Colloidal stabilized lanthanum strontium manganese oxide (LSMO) by encapsulating mesoporous silica shell for cancer treatment via magnetic hyperthermia: an in vitro study

In magnetic hyperthermia therapy (MHT), the heat generated from magnetic nanoparticles (in the range of 41°-44°C) at the target tumor site under the exposure of alternating magnetic field[1]. Various studies have been achieved the desired therapeutic heat at the target tumor site by using higher dose of magnetic nanoparticles (MNPs)[2]. However, high dose of MNPs exhibited toxic effects on surrounding healthy cells. Therefore, a critical challenge is to achieve the desired temperature at a lower dose of MNPs to avoid toxic effects on healthy tissues. The desired temperature at a lower dose of MNPs could be achieved by improving its heating efficiency. In this study, the mesoporous silica encapsulation on LSMO were used as a strategy for the enhancement of heating efficiency of LSMO at a lower dose limit (Fig. a)[3]. We demonstrated that mesoporous silica coating on LSMO (MSLN) enhances the colloidal stability, biocompatibility (Fig. c) and heating efficiency. The heating efficiency of MSLN, represented as specific absorption rate, was 240W/g at 335 kHz frequency and 14 KA/m applied field. MHT resulted in 80% cancer cell death (A549) at 43°C within 45 min, as validated by MTT (Fig. d). The cell death pathway revealed that apoptosis is the main mode of cell death at 43°C, as validated using flow cytometry. These conclusions may offer the future standpoint for in-vivo use of MSLN in MHT, either as a single entity or in combination with chemotherapy. In Vivo studies are currently ongoing animal model to elucidate the same mechanism under physiological conditions.