethylene glycol) methyl ether grafted chitosan (DCA-CS-mPEG) was synthesized and characterized by FTIR and ¹H NMR and the degree of substitution (DS) was determined by elemental analysis (EA). This polymer formed self-assembled micelles with a core-shell structure and a critical micelle concentration (CMC) of 37.2μg/mL. Dam-loaded polymeric micelles were prepared by dialysis method and characterized by DLS, TEM, FTIR, DSC and HPLC. The mean particle size of Dam-loaded micelles was about 200nm with spherical shape. The drug entrapment efficiency was up to 57.7%. FTIR and DSC analysis revealed that Dam was entrapped in the micelles in the amorphous state. The in vitro release profiles of Dam from micelles were sustained release and pH-sensitive behavior. Cytotoxic studies exhibited the comparable efficacy and safety of this delivery system. Overall these results indicate the possible utilization of DCA-CS-mPEG micelles as a promising carrier for hydrophobic compounds like Dam.

Keywords: Chitosan; Damnacanthal; Drug delivery; Nanomicelles; Self-assembled nanoparticles.