Preparation and characterization of temperature-responsive and magnetic nanomicelles

One type of the temperature-responsive and magnetic nanomicelles was synthesized based on SPIONs (superparamagnetic iron oxide nanoparticles) and the biocompatible polymer-Pluronic F127 or its copolymer with poly(DL-lactic acid) (F127–PLA) via a facile chemical conjugation method. The magnetic nanomicelles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), a vibrating sample magnetometer (VSM), dynamic light scattering measurements (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The varying volume shrinkage of the magnetic nanomicelles was detected when increasing the temperature from 15 to 45 °C. Doxorubicin hydrochloride (DOX·HCl) was selected as a model anticancer drug to investigate the drug loading and release behavior in the buffer solutions with different pH values and in an alternating magnetic field (MF). The Alamar blue assay was performed to evaluate the biocompatibility of the micelles and the antiproliferative effect of the drug-loaded micelles. The results displayed that the magnetic micelles were safe carriers and the DOX·HCl-loaded micelles were equally effective as the free drug for suppressing the growth of tumor cells. The blood compatibility studies showed few effects on coagulation and hemolysis. Therefore, the magnetic micelles possess many great potential applications in the field of nanomedicine.