Induction of Immunogenic Cell Death of Cancer Cells through Nanoparticle-Mediated Dual Chemotherapy and Photothermal Therapy

Abstract The use of nanomedicines to induce immunogenic cell death is a new strategy that aims to increase tumor immunogenicity and thereby prime tumors for further immunotherapies. In this study, we developed a nanoparticle formulation for combinatory chemotherapy and photothermal therapy based only on materials previously used in FDA-approved products and investigated the effect of the combinatory therapy on the growth inhibition and induction of immunogenic cell death in human MDA-MB-231 breast cancer cells. The formulation consists of ~108-nm nanoparticles made of poly(lactic acid)-b-methoxy poly(ethylene glycol) which carry doxorubicin for chemotherapy and indocyanine green for photothermal therapy. A 0.3 mg/mL suspension of NPs increased the medium temperature up to 10 °C upon irradiation with an 808-nm diode laser. In vitro studies showed that combination of laser assisted indocyanine green-mediated photothermal therapy and doxorubicin-mediated chemotherapy effectively eradicated cancer cells and resulted in the highest level of damage-associated molecular pattern presentation (calreticulin, high mobility group box 1, and adenosine triphosphate) compared to the individual treatments alone. These results demonstrate that our nanoparticle-mediated combinatory approach led to the most intense immunogenic cell death when compared to individual chemotherapy or photothermal therapy, making it a potent option for future in vivo studies in combination with cancer immunotherapies.