Preparation, characterization, and protein loading properties of N-acyl chitosan nanoparticles

Various N-acyl chitosans with propionyl-, hexanoyl-, nonanoyl-, lauroyl-, pentadecanoyl-, and stearoyl-groups were synthesized and self-aggregated N-acyl chitosan nanoparticles (CSNPs) were prepared by sonication. By the modification with N-acyl groups, CSNPs increased their hydrophobic character and changed its structural features to be more suitable as a delivery carrier. The mean diameters of bovine serum albumin (BSA)-loaded N-acyl CSNPs ranged from 138 to 551 nm. Uniform particle size distribution of BSA-loaded N-acyl CSNPs was observed. The protein loading efficiency of N-acyl CSNPs was about 94-95% with lower BSA concentration (0.1 mg/mL) and not significantly different with acyl chain length. With higher BSA concentration (1.0 mg/mL), however, the highest protein loading efficiency was observed with lauroyl and pentadecanoyl CSNPs. The results suggest that lauroyl and pentadecanoyl CSs are interesting candidates for protein delivery system.