Magnetic hyperthermia which exploits the heat generated by magnetic nanoparticles (MNPs) when exposed to an alternative magnetic field (AMF) is now in clinical trials for the treatment of cancers. However, this thermal therapy requires a high amount of MNPs in the tumor to be efficient. On the contrary the hot spot local effect refers to the use of specific temperature profile at the vicinity of nanoparticles for heating with minor to no long-range effect. This magneto-thermal effect can be exploited as a relevant external stimulus to temporally and spatially trigger drug release. In this review, we focus on recent advances in magnetic hyperthermia. Indirect experimental proofs of the local temperature increase are first discussed leading to a good estimation of the temperature at the surface (from 0.5 to 6 nm) of superparamagnetic NPs. Then we highlight recent studies illustrating the hot-spot effect for drugrelease. Finally, we present another recent strategy to enhance the efficacity of thermal treatment by combining photothermal therapy with magnetic hyperthermia mediated by magneto-plasmonic nanoplatforms.

Magnetic nanoparticles coated with protein-specific molecularly imprinted polymers (MIPs) are receiving an increasing attention thanks to their binding abilities, robustness and easy synthesis compared to their natural analogues also able to target protein, such as antibodies, or aptamers. Acting as tailor-made recognition systems, protein-specific molecularly imprinted polymers can be used in many in vivo nanomedicine applications, such as targeted drug delivery, biosensing and tissue engineering. Nonetheless, studies on their biocompatibility and long-term fate in biological environments are almost non-existent, although these questions have to be addressed before considering clinical applications. To alleviate this lack of knowledge, we propose here to monitor the effect of a protein-specific molecularly imprinted polymer coating on the toxicity and biodegradation of magnetic iron oxide nanoparticles, both in a minimal aqueous degradation medium and in a model of cartilage tissue formed by differentiated human mesenchymal stem cells (MSC). Iron oxide nanoparticles degradation with or without the polymer coating was monitored for a month by following their magnetic properties using vibrating sample magnetometry, and their morphology by transmission electron microscopy. We showed that the MIP-coating of magnetic iron oxide nanoparticles do not affect their biocompatibility or internalization inside cells. Remarkably, the imprinted polymer coating does not hinder the magnetic particles degradation, but seems to slow it down, although this effect is more visible when degradation occurs in the buffer medium than in cells. Hence, the results presented in this paper are really encouraging and open up the way to future applications of MIP-coated nanoparticles into the clinic.