Superparamagnetic Fe3O4 nanoparticles are appealing materials for heat activated killing of
cancer cells. Here, we report a novel method to enhance the heat activated killing of
cancer cells under an AC magnetic field (AMF) by introducing a
polyaniline impregnated shell onto the surface of Fe3O4 nanoparticles. These
polyaniline shell cross-linked magnetic nanoparticles (PSMN) were prepared by in situ polymerization of
aniline hydrochloride on the surface of carboxyl PEGylated Fe3O4 nanoparticles. XRD and TEM analyses revealed the formation of single phase inverse
spinel Fe3O4 nanoparticles of a size of about 10 nm. The successful growth of the
polyaniline shell on the surface of carboxyl PEGylated magnetic nanoparticles (
CPMN) is evident from FTIR spectra, DLS, TGA, zeta-potential and magnetic measurements. Both
CPMN and PSMN show good colloidal stability, superparamagnetic behavior at room temperature and excellent heating efficacy under AMF. It has been observed that the heating efficacy of PSMN under AMF was slightly reduced as compared to that of
CPMN. The enhanced toxicity of PSMN to
cancer cells under AMF suggests their strong potential for magnetic
hyperthermia. Furthermore, PSMN shows high loading affinity for an anticancer
drug (
doxorubicin), its sustained release and substantial internalization in
tumor cells.