Studying the effect of PDA@CeO2 nanoparticles with antioxidant activity on the mechanical properties of cells.

Studying the influence of nanomaterials on the microstructure and mechanical properties of cells is essential to guide the biological applications of nanomaterials. In this article, the effects of the first synthesized PDA@CeO2 nanoparticles (NPs) with multiple ROS scavenging activities on cell ultra-morphology and mechanical properties were investigated by atomic force microscopy (AFM). After the cells were exposed to PDA@CeO2 NPs, there was no obvious change in cell morphology, but the Young's modulus of the cells was increased. On the contrary, after the cells were damaged by H2O2, the secreted molecules appeared on the cell surface, and the Young's modulus was decreased significantly. However, PDA@CeO2 NPs could effectively inhibit the reduction of the Young's modulus caused by oxidative stress damage. PDA@CeO2 NPs could also protect F-actin from oxidative stress damage and maintain the stability of the cytoskeleton. This work investigates the intracellular antioxidant mechanism of nanomaterials from the changes in the microstructure and biomechanics of living cells, providing a new analytical approach to explore the biological effects of nanomaterials.