Neuroprotective Effect of CeO2@PAA-LXW7 Against H2O2-Induced Cytotoxicity in NGF-Differentiated PC12 Cells

Oxygen/Nitric Oxide Dual-Releasing Nanozyme for Augmenting TMZ-Mediated Apoptosis and Necrosis

Glioblastoma multiforme (GBM) is the most common and aggressive malignant brain tumor, with a poor prognosis. Temozolomide (TMZ) represents the standard chemotherapy for GBM but has limited efficacy due to poor targeting and a hypoxic tumor microenvironment (TME). To address these challenges, we developed a dual-gas-releasing, cancer-cell-membrane-camouflaged nanoparticle to deliver TMZ. This nanoceria, camouflaged with a cancer cell membrane (CCM-CeO2), targets explicitly GBM cells and accumulates in lysosomes, triggering the rapid release of TMZ. Additionally, CCM-CeO2 could release oxygen (O2) and nitric oxide (NO) in response to the TME. Synthesized using d-arginine, catalytic nanoceria could decompose excessive hydrogen peroxide (H2O2) in the TME to produce O2, while d-arginine could nonenzymatically react with H2O2 to generate NO. CCM-CeO2 could penetrate GBM spheroids to a depth of 148.3 ± 31 μm, with the O2 and NO produced, reducing HIF-1α protein expression. When loaded with TMZ, CCM-CeO2 could increase the intracellular ROS produced by TMZ, leading to lysosome membrane permeabilization and notably augmented apoptosis and necrosis in GBM cells. An in vitro antitumor assay using spheroids showed that CCM-CeO2 reduced the IC50 value of TMZ from 174.5 to 42.6 μg/mL, likely due to the catalase-like activity of nanoceria. These results suggest that alleviating hypoxia and increasing ROS produced by chemotherapeutics could be an effective therapeutic strategy for treating GBM.

Radioprotective Potency of Nanoceria

Cancer presents a significant medical challenge that requires effective management. Current cancer treatment options, such as chemotherapy, targeted therapy, radiotherapy, and immunotherapy, have limitations in terms of their efficacy and the potential harm they can cause to normal tissues. In response, researchers have been focusing on developing adjuvants that can enhance tumor responses while minimizing damage to healthy tissues. Among the promising options, nanoceria (NC), a type of nanoparticle composed of cerium oxide, has garnered attention for its potential to improve various cancer treatment regimens. Nanoceria has demonstrated its ability to exhibit toxicity towards cancer cells, inhibit invasion, and sensitize cancer cells to both radiation therapy and chemotherapy. The remarkable aspect is that nanoceria show minimal toxicity to normal tissues while protecting against various forms of reactive oxygen species generation. Its capability to enhance the sensitivity of cancer cells to chemotherapy and radiotherapy has also been observed. This paper thoroughly reviews the current literature on nanoceria's applications within different cancer treatment modalities, with a specific focus on radiotherapy. The emphasis is on nanoceria's unique role in enhancing tumor radiosensitization and safeguarding normal tissues from radiation damage.

ROS-mediated MAPK activation aggravates hyperoxia-induced acute lung injury by promoting apoptosis of type II alveolar epithelial cells via the STAT3/miR-21-5p axis

Inhibition of type II alveolar epithelial (AE-II) cell apoptosis is a critical way to cure hyperoxia-induced acute lung injury (HALI). It has been reported that miR-21-5p could reduce H2O2-induced apoptosis in AE-II cells. However, the upstream molecular mechanism remains unclear. Herein, we established a cellular model of HALI by exposing AE-II cells to H2O2 treatment. It was shown that miR-21-5p alleviated H2O2-induced apoptosis in AE-II cells. ROS inhibition decreased apoptosis of H2O2-evoked AE-II cells via increasing miR-21-5p expression. In addition, ROS induced MAPK and STAT3 phosphorylation in H2O2-treated AE-II cells. MAPK inactivation reduces H2O2-triggered AE-II cell apoptosis. MAPK activation inhibits miR-21-5p expression by promoting STAT3 phosphorylation in H2O2-challenged AE-II cells. Furthermore, STAT3 activation eliminated MAPK deactivation-mediated inhibition on the apoptosis of AE-II cells under H2O2 condition. In conclusion, ROS-mediated MAPK activation promoted H2O2-triggered AE-II cell apoptosis by inhibiting miR-21-5p expression via STAT3 phosphorylation, providing novel targets for HALI treatment.

Mesoporous Hollow Manganese Doped Ceria Nanoparticle for Effectively Prevention of Hepatic Ischemia Reperfusion Injury

Introduction

Hepatic ischemia-reperfusion injury (HIRI) is the main reason for liver dysfunction or failure after liver resection and liver transplantation. As excess accumulation of reactive oxygen species (ROS) is the leading factor, ceria nanoparticle, a cyclic reversible antioxidant, is an excellent candidate for HIRI.

Methods

Manganese doped mesoporous hollow ceria nanoparticles (MnO_x-CeO₂ NPs) were prepared, and the physicochemical characteristics, such as particle size, morphology, microstructure, etc. were elucidated. The in vivo safety and liver targeting effect were examined after i.v. injection. The anti-HIRI was determined by a mouse HIRI model.

Results

MnO_x-CeO₂ NPs with 0.40% Mn doped exhibited the strongest ROS-scavenging capability, which may due to the increased specific surface area and surface oxygen concentration. The nanoparticles accumulated in the liver after i.v. injection and exhibited good biocompatibility. In the HIRI mice model, MnO_x-CeO₂ NPs significantly reduced the serum ALT and AST level, decreased the MDA level and increased the SOD level in the liver, prevent pathological damages in the liver.

Conclusion

MnO_x-CeO₂ NPs were successfully prepared and it could significantly inhibit the HIRI after i.v. injection.

Facet-Dependent Activity of CeO2 Nanozymes Regulate the Fate of Human Neural Progenitor Cell via Redox Homeostasis

Neural progenitor cells (NPCs) therapy, a promising therapeutic strategy for neurodegenerative diseases, has a huge challenge to ensure high survival rate and neuronal differentiation rate. Cerium oxide (CeO₂) nanoparticles exhibit multienzyme mimetic activities and have shown the capability of regulating reactive oxygen species (ROS), which is a pivotal mediator for intracellular redox homeostasis in NPCs, regulating biological processes including differentiation, proliferation, and apoptosis. In the present study, the role of facet-dependent CeO₂-mediated redox homeostasis in regulating self-renewal and differentiation of NPCs is reported for the first time. The cube-, rod-, and octahedron-shaped CeO₂ nanozymes with different facets are prepared. Among the mentioned nanozymes, the cube enclosed by the (100) facet exhibits the highest CAT-like activity, causing it to provide superior protection to NPCs from oxidative stress induced by H₂O₂; meanwhile, the octahedron enclosed by the (111) facet with the lowest CAT-like activity induces the most ROS production in ReNcell CX cells, which promotes neuronal differentiation by activated AKT/GSK-3β/β-catenin pathways. A further mechanistic study indicated that the electron density of the surface Ce atoms changed continuously with different crystal facets, which led to their different CAT-like activity and modulation of redox homeostasis in NPCs. Altogether, the different surface chemistry and atomic architecture of active sites on CeO₂ exert modulation of redox homeostasis and the fate of NPCs.

Asymmetrical 3D Nanoceria Channel for Severe Neurological Defect Regeneration

Inflammation and oxidative stress are major problems in peripheral nerve injury. Nanoceria can manipulate antioxidant factor expression, stimulate angiogenesis, and assist in axonal regeneration. We fabricate collagen/nanoceria/polycaprolactone (COL/NC/PCL) conduit by asymmetrical three-dimensional manufacture and find that this scaffold successfully improves Schwann cell proliferation, adhesion, and neural expression. In a 15-mm rat sciatic nerve defect model, we further confirm that the COL/NC/PCL conduit markedly alleviates inflammation and oxidative stress, improves microvessel growth, and contributes to functional, electrophysiological, and morphological nerve restoration in the long term. Our findings provide compelling evidence for future research in antioxidant nerve conduit for severe neurological defects.

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Collagen/nanoceria/polycaprolactone conduit was prepared by asymmetrical fabrication

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The scaffold induced proliferation, adhesion, and angiogenesis in nerve repair

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The scaffold alleviated oxidative stress and inflammation in the microenvironment