Effective Cancer Theranostics with Polymer Encapsulated Superparamagnetic Nanoparticles: Combined Effects of Magnetic Hyperthermia and Controlled Drug Release

A combination of chemotherapy with nonconventional nanoparticle based physical destruction therapy has been proposed clinically to reduce the prospect of evolution of drug resistance in cancer. Superparamagnetic nanoparticles have been actively used for synergetic cancer therapy including magnetic fluid hyperthermia (MFH) guided by magnetic resonance imaging (MRI). To explore this direction of potential applications in cancer therapy, we have functionalized superparamagnetic La_0.7Sr_0.3MnO₃ nanoparticles (SPMNPs) with an oleic acid-polyethylene glycol (PEG) polymeric micelle (PM) structure, and loaded it with anticancer cancer drug doxorubicin (DOX) in a high loading capacity (∼60.45%) for in vitro delivery into cancer cells. The micellar structure provided good colloidal stability and biocompatibility. Upon drug loading, the cancer cell death rate of 89% was comparable to free DOX (75%) for 24 h, and that the counterstrategy of DOX conjugated SPMNPs-induced hyperthermia resulted the cancer cell extinction up to 80% under in vitro conditions within 30 min. In addition, the preliminary effect of protein corona formation on in vitro drug release and delivery was studied. Finally, in vivo bio distribution of micellar SPMNPs is observed in mice model for 50 mg kg^-1 dose of SPMNPs. Taken together, polymeric micelle SPMNPs reported here can serve as a promising candidate for effective multimodal cancer theranostics such as in the combined chemotherapy-hyperthermia cancer therapy.