Evaluation of Hyperthermic Potential and Acute Toxicity of PLGA-PEG/Magnetite Microspheres Loaded with Oxaliplatin Using Mice as a Test System

Oxaliplatin and modified magnetic nanoparticles (magnetite-lysine) are inserted into microspheres of previously synthesized poly(lactic acid-co-glycolic acid-b-ethylene glycol) PLGA-PEG to evaluate the in vitro hyperthermal potential and the acute toxicity in mice. The used nanoparticles are synthesized by the coprecipitation method, using Fe II and Fe III, and modification with lysine is performed during the synthesis. The drug and the magnetic nanoparticles are inserted into the polymer beads through oil in water (O/W) emulsion. The obtained composites are then characterized by Fourier-transform infrared (FTIR), Thermogravimetric analysis (TGA), X-ray Diffraction (XRD), and submitted to magnetic hyperthermia and acute toxicity tests. The hyperthermia tests are conducted according to an experimental design. The magnetite-lysine nanoparticles reached the temperature for the desired application and are able to raise the temperature by 6 °C at the higher investigated current, time, and concentration conditions. According to the proposed statistical study, only the test time exerted significant positive influence on the observed temperature increase, although synergies between time and concentration and between current and concentration are also significant. In vivo acute toxicity tests are also conducted with swiss mice and revealed that the prepared materials and procedures can be regarded as safe and of low toxicity.