Cytotoxic effect of zinc oxide nanoparticle and diode laser combination in colorectal cancer in vitro via induction of cell cycle arrest and apoptosis

The fourth deadliest reason for cancer-related deaths worldwide was found to be colorectal cancer. Zinc oxide nanoparticles (ZnO NPs) have been researched for biomedical applications due to their demonstrated anticancer, antidiabetic, antibacterial, and anti-inflammatory activities. The cytotoxic reactive oxygen species (ROS) that are produced when photosensitizers (PSs) are activated by light, which in turn cause cancer cell death, and photodynamic treatment (PDT) causes selective cytotoxicity to malignant cells. The cytotoxic effect of different concentrations of nanoparticles and laser wavelengths was studied on colorectal cancer cell line (CaCo2), while the use of combination therapy had clear effects on early apoptosis. The half-maximal inhibitory concentration (IC50) of nanoparticles for the cells was evaluated. The proper IC50 for CaCo2 cells was 20 ug/ml Zinc oxide nanoparticle and Diode laser power is 5 j/cm2. The percentage of cells that decreased in the G2 phase of the cell cycle relative to the S and G1 phases was significantly different when the combination of laser and zinc nanoparticles was used. Combined use of a diode laser and ZnO2 significantly inhibited the spread of cancer by boosting the expression of the p53 gene. Bax, a central cell death regulator, was expressed significantly in combined treatments. However, combined use of the laser and ZnO2 did not reveal any substantial differences in the Bcl2 gene. In conclusion, this study suggests that combination therapy was cytotoxic to CaCo2 cells in vitro and there is a possibility of developing it as an effective therapeutic agent.