Synthesis of citric acid-coated nanomaterials releasing oxygen and antioxidant vitamin E and investigation of their effects on healthy and cancer cells under hypoxic and normoxic conditions

experiments are consistent with each other in terms of cell viability, ROS, and NO production. In general, CPE increases the viability of healthy cells by 25% while decreasing ROS, NO and lipid peroxidation, and increases ROS, NO and lipid peroxidation in cancer cells while decreasing cell viability by 11% in hypoxic environments. The observed results are interpreted as follows: cancer cells typically exhibit high basal ROS levels and limited antioxidant buffering capacity. Therefore, an increase in oxygen availability, combined with citric acid and vitamin E, can cause acute oxidative imbalance. Under these conditions, moderate ROS accumulation can increase oxidative stress and lipid peroxidation, ultimately inhibiting cancer cell proliferation. In contrast, healthy cells possess more efficient antioxidant defense systems. The presence of oxygen, citric acid, and vitamin E together can support normal oxygen-dependent metabolism while protecting cell membranes from lipid peroxidation, thanks to citric acid's metal chelation properties and vitamin E's antioxidant activity.