Synthesis and characterization of chitosan-conjugated arachidic acid for self-assembled nanoparticles as a new drug delivery carrier

Abstract

Chitosan oligosaccharide (CSO), a water–soluble low molecular weight chitosan, was hydrophobically modified with arachidic acid (AA), long chain fatty acid, through an EDC coupling reaction with different ratio of AA/CSO. Conjugation of synthesized chitosan oligosaccharide-conjugated arachidic acid (CSO-AA) was confirmed by FT-IR and 1H-NMR. The substitution ratios increased from 0.4 to 2.33 molar of AA substitution on CSO when the initial AA/CSO ratios increased during synthesis. Formation and characteristic of self-assembled nanoparticles of CSO-AA were determined by fluorescence spectroscopy, dynamic light scattering method and transmission electron microscopy. The critical micelle concentration (CMC) values decreased from 1.87 to 1.02 µg/ml with increasing the substitution ratio. The CSO-AAs formed spherical shape self-assembled nanoparticles with the particle sizes in the range of 65-77 nm depending on the substitution ratio. The zeta potentials were in the range of 2.74-16.15 mV. The results showed CSO-AA was successfully synthesized which could be applied for the preparation of self-assembled nanoparticles for hydrophobic drugs.