Introduction

Magnetic Hyperthermia (MH) uses magnetic nanoparticles (MNPs) when exposed to alternating magnetic field to produce heat; a method used for the focal treatment of tumours. The efficacy of the MH treatment is linked to the heating efficiency of the MNPs, measured in specific absorption rate (SAR) values: higher are the SAR values more performing are the MNPs. Several studies have demonstrated that the heating efficiency can be improved by tuning the crystallinity, shape, size and size distribution of MNPs; all these parameters can be adjusted in order to increase the effectiveness of the treatment and decrease the patient administer MNPs doses.

Technical features

A new method has been developed for preparing MNPs having controlled structural and magnetic properties to be used as thermal mediators in magnetic hyperthermia, in biomedical applications. In previous patent the inventors disclosed a method for preparing ferrite nanoparticles of cubic- like shape, WO2020222133A1. Here, the inventors have now found that, by using alternative aldehyde and/or ketone directing agents, it is possible to obtain ferrite nanoparticles with other controlled geometrical shapes.  For example, faceted or spherical shapes can be obtained, which show high SAR values, making them suitable for use in MH applications. The synthesis method of the present invention provides, in a scaled-up manner, ferrite nanoparticles having controlled size (in the range of about 9-45 nm), shapes and crystallinity and showing outstanding heating performances of up to 475W/gFe for faceted nanoparticles and at frequency and amplitude field of clinical use (100 kHz and 24 kA/).

Possible Applications

• Magnetic Hyperthermia;
• Targeted tumour treatment;
• Drug delivery.

Advantages

• Allows to optimal control of MNPs size, size dispersion, form and colloidal properties;
• Outstanding heating performance of the MNPs;
• Does not require operating in an atmosphere devoid of oxygen and under magnetic agitation;
• Low cost and scalable method (grams scale).