Combined thermo-chemotherapy of cancer using 1 MHz ultrasound waves and a cisplatin-loaded sonosensitizing nanoplatform: an in vivo study.

Purpose: The aim of the present study was to develop a new strategy for combined thermo-chemotherapy of cancer. For this purpose, we used ultrasound waves [1 MHz; 1 W/cm; 10 min] in combination with a sonosensitizing nanoplatform, named ACA, made of alginate co-loaded with cisplatin and gold nanoparticles (AuNPs).

Methods: Various combinatorial treatment regimens consisting of ultrasound, AuNPs, cisplatin, and ACA nanoplatform were studied in vivo. The CT26 colon adenocarcinoma cell line was used for tumor induction in BALB/c mice. During the ultrasound exposure, we monitored the temperature variations in each treatment group using infrared thermal imaging. Furthermore, tumor metabolism was assessed by [18F]FDG (2-deoxy-2-[18F]fluoro-D-glucose)-positron emission tomography (PET) imaging.

Results: The combination of ultrasound with nanoplatform showed an improved therapeutic efficacy than free cisplatin or ultrasound alone. It was revealed that the examined thermo-chemotherapy protocol has the potential to intensively decrease the metabolic activity of CT26 tumors.

Conclusions: The data obtained in this study confirmed a potent anti-tumor efficacy caused by the ACA nanoplatform and ultrasound combination. It may provide a beneficial cancer therapy strategy in which the thermal and mechanical effects of ultrasound can intensify the therapeutic ratio of conventional chemotherapy methods.