Preparation of ICG-FePt nanoparticles promising for magnetic resonance imaging contrast agent and hyperthermia applications

The use of superparamagnetic FePt nanoparticle for biomedical applications has been investigated. Indocyanine green (ICG) is a tricarbocyanine approved by the U.S. FDA for use in humans for fluorescence imaging and diagnosis in clinical applications. Using a simplified method, we successfully synthesized FePt nanoparticles and modified the surfaces of the nanoparticles with various functional agents. By heating the FePt nanoparticles, 2-aminoethanethiol and indocyanine green were transferred onto the FePt nanoparticles without the use of toxic chemicals, and multiple functional nanomaterials were produced. The promising nanotheranostic materials were constructed for fluorescence and magnetic guidance dual-modals by the introduction of chemical bonds between ICG and 2-aminoethanethiol, which was transferred onto magnetic FePt nanoparticles. It was proven that the resulting composites with an average diameter of 1.85 nm could be stimulated to high temperature elevation rates with high-frequency induction heating. Different concentrations of FePt nanoparticles had excellent heating rates that were at least 0.016 cal/s, which demonstrated that the materials could serve as an outstanding agent for hyperthermia therapy in cancer. 3T Magnetic Resonance (3T-MR) imaging showed that the nanoparticles had excellent concentration-dependent contrasting effects, demonstrating promise for use as a contrast agent with good biocompatibility.