Hyperthermic Agent Prepared by One-Pot Modification of Maghemite Using an Aliphatic Polyester Model

This paper presents the preparation of a hyperthermic agent by the direct modification of magnetic nanoparticles via grafting of an aliphatic polyester model, the low molecular weight poly(lactic acid), PLA. This grafting was carried out in dispersion, where particles modified with lactic acid were grafted to the PLA using an aromatic diisocyanate. The prepared materials were studied by several techniques, such as Fourier transform infrared spectroscopy (FTIR), small-angle X-ray scattering (SAXS), thermogravimetric analysis (TGA) and magnetic force. The results showed that the synthesis and modification of nanoparticles were performed successfully and that the obtained products presented magnetic force values able to make them useful in biomedical applications, such as magnetic hyperthermia. In this sense, the prepared materials heated using 200 A and 300 A presented Specific Absorption Rate equal to 1254 and 3762 W/kg, respectively. In other words, 20 mg/mL dispersions of these nanomaterials, heated using 200 and 300 A, can increase the temperature up to 39 and 69°C, respectively. Thus, tested media achieved temperatures which can induce tumor cell death, constituting an attractive alternative in the fight against cancer. Therefore, besides the low cost and ease of production, the materials produced here present encouraging results, which may allow their future use in cancer therapy.