Preparation and evaluation of chitosan-based nanoparticles containing immunestimulating agents

Abstract

In this work, chitosan-based nanoparticles were applied to enhance efficacy of the immunostimulating agents. Lactoferrin (LF) and fucoidan (FUC) were chosen as immunostimulating agents. As to LF, chitosan/alginate/calcium complex microparticles were prepared as its drug carrier. The microparticles had a size of 1 – 2 μm, and showed relatively high LF content. The LF content and release rate were depended on the concentration of the chitosan solution used for the treatment of microparticles. Efficacy was investigated by the pre-treatment with oral administration to rats with carrageenan-induced edema. The microparticles exhibited better efficacy than LF solution. In addition, chitosan-based nanoparticles containing FUC were prepared and evaluated on the usefulness. From the particle characteristics, N-trimethylchitosan(TMC)/FUC nanoparticles were considered to be possibly useful nanoparticles, rather than chitosan/FUC nanoparticles. TMC/FUC nanoparticles had a size of 320 nm and contained FUC at 47% (w/w). Efficacy was examined by the pre-treatment or post-treatment with oral administration using mice with sarcoma-180 solid tumor. In both treatments, TMC/FUC nanoparticles exhibited better suppression of tumor growth than FUC solution. The nanoparticles were considered to enhance the antitumor efficacy due to the promotion of immune induction etc. These results suggested the chitosan-based micro- or nanoparticles should be available for the enhancement of the functions of immunomostimulating agents.