Efficacy of microwave hyperthermia and chemotherapy in the presence of gold nanoparticles: an in vitro study on osteosarcoma.

Hyperthermia, generated using microwave (MW), infrared, ultrasound and other methods, is often utilised as an adjuvant technique to sensitise cancer lesions to radiation therapy and chemotherapy. In the current research, MW hyperthermia efficacy in synergism with chemotherapy was investigated in the presence and absence of gold nanoparticles (GNPs). Saos-2 cell line derived from human osteogenic sarcoma was used in the study. Various experiments were performed on the cells in the presence of doxorubicin and GNPs with MW hyperthermia. All required control groups were also considered. The in vitro experiments were conducted for GNPs of 20 and 40 nm, each at two concentrations of 13.2 and 26.4 µg/mL. After 48 hours, MTT assay was performed in order to evaluate the effectiveness of therapeutic parameters on cell survival. In groups with GNP-incubated cells, the cell survival was more than 95%. After chemotherapy, survival was determined as 37.1% and 62.8% with and without 40 nm GNPs, respectively. Following the combined treatment of hyperthermia and chemotherapy, survival declined to 17% and 4.1% in the presence of 20 and 40 nm GNPs, respectively. GNPs of 40 nm diameter and 26.4 µg/mL concentration showed the highest synergistic effect on MW hyperthermia, combination of MW hyperthermia and chemotherapy, and chemotherapy, respectively. Dox with 40 nm GNPs had a higher cell destruction rate in comparison to chemotherapy alone. Although no cytotoxicity was observed from GNP incubation alone, their presence along with MW led to a decrease in survival rate, such that the lethal effects of MW hyperthermia with GNPs were comparable with that of doxorubicin. All combined treatments in the presence of 40 nm GNPs produced a higher efficiency in comparison to similar groups without GNPs and with 20 nm GNPs.