Morphology-dependent multienzyme activity of nanoceria in antioxidant protection of MnCl2-treated PC-12 Cells, and the potential application for Parkinson’s disease treatment

[Display omitted] •CNPs in five morphologies, naming cubic, spherical, plate-, rode- and flower-like, were synthesized and characterized.•Multienzyme-mimic catalytic activities of prepared ceria nanoparticles based on crystalline external facets were evaluated and compared in a PC12 cell models, as a potentially new PD treatment approach.•Different multienzyme activity for variable morphologies of ceria nanoparticles were delighted through in vitro analysis. Parkinsonism, the second most common neurodegenerative disorder, is characterised by a range of motor and non-motor impairments resulting from the loss of dopaminergic neurons in the substantia nigra (SN) region of the midbrain. Among the several interrelated pathways that cause this degradation, recent studies have focused on the overproduction of reactive oxygen species (ROS). O2∙-, and H2O2 as the major ROS precursors can be scavenged by superoxide dismutase (SOD), and catalase (CAT) enzymes. Ceria nanoparticles (CNPs) with multi-enzyme mimicking properties have attracted much more attention through the treatment of neurodegenerative diseases. Several parameters can influence this property, such as Ce(III)/Ce(IV) ratio, surface defects, and morphological aspects of CNPs. In this study, five different morphologies of CNPs, namely cubic, spherical, plate-, rod- and flower-like, were rationally synthesized by hydrothermal method to modulate the (111), (110), and (100) exposed facets of ceria nanocrystals in a variety of additives and surfactants. The tailored morphologies of CNPs were characterised using FT-IR, EDX, Raman, PXRD, DR, BET, XPS, SEM, and TEM methods, and SOD-mimic and CAT-mimic assay kits were used to evaluate the multienzyme activities of CNPs. The results showed the successful synthesis of CNPs having cubic fluorite structure with space group Fm3m (225) and crystallite size of 9.59 nm, 14.43 nm, 18.65 nm, 12.34 nm, and 6.5 nm for cubic, spherical, plate-like, rod-like (>100 nm in length and 100 nm length) samples based on PXRD patterns. FT-IR and EDX have confirmed the elemental analysis of CNPs. SEM and TEM images revealed the morphology and sizes of the CNPs as cubic (5–30 nm), spherical (15–30 nm), plate-like (10–20 nm), rod-like, and flower-like. To assess the effect of CNP concentration on the metabolism of the PC-12 cell line, the MTT assay was used. Finally, the neuroprotective effect of CNPs was studied by ROS assay on PC-12