Breast cancer, the second most common type, and ovarian cancer, the most lethal among tumors of the female reproductive system, stand out due to their high incidence and mortality rates. The development of new therapeutic strategies supported by nanotechnology has gained prominence owing to the controlled and targeted delivery of drugs. In parallel, the role of the immune system in cancer treatment has driven the advancement of numerous studies in the field of immunotherapy, particularly those focused on eliciting an effective immune response against tumors, such as approaches based on dendritic cell activation and maturation. Previous studies have demonstrated the in vitro efficacy of maghemite nanoparticles associated with methylene blue (MAGCIT-AM) for the treatment of breast and ovarian cancers.

Based on these findings, the present study investigated the application of MAGCIT-AM with the aim of promoting an antitumor immune response in vitro for the treatment of breast and ovarian cancers.

For this work was used two human breast carcinoma cell lines (MDA-MB-231) and one ovarian cancer cell line (A2710), MAGCIT-MB was synthesized through hydrothermal coprecipitation in an alkaline medium at 100°C, surface functionalization was performed using a citric acid solution, by applying the solution aggregation method (0.05 M) to maghemite nanoparticles at a concentration of 90 mg/L. The analysis was performed using flow cytometry (FACSCanto II and FACSCalibur).

Two human breast carcinoma cell lines (MDA-MB-231 and T-47D) and one ovarian cancer cell line (A2780) were used. MAGCIT-AM exhibited a hydrodynamic diameter of 60.93 nm, a polydispersity index of 0.199, and a zeta potential of −20.9 mV. Analysis of flow cytometry revealed modulation of lipid droplet biogenesis by BODIPY, reduction in mitochondrial membrane potential by JC-1 dye, and dendritic cell maturation, evidenced by increased expression of specific markers, like CD11c, CD86, HLA-DR, CD25 and CD40.

Suggesting that cell death induced by MAGCIT-AM is capable of promoting dendritic cell maturation, thereby reinforcing its potential as a therapeutic strategy for breast and ovarian cancer.