Evaluation of size, shape, and charge effect on the biological interaction and cellular uptake of cerium oxide nanostructures.

Cerium oxide (CeO2) at the nanoscale has prolifically attracted the immense interest of researchers due to its switchable oxidation states (Ce3+/Ce4+) that play a crucial role in many biological activities. The present work reports the evaluation of size, shape, and charge effect on the biological interaction with RAW 264.7 cells for three nanostructures of CeO2(CeO2NS) namely nanocubes (NCs), nanorods (NRs), and nanoparticles (NPs). These NS exhibits similar composition and have average diameter values in the order of NCs < NRs ≅ NPs. The values of zeta potential revealed the anionic nature of NS with surface charge in order of NCs < NPs < NRs. The cellular interaction of CeO2NS was analyzed for cytotoxicity, cellular uptake, and morphological studies. Quantitative determination of the uptake of CeO2NS exhibited concentration-dependent uptake in the order as NCs > NPs > NRs. The proposed possible mechanisms of cellular uptake revealed that different structures tended to use the various endocytosis pathways in different proportions.