Enhanced efficacy of breast cancer treatment with etoposide-graphene oxide nanogels: A novel nanomedicine approach

Breast cancer represents a significant global health challenge, underscoring the need for innovative therapeutic strategies. This study explores the therapeutic potential of etoposide (ETO)-loaded graphene oxide (GO) nanogels to enhance the efficacy of breast cancer treatments. ETO-GO nanogels were synthesized and characterized using field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR). Cytotoxicity was evaluated through MTT assays on MCF-7 breast cancer cells and normal HUVEC cells. Apoptosis induction was assessed using DAPI staining, flow cytometry, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to analyze changes in gene expression. Characterization confirmed the formation of uniform, spherical nanogels with high ETO encapsulation efficiency. EDS and FT-IR analyses validated the successful loading of the drug onto the GO matrix. Cytotoxicity assays revealed a dose-dependent response, with significantly stronger effects observed in MCF-7 cells (20% viability at 100 µg/mL) than HUVEC cells (40% viability at the same concentration), indicating selective cytotoxicity. Apoptosis was verified through DAPI staining, which showed characteristics of nuclear fragmentation, and flow cytometry, identifying 15.35% of the treated cells as apoptotic. qRT-PCR analysis demonstrated an upregulation of pro-apoptotic genes (CASP3, CASP8, CASP9, BAX, PTEN) by as much as 8.3-fold, alongside a marked downregulation of the anti-apoptotic gene Bcl-2, confirming the potent induction of apoptosis by the nanogels. ETO-GO nanogels show promising potential for targeted breast cancer therapy, providing enhanced drug delivery and selective cytotoxicity. These findings warrant further in vivo studies to validate their clinical applicability.