The Role of Crocetin-Loaded PLGA Nanoparticles as a Pre-Treatment Agent on Indocyanine-Photodynamic Therapy of Breast Cancer Cell

Photodynamic therapy (PDT) can be considered as a non-invasive method for cancer treatment. One of the most commonly of a water-soluble dye photosensitizer (PS) used in photothermal therapy (PTT) and PDT is Indocyanine Green (ICG). However, high ‎cytotoxicity in high concentration and instability in aqueous media were limited its application. ‎It was shown that using nanoparticles or plant extracts in combination with PS could improve PDT efficiency. In this study, anti-cancer properties of crocetin (Crt) loaded PLGA (Poly lactic-co-glycolic acid) nanoparticles (NPs) were utilized to increase the PDT efficacy with ICG on the MCF-7 cells.
Crt was encapsulated into PLGA NPs and its particle size distribution and encapsulation efficiency were evaluated. IC10 of Crt, PLGA-Crt NPs and ICG was determined by MTT assay in MCF-7 cancer cells. At these concentrations, the cells were pre-treated with Crt or PLG-Crt, then treated with ICG and finally exposure to near infrared (NIR) laser with 2.5 W powers at different times. The cells viability was evaluated by the MTT assay.
The findings showed no dark cytotoxicity due to ICG (12.9 μM), Crt or PLGA-Crt alone. But NIR laser irradiation in the presence of ICG after cells pre-treatment by the Crt or PLGA-Crt NPs leads to induce cell death to (61.6 ±7) % and (75.5 ±5) %, respectively (P<0.05).
The results demonstrated that PLGA-Crt NPs in combination with ICG could improve PDT outcomes more efficiently in comparison with Crt and ICG. Therefore, this method could be effective in breast cancer therapy with low cytotoxicity.