  The effect of a high frequency alternating magnetic field on HeLa tumour
cells incubated with ferromagnetic nanoparticles of manganese oxide perovskite
La0.56(SrCa)0.22MnO3 have been studied. The particles were subjected to a size
selection process and coated with silica to improve their biocompatibility. The
control assays made with HeLa tumour cells showed that cell survival and growth
rate were not affected by the particle internalization in cells, or by the
electromagnetic field on cells without nanoparticles. However, the application
of an alternating electromagnetic field to cells incubated with this silica
coated manganese oxide induced a significant cellular damage that finally lead
to cell death by an apoptotic mechanism. Cell death is triggered even thought
the temperature increase in the cell culture during the hyperthermia treatment
is lower than 0.5 C.
