In-vitro evaluation of layered double hydroxide–Fe3O4 magnetic nanohybrids for thermo-chemotherapy

Among two-dimensional nanomaterials, layered double hydroxides (LDHs) are of great interest in biomedical applications due to their unique properties and layered structure. Superparamagnetic iron oxide nanoparticles (Fe3O4) are also well known for their tailorable properties, high magnetization values and biocompatibility. The objectives of our current work are to combine LDHs with magnetic nanoparticles in order to widen the horizons of their applications in cancer therapy. This work undertakes a facile chemical approach for the fabrication of Fe3O4-conjugated Mg–Al layered double hydroxide magnetic nanohybrids (MNHs). The successful fabrication of these MNHs was evident from X-ray diffraction analysis, infrared spectroscopy, X-ray photoelectron spectroscopy, and zeta potential measurements. These MNHs were explored as possible heating platforms for magnetic hyperthermia as well as drug-delivery vectors to cancer cells. A high degree of drug-loading efficiency (∼99%) for doxorubicin (Dox), with ∼90% release in high proton environments was observed. In addition, the nature of the host–drug interactions was systematically investigated by fluorescence spectroscopy. These MNHs were seen to be biocompatible with murine fibroblast (L929) and human cervical (HeLa) cell lines. To exemplify the therapeutic performances of Dox-loaded MNHs, the IC50 (50% inhibitory concentration) value was also evaluated against HeLa cells. Calorimetric measurements revealed the specific absorption rates of 98.4 and 73.5 W g−1 for Fe3O4 and MNHs, respectively. In addition, the MNHs acted as a “cut-off switch” to maintain the hyperthermic temperature. As hyperthermia agents, these MNHs showed that a 20 min exposure to an alternating current magnetic field (ACMF) is adequate to inhibit the proliferation of HeLa cells and decrease the cell population significantly. In conclusion, the results established that these MNHs open up avenues of much more effective anticancer therapy.