Enhancing ovarian cancer treatment: Synergistic effects of methotrexate (Methotrexate)- and quercetin-loaded chitosan nanoparticles

• MTX/Que-loaded Cs NPs were successfully developed for treating ovarian cancer. • Higher cytotoxicity observed with MTX/Que-loaded Cs NPs compared to plain drugs. • Enhanced inhibitory effects on ovarian spheroids achieved with MTX/Que-loaded Cs NPs. • Notable anti-angiogenic effects demonstrated by MTX/Que-loaded Cs NPs over plain drugs. • MTX/Que-loaded Cs NPs significantly reduced E2F-1 and increased BAX expression. Ovarian cancer, a leading cause of cancer-related deaths in women, is often diagnosed at advanced stages and exhibits treatment resistance. This study investigates chitosan-based nanoparticles (Cs NPs) as a drug delivery system to enhance the efficacy of methotrexate (MTX) and quercetin (Que) in ovarian cancer therapy. Cs NPs were synthesized for drug delivery, and their physicochemical properties, in vitro release profiles, and cytotoxicity against OVCAR-3 cells were evaluated. The study found high encapsulation efficiencies of 97.92 % for MTX and 76.23 % for Que, with controlled release demonstrated at pH 5.7 over 50 h. Cytotoxicity assays revealed IC50 values of 57.23 ng/mL for MTX-Cs NPs and 13.22 ng/mL for Que-Cs NPs, indicating superior effectiveness compared to plain drugs. The combination treatment showed a synergistic effect (CI of 0.266), significantly enhancing apoptosis and reducing OVCAR-3 mammosphere size by 25 %. Cell migration assays indicated a reduction to 25.02 % compared to controls. The CAM assay confirmed anti-angiogenic activity, while Western blot analysis showed reduced E2F-1 and increased BAX expression. These findings suggest that MTX/Que-loaded Cs NPs could significantly improve ovarian cancer treatment outcomes.