Cerium Nanomaterials on Cell Membrane Mechanical Property for Drug Delivery Studies

The use of nanotechnology in cancer treatment has been raising as one of the most important discoveries in science and technology. With nanomaterial as the new drug delivery system, scientists nowadays are able to find new ways to deal with cancer.

Cerium dioxide nanoparticles is a well-known functional rare earth material. Due to its unique properties,  it has a wide range of applications in fields spanning: catalysis, electrochemistry, and biology (1). CNPs has been reported having excellent therapeutic potential, specifically abnormalities associated with oxidative stress. However, in order to have better understanding and development of the biomedical applications based on those nanomaterial, the impacts of CNPs on living organism needs to be fully studied. 

In our research, CNPs with different sizes and shapes were selected. Specifically, nano-rods (~30-200nm), nano-cubes (~20-30nm) and nanoparticles (~3-20nm) fabricated by hydrothermal treatment were being chosen as the model nanoparticles for the studies. The normal skin cancer cells have been used as the living organism.

The mechanical property and the adhesion energy of cells’ membranes were analyzed with and without CNPs by using the Atomic Force Microscopy (AFM). From the Force-Distance spectroscopy mode and Hertz's model caculation, we were able to estimate the the elasticity of the cells membranes. Different concentrations (50μM, 125μM, and 250μM) of CNPs were added to the cells and then incubated for different time period (0, 15, 30 and 60 minutes). The results showed that with low concentration (50μM), the cell elasticity maintained around 20kPA. In those cells with 250μM of CNPs added, we noticed that there was a significant change in cell elasticity observed. The result also showed that by increasing incubation time, the cell elasticity has been increasing significantly and at 1hr incubated the changing in cell elasticity is maximum. However, there was no significant change in cell elasticity was observed over 1hr time period for 0.1μM and 50μM of CNPs. This result indicates that the elasticity of cell membranes depends on different nanostructures and nanoceria interaction/internalization to cell and can change significantly at high concentration but makes no effect to the mechanical property of cell at low concentration. 

(1) A. Karakoti, S. Singh, J. M. Dowding, S. Seal, W. T. Self,, 39, 4422-4432; (2010)