Enhanced Antioxidant Ability of PEG-Coated Ce_0.5Zr_0.5O₂-Based Nanofluids for Scavenging Hydroxyl Radicals

Abstract

The antioxidant therapy to preserve residual hearing is relatively recent, and the search for effective antioxidants is still ongoing. Though nanoceria has shown promising radical-scavenging capability, improving its antioxidant ability and the dispersion stability of its nanofluid, which is critical to the desired site, i.e., cochlea, still remains a major challenge. The objective of the present work is to study the radical-scavenging capability of poly(ethylene glycol) (PEG)-coated CeO 2 and Ce 0.5 Zr 0.5 O 2 nanoparticles in water and the biologically relevant fluid (PBS buffer). Nanoparticles in the size range of 4.0–9.0 nm are synthesized using the coprecipitation method and characterized using suitable techniques. The scavenging and dispersion stability of the synthesized nanofluid are analyzed using a UV–vis spectrophotometer. It is found that the addition of PEG during the synthesis process promoted the generation of finer nanoparticles with a narrow size distribution and the doping of zirconium produced a large number of defects in the crystallite structure. The PEG coating over the nanoparticles improved the dispersion stability of nanofluids without affecting their surface reactivity, and it is found to be 94 and 80% in water and PBS, respectively, at 500 μM and 60 min, which is maintained till 90 min. The highest scavenging of hydroxyl radicals by PEG-coated Ce 0.5 Zr 0.5 O 2 is found to be 60%, which is significantly superior to that of CeO 2 . The scavenging capability is found to be increased with the concentration of nanoparticles, showing the best scavenging activity at 190 and 150 μM for PEG-coated CeO 2 and Ce 0.5 Zr 0.5 O 2 , respectively, and the scavenging in water is at par with that of PBS, indicating that these nanoparticles are suitable to be used in sites where a biologically relevant fluid is present, e.g., the cochlea. It is proposed that PEG-coated Ce 0.5 Zr 0.5 O 2 having an average size of ∼ 4 nm can be a potential antioxidant in relevant biomedical applications.

Ceria Nanoparticle Systems Alleviate Degenerative Changes in Mouse Postovulatory Aging Oocytes by Reducing Oxidative Stress and Improving Mitochondrial Functions

“…It is known that nanoparticles with sharp edges can cause mechanical damage to the cell membranes and are therefore considered to be less biocompatible. 30,31 Our product ultimately presented spherical shapes (Figure 2D), avoiding this biological incompatibility issue. The SEM images of CeNPs with and without LA-PEG coating both appeared spongy (Figure 2E,F).…”

“…29 On the other hand, the long-term colloidal stability and biocompatibility of nanoparticles in biofluids depend on surface adsorption or chemical binding of water-soluble macromolecules. 30 So it may be feasible to enhance CeNPs' biocompatibility and antioxidant properties by utilizing surface modification.…”

“…Lipoic acid (LA) and its reduced form, dihydrolipoic acid (DHLA), are potent intracellular antioxidants that mainly function to scavenge hydroxyl radicals, hypochlorite, and singlet oxygen, making them effective against oxidative damage in mitochondria, thus enhancing cellular mitochondrial biogenesis. , LA has hydrophilic and lipophilic characteristics, making it ideal for nanodrug delivery systems (NDDS) . On the other hand, the long-term colloidal stability and biocompatibility of nanoparticles in biofluids depend on surface adsorption or chemical binding of water-soluble macromolecules . So it may be feasible to enhance CeNPs’ biocompatibility and antioxidant properties by utilizing surface modification.…”

β-Cyclodextrin Stabilized Nanoceria for Hydrolytic Cleavage of Paraoxon in Aqueous and Cationic Micellar Media

“…Therefore, we have successfully synthesized β-cyclodextrin stabilized cerium oxide nanoparticles (β-CD@CeO 2 NPs). There are some kinds of polymers that are used to prepare water-soluble CeO 2 NPs . The electronic properties, surface functional group, composition, and morphology of β-CD@CeO 2 NPs were characterized through spectroscopic and microscopic techniques.…”

“…There are some kinds of polymers that are used to prepare water-soluble CeO 2 NPs. 32 The electronic properties, surface functional group, composition, and morphology of β-CD@CeO 2 NPs were characterized through spectroscopic and microscopic techniques. The organophosphatase activity of β-CD@CeO 2 NPs was explored by studying the kinetics of hydrolysis of paraoxon in aqueous and micellar media of the cationic surfactants (cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, trimethyl-n-tetradecylammonium bromide, cetylpyridinium chloride).…”