Enhanced photothermal heating and combination therapy of gold nanoparticles on a breast cell model

Multi-drug resistance (MDR) in addition to the damage to non-malignant normal cells are the most difficult in cancer treatment. Drug delivery and Plasmonic photothermal therapy based on the use of resonant metallic nanoparticles have developed as promising techniques to destroy cancer cells selectively. In the present work, gold nanoparticles (AuNPs) were synthesized using trisodium citrate. The prepared AuNPs have a small size of 14 ± 4 nm and exhibit high stability with Zeta potential - 18 mV, AuNPs showed higher photothermal heating efficiency compared to irradiation with a 532 nm laser alone on the breast cancer cell line (MCF-7). Treatment of MCF-7 cells with 0.125 mM AuNPs coupled with laser irradiation for 6 min was found to significantly reduce (34%) the cell viability compared to 5% obtained with AuNPs in the same concentration and 26% with laser irradiation for 6 min without AuNPs. Moreover, the prepared AuNPs were used as an anticancer drug carrier for Doxorubicin (Dox), upon loading Dox to AuNPs there was a slight increase in the particle size to 16 ± 2 nm, FT-IR spectroscopic results showing the binding of Dox to AuNPs was through the -NH group. The potential cytotoxicity of the DOX@AuNPs nanocomposite was significantly increased compared to free DOX on the MCF7 cell line with a decrease in IC₅₀. All these results suggested the potential use of AuNPs as therapeutic photothermal agents and drug carriers in cancer therapy.