Conjugation of Monodisperse Chitosan-Bound Magnetic Nanocarrier with Epirubicin for Targeted Cancer Therapy

The conjugate of epirubicin with monodisperse chitosan-bound magnetic nanocarrier was developed and its in-vitro anticancer efficacy was evaluated. Chitosan was first carboxymethylated and then covalently bound on the surface of Fe₃O₄ nanoparticles via carbodiimide activation. Transmission electron microscopy micrograph and dynamic light scattering measurement showed that the chitosan-bound Fe₃O₄ nanoparticles were monodisperse with a mean core diameter of 13.5 nm and a hydrodynamic diameter of 17.1 nm and so could be further used as magnetic drug carriers. The adsorption study indicated that the conjugate of epirubicin and the chitosan-bound magnetic nanocarrier was stable at pH 3–7 and 25–40 °C, and a high epirubicin loading could be achieved. The desorption kinetics showed that about 80% epirubicin released from the chitosan-bound magnetic nanocarrier after 150 and 300 min in serum and 0.03 M phosphate buffer, respectively. In vitro cytotoxicity evaluation revealed that the epirubicin-loaded magnetic conjugate was able to exhibit comparable efficacy as free epirubicin did alone. Because of the combined functions of targeted therapy and diagnosis, the novel chitosan-bound magnetic nanocarrier developed in this work will be useful in biomedicine.