Plasmonic hyperthermia or radiofrequency electric field hyperthermia of cancerous cells through green-synthesized curcumin-coated gold nanoparticles.

Nanoparticle-mediated hyperthermia is one of the prominent adjuvant therapies which has been faced by many problematic challenges such as efficiency and safety. To compare the nanoparticle-mediated photothermal therapy and radiofrequency electric field hyperthermia, green-synthesized curcumin-coated gold nanoparticles (Cur@AuNPs) were applied in an in vitro study. Using recently published methodologies, each step of the study was performed. Through green chemistry, curcumin was applied as both a reducing and a capping agent in the gold nanoparticle synthesis process. Various techniques were applied for the characterization of the synthesized nanoparticles. The heating rate of Cur@AuNPs in the presence of RFEF or laser irradiation was recorded by using a non-contact thermometer. The cellular uptake of the Cur@AuNPs was studied by ICP-AES. The cellular viability and apoptosis rate of different treatment were measured to investigate the effect of two different nano-hyperthermia techniques on the murine colorectal cancer cell line. The average size of Cur@AuNPs was 7.2 ± 3.3 nm. The stability of the gold nanoparticles in the phosphate buffer saline with and without fetal bovine serum was verified by UV-Vis spectroscopy. FTIR, UV-Vis spectroscopy, and TEM indicate that the stability is a result of phenolic coating on the surface of nanoparticles. Cur@AuNPs can absorb both light and radiofrequency electric field exposure in a way that could kill cancerous cells in a significant number (30% in 64 μg/ml concentration). Green-synthesized Cur@AuNPs could induce apoptosis cell death in photothermal therapy and radiofrequency electric field hyperthermia.