Preparation, evaluation, and in vitro release of folic acid conjugated O‐carboxymethyl chitosan nanoparticles loaded with methotrexate

Abstract

Abstract To improve the targeted effect and reduce the neurotoxicity of methotrexate (MTX), folic acid (FA)‐conjugated O ‐carboxymethyl chitosan (O‐CMC) nanoparticles loaded with MTX were prepared via a crosslinking reaction between the carboxyl groups of O ‐CMC and Ca 2+ ions. MTX‐loaded FA–chitosan (CS) nanoparticles as controls were also prepared. The chemical structure of FA‐conjugated O ‐CMC (FA– O ‐CMC) was confirmed by 1 H‐NMR and Fourier transform infrared spectroscopy. The results show that the obtained FA– O ‐CMC nanoparticles were spherical in shape with a narrow size distribution. The encapsulation efficiency and loading capacity of MTX in the FA– O ‐CMC nanoparticles were higher than those in the FA–CS nanoparticles, and the particle size of the FA– O ‐CMC nanoparticles were also smaller than that of the control. In vitro release studies indicated that the release of MTX from FA– O ‐CMC nanoparticles was slower in the initial period, but the cumulative release was much higher. FA was also released from the nanoparticles; this might prove to be a potential antidote for preventing the neurotoxicity caused by MTX. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012