• drug delivery systems;
  • morphology;
  • nanotechnology


The objective of this work was to characterize a novel quaternary chitosan derivative [O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC)] nanoparticle system. O-HTCC nanoparticles were prepared with a simple and mild ionic gelation method upon the addition of a sodium tripolyphosphate solution to a low-molecular-weight O-HTCC solution. Highly cationic chitosan nanoparticles were prepared. Bovine serum albumin (BSA), a model protein drug, was incorporated into the nanoparticles. The physicochemical properties of the nanoparticles were determined with transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared analysis, differential scanning calorimetry, and X-ray diffraction (XRD) patterns. The results showed that increasing the BSA concentration from 1.5 to 2.5 mg/mL promoted the BSA encapsulation efficiency from 57.3% to 87.5% and the loading capacity from 70.2% to 99.5%. Compared with the chitosan nanoparticles, the O-HTCC nanoparticles had lower burst release. TEM revealed that the BSA-loaded O-HTCC nanoparticles were smaller than the O-HTCC nanoparticles when the BSA concentration was 1.5 mg/mL; SEM showed that the size of the BSA-loaded O-HTCC nanoparticles was mostly affected by the BSA concentration, and the increase in size occurred with the concentration increasing. Thermograms and XRD of the BSA-loaded nanoparticles suggested that polyelectrolyte–protein interactions increased with the BSA concentration increasing and greater chain realignment in the BSA-loaded nanoparticles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009