Conversion of amine groups on chitosan-coated SPIONs into carbocyclic acid and investigation of its interaction with BSA in drug delivery systems

Abstract

Recent studies have indicated that protein adsorption onto NPs affects strongly their functions in biological mediums. In this research, a quantitative modification of superparamagnetic iron oxide nanoparticles (SPIONs), which coated with chitosan (Ch-SPIONs), was applied to examine interactions of bovine serum albumin (BSA). SPIONs were at first synthesized via co-precipitation method in alkali medium and under sonication. They were coated with chitosan in acetic acid solution for 12 h and then, an abundance of primary amine was measured by Orange-II and UV-Vis spectroscopy. After that, they reacted with succinic anhydride in different concentrations to obtain NPs with different amounts of carboxylic acid groups. Investigation of NPs interaction with BSA showed that increment of the numbers of carboxylic acid functional groups reduced BSA adsorption on the NPs. In other words, increasing carboxylic acid groups caused to enhance negative zeta potential and therefore, caused to increase the repulsive interaction with BSA.