PEGlatyon-SPION surface functionalization with folic acid for magnetic hyperthermia applications

Abstract

Superparamagnetic iron oxide nanoparticles (SPION) are of great interest for application in magnetic fluid hyperthermia (MFH) due to their heat generation capability in an external alternating magnetic field, besides biocompatibility, and surface properties. MFH has emerged as a promisor therapeutic approach for cancer treatment and is based in controlled heating tumor tissue through the accumulation of SPIONs within cancer cells. This work describes a new route for the preparation of folate-conjugated PEGylated SPIONs, which involves the attachment of such molecules at the surface through polycondensation reactions, without the need for coupling agents or prior modification on the species involved. The size of iron oxide cores obtained by transmission electron microscopy was about 12 nm. The conjugation of folate onto SPIONs was confirmed by FTIR spectroscopy. The folate conjugated nanoparticles were colloidal stable in PBS, presenting a hydrodynamic diameter of 109 ± 1 nm and PDI 0.148. The obtained folate-targeted PEGylated SPIONs showed superparamagnetic behavior with a saturation magnetization of 73.1 emu·g−1 at 300 K. Their specific absorption rate (SAR) ranged from 32.8 to 15.0 W g−1 in an alternating magnetic field of 10–16 kA m−1 and frequency of 420–203 kHz. The heat generated was sufficient to raise the sample temperature to the therapeutic range used in MFH establishing this system as promising candidates for use in MFH treatment.