Multiwalled Carbon Nanotubes Decorated with Mn_0.5Zn_0.5Fe₂O₄ Nanoparticles for Magneto-Photothermal Cancer Therapy

Alternative cancer treatments such as photothermal therapy (PTT) and magnetic hyperthermia (MHT) techniques have been studied to show promising potential as supplementary modalities. However, such techniques have their own limitations; for instance, highly concentrated intratumoral injections of magnetic nanoparticles are required to compensate their low specific loss power under safe and low magnetic field intensity for the MHT, while the PTT has limitations in the treatment of deep-seated tumors due to low light penetration. Here, the decoration of the multi-walled carbon nanotube (MWCNT) surface by magnetic nanoparticles (≈8.5 nm) was achieved by a hydrothermal method and the development of MWCNT/Mn 0.5 Zn 0.5 Fe 2 O 4 (MZFC) hybrids for magneto-photothermal dual-mode cancer therapy. The obtained specific loss power of the MZFC hybrids is found to be at least 1 order of magnitude higher, with improvement from ∼19 W/g to 225 W/g, under the excitation of both an AMF with a magnetic field intensity of 6.4 kA/m and a frequency of 300 kHz and a simultaneous NIR laser of 0.5 W/cm 2 irradiation. The synergistic utilization of the photothermal and magnetic properties of MZFC effectively diminishes the required magnetic field amplitude and NIR laser power density. Our in vitro cell experiments confirmed that the thermal effects mediated by the MZFC after endocytosis delivered enhanced cytotoxicity in the presence of dual excitation of NIR laser and AMF. These findings indicate that MZFC nanohybrids possess significant potential as targeted nanoheating agents for hyperthermia applications.