Preparation and characterization of surfactant-modified chitosan micelles loaded with curcumin for their use as drug...

Surfactant-modified chitosan derivatives were prepared using Brij-35, a non-ionic surfactant, and low molecular weight chitosan (CS), with the aim of developing new nanocarriers of poor water-soluble compounds. First, surfactant Brij-35 was functionalized with succinic anhydride (SA) to give Brij-SA, which reacted with CS through an amidation reaction. The synthesized amphiphilic CS derivatives were characterized by proton nuclear magnetic resonance, infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. In addition, the particle size of CS-g-Brij-35 micelles was determined by dynamic light scattering, while the critical micelle concentration (CMC) was determined through different techniques, including surface tension, conductivity, and pH. Afterward, CS-g-Brij-35 micelles were loaded with curcumin and the release profiles were studied at two pH values (7.4 and 5.0). Results showed that the grafting of surfactant onto CS depended on the molar ratio of Brij-35:CS, obtaining values from 3 to 21 %. The CS-g-Brij-35 micelles showed an average size of ~225 nm and CMC value of ~0.1 mg/mL. Finally, a sustained release during the first 10 h was observed with an increase of the release percentage at pH 5.0, which could make them suitable as nanocarriers of hydrophobic drugs.