Ameliorative effect of zinc oxide-chitosan conjugates on the anticancer activity of cisplatin: Approach for breast cancer treatment

Breast cancer is the second most prevalent cancer affecting both males and females, comprising nearly 30 % of all cancer cases. While chemotherapeutic agents, such as cisplatin (Cis), have proven successful in cancer treatment, concerns persist regarding their efficacy and the potentially dangerous side effects. Consequently, there is a crucial and ongoing need to develop approaches that minimize side effects associated with chemotherapy. In the present work, various types of nanoparticles (NPs) were synthesized and loaded with Cis. Cis was conjugated with nanocarriers such as zinc oxide (ZnO), ZnO modified with mandelic acid and graphene oxide (GO), chitosan (CS), and CS modified with ZnO and GO to enhance the selectivity of Cis towards cancer cells. Zeta potentials and particles size were assessed using electrophoretic light scattering and dynamic light scattering. NPs were char-acterized using transmission electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. The impact of standalone Cis as well as its nanoconjugated form on the behavior of MCF-7 cell line was investigated using WST-1 cell proliferation and apoptosis/necrosis assays. Experimental findings revealed that among the various NPs tested, ZnO, and CS NPs exhibited the highest loading percentage of Cis, surpassing the loading percentages achieved with other NPs. Cytotoxicity assay showed the enhanced effect of Cis when con-jugated with ZnO and CS NPs. Flow cytometry-based assays and confocal microscopy confirmed that ZnO/Cis and CS/Cis induced apoptosis. The cisplatin-nanocomplex exhibited a descending order of early apoptosis and late apoptosis in the following order: ZnO, Cis, CS, ZnO-M, CS-GO, ZnO-GO, CS-ZnO, and CS-ZnO, Cis, CS, CS-GO, ZnO-M, ZnO, ZnO-GO, respectively. None of the nanoparticle complexes displayed a significant percentage of necrotic cells, with the highest percentage reaching 4.65 % in the case of CS-GO/Cis.