Polycaprolactone-coated superparamagnetic iron oxide nanoparticles for in vitro magnetic hyperthermia therapy of cancer

Magnetic hyperthermia therapy of cancer is a promising alternative for the current chemotherapy and radiation options, due to its targeting capability and lower systemic toxicity. However, agglomeration vulnerability of the nano-heating agents in aqueous solutions, low control over the heat generation and dissipation at the target region, and eschewed clearance by the renal and reticuloendothelial systems remain as the main challenges for clinical translation of this approach. Here we report superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by using a single precursor, stabilized with a controlled micellar conformation, and coated with a thin polycaprolactone biopolymer shell to achieve enhanced cytocompatibility and thermosensitivity under external alternating magnetic field (AMF) of varied intensities. The in vitro investigations indicated a negligible influence of the polymer-coated SPIONs on cell viability of human liver cancer cells (HepG2) at a maximum concentration of 100 mu g.mL(-1). However, the cell viability was reduced significantly to 40.1 +/- 0.9% within the secure hyperthermia temperature range achieved by the heating effect of polymer-coated SPIONs in presence of AMF, depicting the on/off cytotoxicity phenomenon of polymer-coated SPIONs under AMF exposure. Therefore, the developed nanostructure presents a step-change as potential targeted nano-heating agents for new therapeutic options.