Harnessing the Chemo-photothermal Effects of Magneto-polymeric Nanohybrids for Near-Infrared (NIR) Responsive Delivery of Doxorubicin in Cancer Cells

Abstract

Photothermal therapy is currently the most discussed noninvasive therapy for eradicating cancer cells due to its ability to penetrate deeper tissues. A number of NIR-responsive nanomaterials have been effectively used along with anticancer drugs that can potentially exhibit combined chemo-photothermal effects, which can provide multistrategy approaches toward cancer management. This research mainly focused on the ultrasonic atomization-led synthesis of NIR-responsive nanohybrids with chitosan and gold-coated iron oxide nanoparticles loaded with doxorubicin (DOX) (CGMD nanohybrids), and the study of their chemo-photothermal application toward the eradication of cancer. The functional and morphological characterization of the CGMD nanohybrids was performed using various techniques, including absorption spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Dynamic Light Scattering (DLS), and ζ-potential measurements. The synthesized nanohybrids were monodisperse, with a mean particle size of 118 ± 13 nm, incorporating gold-coated iron oxide nanoparticles of 27 ± 9 nm. The encapsulation of DOX in the nanohybrids was found to be 82.37 ± 7%, and released approximately 51% of DOX over a period of ∼7 days, demonstrating a sustained and controlled release profile. The photothermal efficacy was determined with NIR laser exposure (808 nm, 0.6W) for 10 min, which resulted in a 24.9 °C rise in the temperature. The CGMD nanohybrids exhibited 7× faster DOX release with multiple NIR stimulations. Several in vitro studies have been performed with CGMD nanohybrids on MCF-7 breast cancer cells. Without laser exposure, the CGMD nanohybrids exhibited cytotoxic effects on MCF-7 breast cancer cells with an IC50 of 1.05 μg/mL after 48 h of incubation. In contrast, upon laser exposure, an improved cytotoxic effect was observed in just 12 h. The results were then translated to a 3D spheroid model generated from MCF-7 cells. Overall, the CGMD nanohybrids demonstrated enhanced efficacy in inhibiting cancer cell proliferation in both 2D and 3D cell models using dual chemo-photothermal therapy.