  The interaction of magnetic nanoparticles (MNPs) with various magnetic fields
could directly induce cellular effects. Many scattered investigations have got
involved in these cellular effects, analyzed their relative mechanisms and
extended their biomedical uses in magnetic hyperthermia and cell regulation.
This review reports these cellular effects and their important applications in
biomedical area. More importantly, we highlight the underlying mechanisms
behind these direct cellular effects in the review from the thermal energy and
mechanical force. Recently, some physical analyses showed that the mechanisms
of heat and mechanical force in cellular effects are controversial. Although
the physical principle plays an important role in these cellular effects, some
chemical reactions such as free radical reaction also existed in the
interaction of MNPs with magnetic fields, which provides the possible
explanation for the current controversy. It's anticipated that the review here
could provide readers a deeper understanding of mechanisms of how MNPs
contribute to the direct cellular effects and thus their biomedical
applications under various magnetic fields.
