Specific Absorption Rate Evaluation of Encapsulated SPION for Combined Hyperthermia Therapy and Drug Delivery Systems

Magnetic fluid hyperthermia is a cutting-edge medical treatment that uses an external alternating magnetic field to heat superparamagnetic iron oxide nanoparticles (SPION) to target tumor cells and raise their temperature to levels between 40 °C and 45 °C, causing the death of the cells by apoptosis. Iron oxides, particularly magnetite, are ideal for this therapy due to their strong magnetic properties, low toxicity, and the ability to control the size of the nanoparticles, which influences their heat generation capacity. Iron oxide nanoparticles coated with oleic acid were synthesized through a coprecipitation method and then dispersed in water by replacing the oleic acid with dimercaptosuccinic acid (DMSA). Finally, these nanoparticles were encapsulated with chitosan using ultrasonic techniques for their use in drug delivery systems. Several characterization techniques were employed to analyze the composition, structure, and size distribution of the nano-composite particles, including atomic force microscopy, laser diffraction, Fourier transform infrared spectroscopy, and X-ray diffraction. The heat generation capacity of the SPION was evaluated by obtaining the specific absorption rate (SAR) through the initial slope (ILM) and Box-Lucas (BLM) techniques. By adjusting the frequency and power of the magnetic field, the study successfully achieved high values of SAR, up to 400 W/g.