Study of chitosan coatings on nanoparticles for biomedical applications

Of late, much work and interest had been generated in the fields involving nanoparticles. Due to their nanometer scale, these particles have been proven to be promising in diverse applications such as electronics and medicine, amongst others. In addition, an emerging and attractive use of nanoparticles as biotherapeutic delivery agents within the body was introduced. However, in order to use these nanoparticles in any biomedical application, they must be rendered biocompatible. In this paper, we attempt to coat chitosan, a naturally-occurring polymer which is biocompatible, biodegradable and nontoxic, onto the surfaces of nanoparticles. 5 nm gold (Au) nanoparticles were chosen for our study as they are commercially available. The presence of a chitosan shell not only renders these nanoparticles biocompatible, the amino and hydroxyl groups of chitosan also allow the immobilization of many biotherapeutic agents. The relationship between the concentration of the chitosan used in the coating process and the thickness of the chitosan shell formed is investigated. It is hoped that the results of this study can also be applied to other nanoparticles, in addition to Au, that are intended to be used in bioapplications.