A MnFe2O4/C nanocomposite as a novel theranostic agent in MRI, sonodynamic therapy and photothermal therapy of a melanoma cancer model

Abstract

Photothermal therapy (PTT) and sonodynamic therapy (SDT) using nanomaterials are in progress as alternative modality of cancer therapy. Herein, a nanocomposite comprising MnFe2O4 and carbon (MnFe2O4/C) was synthesized and characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometery and X-ray diffraction. MnFe2O4/C had a saturation magnetization of 13.250 emu g−1, a coercivity of 13.204 G and a magnetic moment of 0.55, and comprised uniform spherical particles with a mean diameter of 221.6 ± 22 nm and cracked surface. The spheres had a carbon entity accompanied by embedded cubic spinel-type MnFe2O4 dots of 2.1 ± 0.6 nm in diameter. MnFe2O4/C was then introduced as a new absorbing agent of both 808-nm laser light and ultrasound (US) wave in treatment of C540 (B16/F10) cancer cells and melanoma tumor bearing mice. Simultaneously, MnFe2O4/C can act as a contrast agent for magnetic resonance imaging. While MnFe2O4/C was relatively biocompatible both in vivo and in vitro, and 808-nm laser light and US waves of 1.0-MHz had negligible effects on the tumor cells, the laser light and US waves at power densities of 0.5 and 1.0 W cm−2 activated MnFe2O4/C to kill the C540 (B16/F10) cancer cells and destroyed the tumor. Cell viability upon irradiation of both the laser light and US in the presence of 25 μg mL−1 MnFe2O4/C reached 21.5 and 4.6% at the power densities of 0.5 and 1.0 W cm−2, respectively. On the other hand, histological analyses indicated that intratumoral injection of MnFe2O4/C along with laser light and US irradiations led to a deep tumor tissue necrosis. A highly contrast induction in the magnetic resonance images of MnFe2O4/C along with its PTT and SDT efficacies introduced it as a novel theranostic agent in nanomedicine.