Protection from radiation-induced pneumonitis using cerium oxide nanoparticles

Quantum-Dot Ceramic Composites for Oxidative Stress Mitigation under Broad-Spectrum Radiation Exposure

Nanomaterials offer a promising approach to mitigating radiation-induced oxidative stress by scavenging reactive oxygen species (ROS). However, developing a nanomaterial that provides protection across a wide range of radiation conditions is challenging due to the photoelectric effects linked to the atomic number (Z) of the materials. Quantum dots (QDs) in a composite system, owing to their small size and when used at low concentrations, minimize photoelectric effects and secondary electron generation. In this study, cerium oxide (CeO2) QDs were combined with low-Z yttrium oxide (Y2O3) to create a nanocomposite (NC) (henceforth CeO2 QDs-Y2O3) that exploits the synergistic effects of both materials, providing protection across a broader spectrum of radiation. CeO2 QDs-Y2O3 demonstrated superior ROS scavenging than individual CeO2 and Y2O3 under nonradiative conditions, particularly for hydroxyl radicals (•OH) and hydrogen peroxide (H2O2), two primary ROS generated under radiation. This improved performance, due to increased oxygen vacancies and a higher Ce3+/Ce4+ ratio, indicates that these properties could help protect cells from oxidative stress during radiation exposure. Radioprotection analysis using the linear-quadratic (LQ) model revealed that the NC provided effective protection at both 150 kVp and 10 MV radiation energies. At 150 kVp, the obtained protection enhancement ratio (PER) values at 10% cell survival for CeO2 QDs-Y2O3, Y2O3, and CeO2 were 1.07, 1.16, and 0.89, respectively, suggesting that the radioprotection afforded by Y2O3 in the NC outweighed the radiosensitization of the encrusted CeO2 QDs. Additionally, despite the higher PER of Y2O3, the NC displayed increased biocompatibility toward the human keratinocyte HaCaT cell line in the absence of radiation compared to Y2O3. At 10 MV, where photoelectric effects are minimal, the NC outperformed both individual components, yielding a PER of 1.28, or a 28% dose enhancement compared to 12% for Y2O3 alone and 19% for CeO2. This study highlights the potential of CeO2 QDs-Y2O3 as a broad-spectrum radioprotective agent, offering enhanced biocompatibility and effective protection against radiation-induced oxidative stress across broad-ranging radiation conditions.

Protective effects of bone marrow mesenchymal stem cell-derived exosomes loaded cerium dioxide nanoparticle against deoxynivalenol-induced liver damage

BACKGROUND

Deoxynivalenol (DON), a mycotoxin produced by Fusarium species, posed significant threats to food safety and human health due to its widespread prevalence and detrimental effects. Upon exposure, the liver, which played a crucial role in detoxifying DON, experienced depleted antioxidant levels and heightened inflammatory responses. Bone marrow mesenchymal stem cell (BMSC)-derived exosomes (BMSC-exos) exhibited therapeutic potential by promoting cellular repair and delivering bioactive substances, such as cerium dioxide nanoparticles (CeO₂ NPs), which are recognized for their ability to mitigate oxidative stress and inflammation.

RESULTS

We successfully loaded BMSC-exos with CeO2 NPs (BMSC-exos @ CeO2) using extrusion techniques, verified through electron microscopy and elemental mapping. The resulting BMSC-exos @ CeO2 displayed low cytotoxicity, boosted antioxidant activity, and reduced inflammation in Hepa 1-6 cells with DON condition. In vivo study, BMSC-exos @ CeO2 maintained stability for 72 h, it also can prevent antioxidant depletion and inhibit liver inflammation under the DON condition. After BMSC-exos @ CeO2 treatment, multi-omics analyses further highlighted significant changes in metabolic and protein signaling pathways, notably in linoleic and arachidonic acid metabolism. Key pathways about AMPK and JAK1/STAT3 were involved in mitigating liver damage with or without DON.

CONCLUSION

Our findings revealed BMSC-exos @ CeO2 as a promising therapeutic strategy against DON's toxicity, offering valuable insights into their potential for liver protection.

Bacterial membrane-modified cerium oxide nanoboosters enhance systemic antitumor effects of radiotherapy in metastatic triple-negative breast cancer

BACKGROUND

Radiotherapy plays an important role in the treatment of triple-negative breast cancer, yet its ability to trigger systemic responses against distant tumors remains limited.

RESULTS

To address this challenge, we developed a biomimetic nanobooster by incorporating cerium oxide (CeO2) nanoparticles with bacterial outer membrane vesicles (OMVs), termed CeO2@OMV. This innovative strategy overcomes the limitations of conventional radiotherapy by enhancing antigen release and improving immune cell infiltration, thereby amplifying its effectiveness in combating both primary and metastatic tumors. The biocompatibility, antitumor effects, bystander and immunomodulatory impacts of the nanoboosters were assessed by comprehensive in vitro assays and in vivo breast cancer models. Our results demonstrated that CeO2@OMVs can selectively inhibit cancer cells while protecting normal tissue upon irradiation. Additionally, the nanoboosters induced immunogenic cell death, enhanced macrophage polarization, and suppressed the growth of bystander tumors. In vivo studies demonstrated that CeO2@OMVs, when combined with radiotherapy, significantly improved local tumor control and triggered systemic immune responses, leading to substantial inhibition of both primary and distant tumors, effectively preventing new metastases.

CONCLUSIONS

In conclusion, our CeO2@OMV nanoboosters offer a promising therapeutic strategy against metastatic breast cancer, providing a novel tool to achieve radiation-induced abscopal effects.

Surface-Functionalized Nanoceria: Dual Action in Diabetes Management via Glucose-Responsive Insulin Delivery and Oxidative Stress Mitigation

Nanoceria (NC) is gaining scientific attention due to its widespread drug delivery efficacy and modulation of oxidative stress. Herein, we developed dextran (Dex) capped insulin (INS)-loaded phenylboronic acid (PBA)-functionalized nanoceria (NC-PBA-INS-Dex) for glucose-responsive insulin delivery and mitigating excessive ROS production to regulate both hyperglycemia and oxidative stress in diabetes mellitus (DM). The prepared nanoparticle showed favorable loading capacity and excellent encapsulation efficiency of insulin. Glucose-responsive insulin release from NC-PBA-INS-Dex was observed initially in the cell-free mode when subjected to varying glucose concentrations (5.5, 11, and 25 mM). Interestingly, under in vitro setting, promising insulin release from NC-PBA-INS-Dex was found in muscle cells (major glucose storage cells) compared to lung cells against exposure to different glucose concentration suggesting a glucose-sensitive intracellular insulin delivery. NC-PBA-INS-Dex treatment further upregulated GLUT4 translocation and glucose uptake/utilization in sodium palmitate-exposed muscle cells, and results were significantly higher compared to NC or INS alone treated cells. Studies in diabetic animals demonstrated the maintenance of normoglycemia for up to 12 h upon gavaging a single dose of NC-PBA-INS-Dex compared to INS alone treatment (subcutaneous/oral). Oral administration of NC-PBA-INS-Dex also increased insulin bioavailability (in both serum and muscle tissue) compared with either subcutaneous or oral insulin administration. NC-PBA-INS-Dex further exhibited ROS scavenging (superoxide radical) potential in cell-free, in vitro, and in vivo systems, and results were comparable to treatment with NC alone. NC-PBA-INS-Dex could effectively regulate the expression of occludin and induce the reversible opening of a tight junction in intestinal epithelial cells, allowing the particle transport through the intestinal mucosa. Treatment with NC-PBA-INS-Dex did not exhibit any toxicity to in vitro and in vivo models. The NC-based drug delivery system will mimic the physiological regulation of insulin secretion in a noninvasive manner, offering improved patient compliance, reduced risk of hyperglycemia, and enhanced overall management of DM.

Safety assessment and gastrointestinal retention of orally administered cerium oxide nanoparticles in rats

Cerium oxide nanoparticles (CeO2 NPs, NM-212) are well-known for their catalytic properties and antioxidant potential, and have many applications in various industries, drug delivery, and cosmetic formulations. CeO2 NPs exhibit strong antimicrobial activity and can be used to efficiently remove pathogens from different environments. However, knowledge of the toxicological evaluation of CeO2 NPs is too limited to support their safe use. In this study, CeO2 NPs were orally administered to Sprague Dawley rats for 13 weeks at the doses of 0, 10, 100, and 1000 mg/kg bw/day, followed by a four week recovery period. The hematology values for the absolute and relative reticulocyte counts in male rats treated with 1000 mg/kg bw/day CeO2 NPs were lower than those in control rats. The clinical chemistry values for sodium and chloride in the treated male rat groups (100 and 1000 mg/kg/day) and total protein and calcium in the treated female rat groups (100 mg/kg/day) were higher than those in the control groups. However, these changes were not consistent in both sexes, and no abnormalities were found in the corresponding pathological findings. The results showed no adverse effects on any of the parameters assessed. CeO2 NPs accumulated in the jejunum, colon, and stomach wall of rats administered 1000 mg/kg CeO2 NPs for 90 days. However, these changes were not abnormal in the corresponding histopathological and immunohistochemical examinations. Therefore, 1000 mg/kg bw/day may be considered the "no observed adverse effect level" of CeO2 NPs (NM-212) in male and female SD rats under the present experimental conditions.

A Two-Generation Reproductive Toxicity Study of Cerium Nitrate in Sprague-Dawley Rats

A two-generation reproductive toxicity study was performed to evaluate the effects of cerium nitrate on the development of the parent, offspring, and third generation of Sprague-Dawley (SD) rats. A total of 240 SD rats (30 rats/sex/group) were randomly divided into four dosage groups according to body weight: 0 mg/kg, 30 mg/kg, 90 mg/kg, and 270 mg/kg. The rats were administered different dosages of cerium nitrate by oral gavage. There were no observed changes related to cerium nitrate in body weight, food consumption, sperm survival rate, motility, mating rate, conception rate, abortion rate, uterine plus fetal weight, uterine weight, corpus luteum number, implantation rate, live fetus number (rate), stillbirth number (rate), absorbed fetus number (rate), appearance, visceral, and skeletal in rats of each generation dosage group. In addition, the pathological findings showed no significant lesions associated with cerium nitrate toxicity in all tissues and organs, including reproductive organs. In conclusion, the present study showed that long-term oral gavage of cerium nitrate at 30 mg/kg, 90 mg/kg, and 270 mg/kg had no significant effect on reproduction and the developmental ability of their offspring in rats. The no-observed-adverse-effect level (NOAEL) of cerium nitrate in SD rats was higher than 270 mg/kg.

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.

Nanotechnology enabled radioprotectants to reduce space radiation-induced reactive oxidative species

Interest in space exploration has seen substantial growth following recent launch and operation of modern space technologies. In particular, the possibility of travel beyond low earth orbit is seeing sustained support. However, future deep space travel requires addressing health concerns for crews under continuous, longer-term exposure to adverse environmental conditions. Among these challenges, radiation-induced health issues are a major concern. Their potential to induce chronic illness is further potentiated by the microgravity environment. While investigations into the physiological effects of space radiation are still under investigation, studies on model ionizing radiation conditions, in earth and micro-gravity conditions, can provide needed insight into relevant processes. Substantial formation of high, sustained reactive oxygen species (ROS) evolution during radiation exposure is a clear threat to physiological health of space travelers, producing indirect damage to various cell structures and requiring therapeutic address. Radioprotection toward the skeletal system components is essential to astronaut health, due to the high radio-absorption cross-section of bone mineral and local hematopoiesis. Nanotechnology can potentially function as radioprotectant and radiomitigating agents toward ROS and direct radiation damage. Nanoparticle compositions such as gold, silver, platinum, carbon-based materials, silica, transition metal dichalcogenides, and ceria have all shown potential as viable radioprotectants to mitigate space radiation effects with nanoceria further showing the ability to protect genetic material from oxidative damage in several studies. As research into space radiation-induced health problems develops, this review intends to provide insights into the nanomaterial design to ameliorate pathological effects from ionizing radiation exposure. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Nanotechnology Approaches to Biology > Cells at the Nanoscale Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Molecular Imaging Investigations of Polymer-Coated Cerium Oxide Nanoparticles as a Radioprotective Therapeutic Candidate

Cerium oxide nanoparticles (CONPs) have a unique surface redox chemistry that appears to selectively protect normal tissues from radiation induced damage. Our prior research exploring the biocompatibility of polymer-coated CONPs found further study of poly-acrylic acid (PAA)-coated CONPs was warranted due to improved systemic biodistribution and rapid renal clearance. This work further explores PAA-CONPs' radioprotective efficacy and mechanism of action related to tumor microenvironment pH. An ex vivo TUNEL assay was used to measure PAA-CONPs' protection of the irradiated mouse colon in comparison to the established radioprotector amifostine. [18F]FDG PET imaging of spontaneous colon tumors was utilized to determine the effects of PAA-CONPs on tumor radiation response. In vivo MRI and an ex vivo clonogenic assay were used to determine pH effects on PAA-CONPs' radioprotection in irradiated tumor-bearing mice. PAA-CONPs showed excellent radioprotective efficacy in the normal colon that was equivalent to uncoated CONPs and amifostine. [18F]FDG PET imaging showed PAA-CONPs do not affect tumor response to radiation. Normalization of tumor pH allowed some radioprotection of tumors by PAA-CONPs, which may explain their lack of tumor radioprotection in the acidic tumor microenvironment. Overall, PAA-CONPs meet the criteria for clinical application as a radioprotective therapeutic agent and are an excellent candidate for further study.

Nanoceria as Safe Contrast Agents for X-ray CT Imaging

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations.

Nanodrugs with intrinsic radioprotective exertion: Turning the double-edged sword into a single-edged knife

Ionizing radiation (IR) poses a growing threat to human health, and thus ideal radioprotectors with high efficacy and low toxicity still receive widespread attention in radiation medicine. Despite significant progress made in conventional radioprotectants, high toxicity, and low bioavailability still discourage their application. Fortunately, the rapidly evolving nanomaterial technology furnishes reliable tools to address these bottlenecks, opening up the cutting-edge nano-radioprotective medicine, among which the intrinsic nano-radioprotectants characterized by high efficacy, low toxicity, and prolonged blood retention duration, represent the most extensively studied class in this area. Herein, we made the systematic review on this topic, and discussed more specific types of radioprotective nanomaterials and more general clusters of the extensive nano-radioprotectants. In this review, we mainly focused on the development, design innovations, applications, challenges, and prospects of the intrinsic antiradiation nanomedicines, and presented a comprehensive overview, in-depth analysis as well as an updated understanding of the latest advances in this topic. We hope that this review will promote the interdisciplinarity across radiation medicine and nanotechnology and stimulate further valuable studies in this promising field.

Amifostine-Loaded Nanocarrier Traverses the Blood-Brain Barrier and Prevents Radiation-Induced Brain Injury

Radiation-induced brain injury (RIBI) is a severe, irreversible, or even life-threatening cerebral complication of radiotherapy in patients with head and neck tumors, and there is no satisfying prevention and effective treatment available for these patients. Amifostine (AMF) is a well-known free radical scavenger with demonstrated effectiveness in preventing radiation-induced toxicity. However, the limited permeability of AMF across the blood-brain barrier (BBB) when administered intravenously reduces the effectiveness of AMF in preventing RIBI. Herein, we construct a nanoparticle (NP) platform for BBB delivery of AMF. AMF is conjugated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-n-[poly(ethylene glycol)]-hydroxy succinamide [DSPE-PEG-NHS, PEG M 2000], and the product is DSPE-PEG-AMF. Then, the nanoparticles (DAPP NPs) were formed by self-assembly of poly(lactic-co-glycolic acid) (PLGA), DSPE-PEG-AMF, and polysorbate 80 (PS 80). PEG shields the nanoparticles from blood clearance by the reticuloendothelial system and lengthens the drug circulation time. PS 80 is used to encapsulate nanoparticles for medication delivery to the brain. The results of our study showed that DAPP NPs were able to effectively penetrate the blood-brain barrier (BBB) in healthy C57BL/6 mice. Furthermore, in a well-established mouse model of X-knife-induced brain injury, treatment with DAPP NPs (corresponding to 250 mg/kg AMF) was found to significantly reduce the volume of brain necrosis compared to mice treated with AMF (250 mg/kg). Importantly, the use of DAPP NPs was also shown to significantly mitigate the effects of radiation-induced neuronal damage and glial activation. This work presents a convenient brain-targeted AMF delivery system to achieve effective radioprotection for the brain, providing a promising strategy with tremendous clinical translation potential.

Inhibition of melanoma using a nanoceria-based prolonged oxygen-generating phototherapy hydrogel

Tumor hypoxic environment is an inevitable obstacle for photodynamic therapy (PDT) of melanoma. Herein, a multifunctional oxygen-generating hydrogel loaded with hyaluronic acid-chlorin e6 modified nanoceria and calcium peroxide (Gel-HCeC-CaO2) was developed for the phototherapy of melanoma. The thermo-sensitive hydrogel could act as a sustained drug delivery system to accumulate photosensitizers (chlorin e6, Ce6) around the tumor, followed by cellular uptake mediated by nanocarrier and hyaluronic acid (HA) targeting. The moderate sustained oxygen generation in the hydrogel was produced by the reaction of calcium peroxide (CaO2) with infiltrated H2O in the presence of catalase mimetic nanoceria. The developed Gel-HCeC-CaO2 could efficiently alleviate the hypoxia microenvironment of tumors as indicated by the expression of hypoxia-inducible factor -1α (HIF-1α), meeting the “once injection, repeat irradiation” strategy and enhanced PDT efficacy. The prolonged oxygen-generating phototherapy hydrogel system provided a new strategy for tumor hypoxia alleviation and PDT.

Renal Clearable Mo-Based Polyoxometalate Nanoclusters: A Promising Radioprotectant against Ionizing Irradiation

In response to diffused ionizing radiation damage throughout the body caused by nuclear leaks and inaccurate radiotherapy, radioprotectants with considerable free radical scavenging capacities, along with negligible adverse effects, are highly regarded. Herein, unlike being performed as toxic chemotherapeutic drug candidates, molybdenum-based polyoxometalate nanoclusters (Mo-POM NCs) were developed as a non-toxic potent radioprotectant with impressive free radical scavenging capacities for ionizing radiation protection. In comparison to the clinically used radioprotectant drug amifostine (AM), the as-prepared Mo-POM NCs exhibited effective shielding capacity by virtue of their antioxidant properties resulting from a valence shift of molybdenum ions, alleviating not only ionizing radiation-induced DNA damage but also disruption of the radiation-sensitive hematopoietic system. More encouragingly, without trouble with long-term retention in the body, ultra-small sized Mo-POM NCs prepared by the mimetic Folin-Ciocalteu assay can be removed from the body through the renal-urinary pathway and the hepato-enteral excretory system after completing the mission of radiation protection. This work broadened the biological applications of metal-based POM chemotherapeutic drugs to act as a neozoic radioprotectant.

Cerium oxide nanoparticles exert antitumor effects and enhance paclitaxel toxicity and activity against breast cancer cells

Cerium oxide nanoparticles (CeONPs) displayed cytotoxic properties against some cancer cells. However, there is very limited data about the possible antitumoral potential of them in breast cancer cells when used alone and/or together with a chemotherapeutic drug. We investigated the effects of CeONPs alone or in combination with paclitaxel (PAC) on healthy or carcinoma breast cells. After human breast cancer cells (MCF-7) treated with CeONPs alone or together with PAC for 24, 48, and 72 h, the effects of CeONPs on cell viability, apoptosis, migration, and adhesion were investigated. All cell viability and IC50 values of CeONPs and PAC treatments in healthy breast cells (HTERT-HME1) were higher than MCF-7 cells. They showed higher cytotoxicity against MCF-7 cells. CeONPs (10, 20, and 30 mM) and/or abraxane (AB) (2 μM) significantly decreased cell viability values in MCF-7 cells. All CeONPs concentrations increased the number of apoptotic MCF-7 cells. CeONPs (20 and 30 mM) alone or in combination with AB for 72 h treatment also significantly increased the apoptosis in compared to AB alone. CeONPs and/or AB can significantly inhibit the migratory ability of breast cancer cells. The migration rates in co-treated groups with CeONPs and AB were lower than CeONPs treatments. Higher concentrations of CeONPs alone or together with AB inhibited cell adhesion. Our results showed CeONPs can increase cytotoxicity and apoptosis and decrease cell migration and cell adhesion when used alone or together with AB. Therefore, combination of chemotherapeutics with CeONPs may provide a good strategy against cancer.

Metal Oxide Nanoparticles: Review of Synthesis, Characterization and Biological Effects

In the last few years, the progress made in the field of nanotechnology has allowed researchers to develop and synthesize nanosized materials with unique physicochemical characteristics, suitable for various biomedical applications. Amongst these nanomaterials, metal oxide nanoparticles (MONPs) have gained increasing interest due to their excellent properties, which to a great extent differ from their bulk counterpart. However, despite such positive advantages, a substantial body of literature reports on their cytotoxic effects, which are directly correlated to the nanoparticles' physicochemical properties, therefore, better control over the synthetic parameters will not only lead to favorable surface characteristics but may also increase biocompatibility and consequently lower cytotoxicity. Taking into consideration the enormous biomedical potential of MONPs, the present review will discuss the most recent developments in this field referring mainly to synthesis methods, physical and chemical characterization and biological effects, including the pro-regenerative and antitumor potentials as well as antibacterial activity. Moreover, the last section of the review will tackle the pressing issue of the toxic effects of MONPs on various tissues/organs and cell lines.

Radioprotective Effect of Nanocerium by Irradiation of Mice with Carbon Ions in Medium and Lethal Doses

The data of the study of the radioprotective properties of nanocerium (nCeO₂) after total irradiation of mice with carbon ions in medium and lethal doses according to the micronucleus test and the criterion of 30-day survival are presented. A significant protective effect of nCeO₂ upon irradiation at medium doses was observed at per os administration for 5 days before irradiation (that is, at long-term prophylactic use). Mouse survival data showed no protective effect of per os administration of nCeO₂ in contrast to the micronucleus test results. After injections of both nCeO₂ and saline solution 24 h before or immediately after irradiation, the radioprotective effect was detected using both methods. The data obtained revealed the dependence of the observed effects on the mode and time of nCeO₂ administration, the influence of the solvent, the level of doses and the quality of radiation, as well as demonstrated the possibility of using nanocerium preparations to protect organisms from radiation with high LET values and the importance of further studies of the radioprotective properties of new nanomaterials.

Enhanced Antioxidant Ability of PEG-Coated Ce0.5Zr0.5O2-Based Nanofluids for Scavenging Hydroxyl Radicals

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 CeO₂ and Ce_0.5Zr_0.5O₂ 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_0.5Zr_0.5O₂ is found to be 60%, which is significantly superior to that of CeO₂. 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 CeO₂ and Ce_0.5Zr_0.5O₂, 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_0.5Zr_0.5O₂ having an average size of ∼ 4 nm can be a potential antioxidant in relevant biomedical applications.

Acute Oral Administration of Cerium Oxide Nanoparticles Suppresses Lead Acetate-Induced Genotoxicity, Inflammation, and ROS Generation in Mice Renal and Cardiac Tissues

Lead, a highly toxic pollutant, causes numerous health problems and affects nearly all biological systems thus arousing interest in using antioxidants to reduce its toxic effects. Therefore, the undertaken study estimated the influence of cerium oxide nanoparticles (CeO2-NPs) on the lead acetate-induced genotoxicity and inflammation in the kidney and heart tissues of mice. Twenty male mice were randomly divided into negative control and lead acetate and/or CeO2-NPs administrated groups. Comet and diphenylamine assays were conducted to assess the DNA damage and the expression of apoptosis-related genes and inflammatory cytokines were also measured in addition to the estimation of reactive oxygen species (ROS) level. Co-administration of CeO2-NPs significantly reduced the DNA damage and ROS generation caused by lead acetate in the kidney and heart tissues. The co-administration of CeO2-NPs also ameliorated the lead acetate-induced dysregulation in the expression levels of p53, K-ras, interleukin-6, and cyclooxygenase-2 in the kidney and heart. Conclusion: the co-administration of CeO2-NPs suppresses the genotoxicity, inflammation, and ROS generation resulting from lead acetate administration and restoring the genomic DNA integrity; thus, administration of CeO2-NPs is recommended to minimize the lead acetate-induced hazards.

Application of Metal-Based Nanozymes in Inflammatory Disease: A Review

Reactive oxygen species (ROS) are metabolites of normal cells in organisms, and normal levels of ROS in cells are essential for maintaining cell signaling and other intracellular functions. However, excessive inflammation and ischemia-reperfusion can cause an imbalance of tissue redox balance, and oxidative stress occurs in a tissue, resulting in a large amount of ROS, causing direct tissue damage. The production of many diseases is associated with excess ROS, such as stroke, sepsis, Alzheimer’s disease, and Parkinson’s disease. With the rapid development of nanomedicine, nanomaterials have been widely used to effectively treat various inflammatory diseases due to their superior physical and chemical properties. In this review, we summarize the application of some representative metal-based nanozymes in inflammatory diseases. In addition, we discuss the application of various novel nanomaterials for different therapies and the prospects of using nanoparticles (NPs) as biomedical materials.

Antiviral nanopharmaceuticals: Engineered surface interactions and virus-selective activity

The COVID-19 pandemic has inspired large research investments from the global scientific community in the study of viral properties and antiviral technologies (e.g., self-cleaning surfaces, virucides, antiviral drugs, and vaccines). Emerging viruses are a constant threat due to the substantial variation in viral structures, limiting the potential for expanded broad-spectrum antiviral agent development, and the complexity of targeting multiple and diverse viral species with unique characteristics involving their virulence. Multiple, more infectious variants of SARS-CoV2 (e.g., Delta, Omicron) have already appeared, necessitating research into versatile, robust control strategies in response to the looming threat of future viruses. Nanotechnology and nanomaterials have played a vital role in addressing current viral threats, from mRNA-based vaccines to nanoparticle-based drugs and nanotechnology enhanced disinfection methods. Rapid progress in the field has prompted a review of the current literature primarily focused on nanotechnology-based virucides and antivirals. In this review, a brief description of antiviral drugs is provided first as background with most of the discussion focused on key design considerations for high-efficacy antiviral nanomaterials (e.g., nanopharmaceuticals) as determined from published studies as well as related modes of biological activity. Insights into potential future research directions are also provided with a section devoted specifically to the SARS-CoV2 virus. This article is categorized under: Toxicology and Regulatory Issues in Nanomediciney > Toxicology of Nanomaterials Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease.

Bioresponsive Nanomaterials: Recent Advances in Cancer Multimodal Imaging and Imaging-Guided Therapy

Cancer is a serious health problem which increasingly causes morbidity and mortality worldwide. It causes abnormal and uncontrolled cell division. Traditional cancer treatments include surgery, chemotherapy, radiotherapy and so on. These traditional therapies suffer from high toxicity and arouse safety concern in normal area and have difficulty in accurately targeting tumour. Recently, a variety of nanomaterials could be used for cancer diagnosis and therapy. Nanomaterials have several advantages, e.g., high concentration in tumour via targeting design, reduced toxicity in normal area and controlled drug release after various rational designs. They can combine with many types of biomaterials in order to improve biocompatibility. In this review, we outlined the latest research on the use of bioresponsive nanomaterials for various cancer imaging modalities (magnetic resonance imaging, positron emission tomography and phototacoustic imaging) and imaging-guided therapy means (chemotherapy, radiotherapy, photothermal therapy and photodynamic therapy), followed by discussing the challenges and future perspectives of this bioresponsive nanomaterials in biomedicine.

Advanced applications of cerium oxide based nanozymes in cancer

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO2 nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO2 nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease. In addition to that, CeO2 nanozymes have been widely used in the diagnosis and treatment of cancer. Many examples can be found in the literature, such as magnetic resonance detection, tumour marker detection, chemotherapy, radiotherapy, photodynamic therapy (PDT), and photothermal therapy (PTT). This review systematically summarises the latest applications of CeO2-based nanozymes in cancer research and treatment. We believe that this paper will help develop value-added CeO2 nanozymes, offering great potential in the biotechnology industry and with great significance for the diagnosis and treatment of a wide range of malignancies.

Anticancer Therapeutic Effects of Cerium Oxide Nanoparticles: Known and Unknown Molecular Mechanisms

Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO2), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular...

Redox Active Cerium Oxide Nanoparticles: Current Status and Burning Issues

Research on cerium oxide nanoparticles (nanoceria) has captivated the scientific community due to their unique physical and chemical properties, such as redox activity and oxygen buffering capacity, which made them available for many technical applications, including biomedical applications. The redox mimetic antioxidant properties of nanoceria have been effective in the treatment of many diseases caused by reactive oxygen species (ROS) and reactive nitrogen species. The mechanism of ROS scavenging activity of nanoceria is still elusive, and its redox activity is controversial due to mixed reports in the literature showing pro-oxidant and antioxidant activity. In light of its current research interest, it is critical to understand the behavior of nanoceria in the biological environment and provide answers to some of the critical and open issues. This review critically analyzes the status of research on the application of nanoceria to treat diseases caused by ROS. It reviews the proposed mechanism of action and shows the effect of surface coatings on its redox activity. It also discusses some of the crucial issues in deciphering the mechanism and redox activity of nanoceria and suggests areas of future research.

Internalized Nanoceria Modify the Radiation-Sensitivity Profile of MDA MB231 Breast Carcinoma Cells

Owing to its unique redox properties, cerium oxide (nanoceria) nanoparticles have been shown to confer either radiosensitization or radioprotection to human cells. We investigated nanoceria's ability to modify cellular health and reactive oxygen species (ROS) at various absorbed doses (Gray) of ionizing radiation in MDA-MB231 breast carcinoma cells. We used transmission electron microscopy to visualize the uptake and compartmental localization of nanoceria within cells at various treatment concentrations. The effects on apoptosis and other cellular health parameters were assessed using confocal fluorescence imaging and flow cytometry without and with various absorbed doses of ionizing radiation, along with intracellular ROS levels. Our results showed that nanoceria were taken up into cells mainly by macropinocytosis and segregated into concentration-dependent large aggregates in macropinosomes. Confocal imaging and flow cytometry data showed an overall decrease in apoptotic cell populations in proportion to increasing nanoparticle concentrations. This increase in cellular health was observed with a corresponding reduction in ROS at all tested absorbed doses. Moreover, this effect appeared pronounced at lower doses compared to unirradiated or untreated populations. In conclusion, internalized nanoceria confers radioprotection with a corresponding decrease in ROS in MDA-MB231 cells, and this property confers significant perils and opportunities when utilized in the context of radiotherapy.

Development and In Vitro Evaluation of Biocompatible PLA-Based Trilayer Nanofibrous Membranes for the Delivery of Nanoceria: A Novel Approach for Diabetic Wound Healing

The attempts to explore and optimize the efficiency of diabetic wound healing's promotors are still in progress. Incorporation of cerium oxide nanoparticles (nCeO2) in appropriate nanofibers (NFs) can prolong and maximize their promoting effect for the healing of diabetic wounds, through their sustained releases, as well as the nanofibers role in mimicking of the extra cellular matrix (ECM). The as-prepared nCeO2 were analyzed by using UV-Vis spectroscopy, XRD, SEM-EDX, TEM and FTIR, where TEM and SEM images of both aqueous suspension and powder showed spherical/ovoid-shaped particles. Biodegradable trilayer NFs with cytobiocompatibility were developed to sandwich nCeO2 in PVA NFs as a middle layer where PLA NFs were electrospun as outer bilayer. The nCeO2-loaded trilayer NFs were characterized by SEM, XRD, FTIR and DSC. A two-stage release behavior was observed when the nanoceria was released from the trilayer-based nanofibers; an initial burst release took place, and then it was followed by a sustained release pattern. The mouse embryo fibroblasts, i.e., 3T3 cells, were seeded over the nCeO2-loaded NFs mats to investigate their cyto-biocompatibility. The presence and sustained release of nCeO2 efficiently enhance the adhesion, growth and proliferation of the fibroblasts' populations. Moreover, the incorporation of nCeO2 with a higher amount into the designed trilayer NFs demonstrated a significant improvement in morphological, mechanical, thermal and cyto-biocompatibility properties than lower doses. Overall, the obtained results suggest that designated trilayer nanofibrous membranes would offer a specific approach for the treatment of diabetic wounds through an effective controlled release of nCeO2.

Nanoceria, the versatile nanoparticles: Promising biomedical applications

Nanotechnology has been a boon for the biomedical field due to the freedom it provides for tailoring of pharmacokinetic properties of different drug molecules. Nanomedicine is the medical application of nanotechnology for the diagnosis, treatment and/or management of the diseases. Cerium oxide nanoparticles (CNPs) are metal oxide-based nanoparticles (NPs) which possess outstanding reactive oxygen species (ROS) scavenging activities primarily due to the availability of "oxidation switch" on their surface. These NP have been found to protect from a number of disorders with a background of oxidative stress such as cancer, diabetes etc. In fact, the CNPs have been found to possess the environment-dependent ROS modulating properties. In addition, the inherent catalase, SOD, oxidase, peroxidase and phosphatase mimetic properties of CNPs provide them superiority over a number of NPs. Further, chemical reactivity of CNPs seems to be a function of their surface chemistry which can be precisely tuned by defect engineering. However, the contradictory reports make it necessary to critically evaluate the potential of CNPs, in the light of available literature. The review is aimed at probing the feasibility of CNPs to push towards the clinical studies. Further, we have also covered and censoriously discussed the suspected negative impacts of CNPs before making our way to a consensus. This review aims to be a comprehensive, authoritative, critical, and accessible review of general interest to the scientific community.

Cerium Oxide Nanoparticle Administration to Skeletal Muscle Cells under Different Gravity and Radiation Conditions

For their remarkable biomimetic properties implying strong modulation of the intracellular and extracellular redox state, cerium oxide nanoparticles (also termed "nanoceria") were hypothesized to exert a protective role against oxidative stress associated with the harsh environmental conditions of spaceflight, characterized by microgravity and highly energetic radiations. Nanoparticles were supplied to proliferating C2C12 mouse skeletal muscle cells under different gravity and radiation levels. Biological responses were thus investigated at a transcriptional level by RNA next-generation sequencing. Lists of differentially expressed genes (DEGs) were generated and intersected by taking into consideration relevant comparisons, which led to the observation of prevailing effects of the space environment over those induced by nanoceria. In space, upregulation of transcription was slightly preponderant over downregulation, implying involvement of intracellular compartments, with the majority of DEGs consistently over- or under-expressed whenever present. Cosmic radiations regulated a higher number of DEGs than microgravity and seemed to promote increased cellular catabolism. By taking into consideration space physical stressors alone, microgravity and cosmic radiations appeared to have opposite effects at transcriptional levels despite partial sharing of molecular pathways. Interestingly, gene ontology denoted some enrichment in terms related to vision, when only effects of radiations were assessed. The transcriptional regulation of mitochondrial uncoupling protein 2 in space-relevant samples suggests perturbation of the intracellular redox homeostasis, and leaves open opportunities for antioxidant treatment for oxidative stress reduction in harsh environments.

Establishment of anti-oxidation platform based on few-layer molybdenum disulfide nanosheet-coated titanium dioxide nanobelt nanocomposite

The nanozyme-based antioxidant system could protect normal cells from oxidative stress due to their reactive oxygen species (ROS) scavenging activity and good chemical stability. However, its use is limited for practical in vivo applications due to the high cost and poor biocompatibility (low catalytic efficiency). Herein, MoS₂ decorated on TiO₂ nanobelts (MoS₂@TiO₂) was prepared for antioxidation applications. The as-prepared MoS₂@TiO₂ heterostructure with 50 wt% MoS₂ showed the highest efficient catalase activity and superoxide dismutase (SOD) activity under normal physiological conditions. The composite was superior to its single component in terms of enhanced dispersibility and catalytic performance resulting from the higher surface specific area and more exposed active sites. MoS₂@TiO₂ was not only confirmed to have good in vitro and in vivo biocompatibility but can also effectively eliminate the endogenous excessive accumulation of ROS caused by oxidative stress using the fibroblast cell (L929) line as a model. Further experiments confirmed that in the established mouse oxidative stress model, MoS₂@TiO₂ can quickly restore the ROS to a normal level in the oxidative stress site of the mouse. These results indicated that MoS₂@TiO₂ enzyme-like nanomaterials can provide a huge therapeutic potential in future antioxidant defence applications.

Caffeic acid protects mice pancreatic islets from oxidative stress induced by multi-walled carbon nanotubes (MWCNTs)

Increasing applications of carbon nanotubes (CNTs) indicate the necessity to examine their toxicity. According to previous studies, CNTs caused oxidative stress that impaired β-cell functions and reduced insulin secretion. Our previous study indicated that single-walled carbon nanotubes (SWCNTs) could induce oxidative stress in pancreatic islets. However, there is no study on the effects of multi-walled carbon nanotubes (MWCNTs) on islets and β-cells. Therefore, the present study aims to evaluate effects of MWCNTs on the oxidative stress of islets and the protective effects of caffeic acid (CA) as an antioxidant. The effects of MWCNTs and CA on islets were investigated using MTT assay, reactive oxygen species (ROS), malondialdehyde (MDA), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), the content of glutathione (GSH) and mitochondrial membrane potential (MMP) and insulin secretion measurements. The lower viability of islet cells was dose-dependent due to the exposure to MWCNTs according to the MTT assay. Further studies revealed that MWCNTs decreased insulin secretion and MMP, induced ROS creation, increased the MDA level, and decreased activities of SOD, GSH-Px, CAT, and content of GSH. Furthermore, the pretreatment of islets with CA returned the changes. These findings indicated that MWCNTs might induce the oxidative stress of pancreatic islets occurring diabetes and protective CA effects that were mediated by the augmentation of the antioxidant defense system of islets. Our research suggested the necessity of conducting further studies on effects of MWCNTs and CA on the diabetes.

Rational Design of Nanomaterials for Various Radiation-Induced Diseases Prevention and Treatment

Radiation treatments often unfavorably damage neighboring healthy organs and cause a series of radiation sequelae, such as radiation-induced hematopoietic system diseases, radiation-induced gastrointestinal diseases, radiation-induced lung diseases, and radiation-induced skin diseases. Recently, emerging nanomaterials have exhibited good superiority for these radiation-induced disease treatments. Given this background, the rational design principle of nanomaterials, which helps to optimize the therapeutic efficiency, has been an increasing need. Consequently, it is of great significance to perform a systematic summarization of the advances in this field, which can trigger the development of new high-performance nanoradioprotectors with drug efficiency maximization. Herein, this review highlights the advances and perspectives in the rational design of nanomaterials for preventing and treating various common radiation-induced diseases. Furthermore, the sources, clinical symptoms, and pathogenesis/injury mechanisms of these radiation-induced diseases will also be introduced. Furthermore, current challenges and directions for future efforts in this field are also discussed.

Mechanisms for Tuning Engineered Nanomaterials to Enhance Radiation Therapy of Cancer

Engineered nanomaterials that produce reactive oxygen species on exposure to X- and gamma-rays used in radiation therapy offer promise of novel cancer treatment strategies. Similar to photodynamic therapy but suitable for large and deep tumors, this new approach where nanomaterials acting as sensitizing agents are combined with clinical radiation can be effective at well-tolerated low radiation doses. Suitably engineered nanomaterials can enhance cancer radiotherapy by increasing the tumor selectivity and decreasing side effects. Additionally, the nanomaterial platform offers therapeutically valuable functionalities, including molecular targeting, drug/gene delivery, and adaptive responses to trigger drug release. The potential of such nanomaterials to be combined with radiotherapy is widely recognized. In order for further breakthroughs to be made, and to facilitate clinical translation, the applicable principles and fundamentals should be articulated. This review focuses on mechanisms underpinning rational nanomaterial design to enhance radiation therapy, the understanding of which will enable novel ways to optimize its therapeutic efficacy. A roadmap for designing nanomaterials with optimized anticancer performance is also shown and the potential clinical significance and future translation are discussed.

The Effect of Cerium Oxide on Lung Tissue in Lower Extremity Ischemia Reperfusion Injury in Sevoflurane Administered Rats

INTRODUCTION

We aimed to investigate the effects of cerium oxide, applied before the sevoflurane anesthesia, on lung tissue in rats with lower extremity ischemia-reperfusion (IR).

MATERIALS AND METHODS

A total of 30 rats were randomly divided into five groups as; control (C), IR, cerium oxide-IR (CO-IR), IR-sevoflurane (IRS), and cerium oxide-IR-sevoflurane (CO-IRS). In the CO-IR group, 30 minutes after the injection of cerium oxide (0.5 mg/kg, intraperitoneal (i.p)), an atraumatic microvascular clamp was placed on the infrarenal abdominal aorta for 120 minutes. Then, the clamp was removed and reperfused for 120 minutes. Sevoflurane was applied in 100% oxygen at a rate of 2.3% at 4 L/min during IR. The blood samples were taken for biochemical analysis and the lung tissue samples were taken for histological analysis.

RESULTS

Neutrophil infiltration/aggregation was significantly higher in the IR group than in the C and CO-IRS groups. The alveolar wall thickness and total lung injury scores were significantly higher in the IR group than in the C, IRS, CO-IR and CO-IRS groups.

DISCUSSION

We determined that the administration of 0.5 mg/kg dose of cerium oxide with sevoflurane reduces the oxidative stress and corrects IR-related damage in lung tissue. Our results show that the administration of cerium oxide before IR and the administration of sevoflurane during IR have a protective effect in rats.

Exposure to nanoceria impacts larval survival, life history traits and fecundity of Aedes aegypti

Effectively controlling vector mosquito populations while avoiding the development of resistance remains a prevalent and increasing obstacle to integrated vector management. Although, metallic nanoparticles have previously shown promise in controlling larval populations via mechanisms which are less likely to spur resistance, the impacts of such particles on life history traits and fecundity of mosquitoes are understudied. Herein, we investigate the chemically well-defined cerium oxide nanoparticles (CNPs) and silver-doped nanoceria (AgCNPs) for larvicidal potential and effects on life history traits and fecundity of Aedes (Ae.) aegypti mosquitoes. When 3rd instar larvae were exposed to nanoceria in absence of larval food, the mortality count disclosed significant activity of AgCNPs over CNPs (57.8±3.68% and 17.2±2.81% lethality, respectively) and a comparable activity to Ag+ controls (62.8±3.60% lethality). The surviving larvae showed altered life history traits (e.g., reduced egg hatch proportion and varied sex ratios), indicating activities of these nanoceria beyond just that of a larvicide. In a separate set of experiments, impacts on oocyte growth and egg generation resulting from nanoceria-laced blood meals were studied using confocal fluorescence microscopy revealing oocytes growth-arrest at 16-24h after feeding with AgCNP-blood meals in some mosquitoes, thereby significantly reducing average egg clutch. AgCNPs caused ~60% mortality in 3rd instar larvae when larval food was absent, while CNPs yielded only ~20% mortality which contrasts with a previous report on green-synthesized nanoceria and highlights the level of detail required to accurately report and interpret such studies. Additionally, AgCNPs are estimated to contain much less silver (0.22 parts per billion, ppb) than the amount of Ag+ needed to achieve comparable larvicidal activity (2.7 parts per million, ppm), potentially making these nanoceria ecofriendly. Finally, this work is the first study to demonstrate the until-now-unappreciated impacts of nanoceria on life history traits and interference with mosquito egg development.

An overview on recent in vivo biological application of cerium oxide nanoparticles

Cerium oxide nanoparticles (CNPs) possess a great potential as therapeutic agents due to their ability to self-regenerate by reversibly switching between two valences +3 and +4. This article reviews recent articles dealing with in vivo studies of CNPs towards Alzheimer's disease, obesity, liver inflammation, cancer, sepsis, amyotrophic lateral sclerosis, acute kidney injury, radiation-induced tissue damage, hepatic ischemia reperfusion injury, retinal diseases and constipation. In vivo anti-cancer studies revealed the effectiveness of CNPs to reduce tumor growth and angiogenesis in melanoma, ovarian, breast and retinoblastoma cancer cell-induced mice, with their conjugation with folic acid, doxorubicin, CPM, or CXC receptor-4 antagonist ligand eliciting higher efficiency. After conjugation with triphenylphosphonium or magnetite nanoparticles, CNPs were shown to combat Alzheimer's disease by reducing amyloid-β, glial fibrillary acidic protein, inflammatory and oxidative stress markers in mice. By improving muscle function and longevity, the citrate/EDTA-stabilized CNPs could ameliorate amyotrophic lateral sclerosis. Also, they could effectively reduce obesity in mice by scavenging ROS and reducing adipogenesis, triglyceride synthesis, GAPDH enzyme activity, leptin and insulin levels. In CCl4-induced rats, stress signaling pathways due to inflammatory cytokines, liver enzymes, oxidative and endoplasmic reticulum messengers could be attenuated by CNPs. Commercial CNPs showed protective effects on rats with hepatic ischemia reperfusion and peritonitis-induced hepatic/cardiac injuries by decreasing oxidative stress and hepatic/cardiac inflammation. The same CNPs could improve kidney function by diminishing renal superoxide, hyperglycemia and tubular damage in peritonitis-induced acute kidney injury in rats. Radiation-induced lung and testicular tissue damage could be alleviated in mice, with the former showing improvement in pulmonary distress and bronchoconstriction and the latter exhibiting restoration in spermatogenesis rate and spermatid/spermatocyte number. Through enhancement of gastrointestinal motility, the CNPs could alleviate constipation in both young and old rats. They could also protect rat from light-induced retinal damage by slowing down neurodegenerative process and microglial activation.

Attenuation of Radiation-Induced Lung Injury by Hyaluronic Acid Nanoparticles

Purpose

Therapeutic thorax irradiation as an intervention in lung cancer has its limitations due to toxic effects leading to pneumonitis and/or pulmonary fibrosis. It has already been confirmed that hyaluronic acid (HA), an extracellular matrix glycosaminoglycan, is involved in inflammation disorders and wound healing in lung tissue. We examined the effects after gamma irradiation of hyaluronic acid nanoparticles (HANPs) applied into lung prior to that irradiation in a dose causing radiation-induced pulmonary injuries (RIPI).

Materials and Methods

Biocompatible HANPs were first used for viability assay conducted on the J774.2 cell line. For in vivo experiments, HANPs were administered intratracheally to C57Bl/6 mice 30 min before thoracic irradiation by 17 Gy. Molecular, cellular, and histopathological parameters were measured in lung and peripheral blood at days 113, 155, and 190, corresponding to periods of significant morphological and/or biochemical alterations of RIPI.

Results

Modification of linear hyaluronic acid molecule into nanoparticles structure significantly affected the physiological properties and caused long-term stability against ionizing radiation. The HANPs treatments had significant effects on the expression of the cytokines and particularly on the pro-fibrotic signaling pathway in the lung tissue. The radiation fibrosis phase was altered significantly in comparison with a solely irradiated group.

Conclusions

The present study provides evidence that application of HANPs caused significant changes in molecular and cellular patterns associated with RIPI. These findings suggest that HANPs could diminish detrimental radiation-induced processes in lung tissue, thereby potentially decreasing the extracellular matrix degradation leading to lung fibrosis.

Ceria-Containing Hybrid Multilayered Microcapsules for Enhanced Cellular Internalisation with High Radioprotection Efficiency

Cerium oxide nanoparticles (nanoceria) are believed to be the most versatile nanozyme, showing great promise for biomedical applications. At the same time, the controlled intracellular delivery of nanoceria remains an unresolved problem. Here, we have demonstrated the radioprotective effect of polyelectrolyte microcapsules modified with cerium oxide nanoparticles, which provide controlled loading and intracellular release. The optimal (both safe and uptake efficient) concentrations of ceria-containing microcapsules for human mesenchymal stem cells range from 1:10 to 1:20 cell-to-capsules ratio. We have revealed the molecular mechanisms of nanoceria radioprotective action on mesenchymal stem cells by assessing the level of intracellular reactive oxygen species (ROS), as well as by a detailed 96-genes expression analysis, featuring genes responsible for oxidative stress, mitochondrial metabolism, apoptosis, inflammation etc. Hybrid ceria-containing microcapsules have been shown to provide an indirect genoprotective effect, reducing the number of cytogenetic damages in irradiated cells. These findings give new insight into cerium oxide nanoparticles' protective action for living beings against ionising radiation.

Protection effect of cerium oxide nanoparticles against radiation-induced acute lung injuries in rats

INTRODUCTION

Radiation therapy is one of the most common tools for treating cancer. The aim is to deliver adequate doses of radiation to kill cancer cells and the most challenging part during this procedure is to protect normal cells from radiation. One strategy is to use a radioprotector to spare normal tissues from ionizing radiation effects. Researchers have pursued cerium oxide nanoparticles as a therapeutic agent, due to its diverse characteristics, which include antioxidant properties, making it a potential radioprotector.

MATERIALS AND METHODS

One hundred rats were divided into five groups of A) control group, intraperitoneal (IP) saline injection was done twice a week; B) bi-weekly IP injection of 14.5 nM (0.00001 mg/kg) CNP for two weeks; C) a single whole thorax radiation dose of 18 Gy; D) a single whole thorax radiation dose of 18 Gy + bi-weekly injection of 14.5 nM CNP for two weeks after radiation; E) bi-weekly IP injection of 14.5 nM CNP for two weeks prior to radiation + a single whole thorax radiation dose of 18 Gy. Thirty days after irradiation, 7 rats from each group were anesthetized and their lungs extracted for histopathological examination.

RESULTS

Statistical analyses revealed that CNP significantly decreased the incidence of tissue collapse and neutrophile aggregation in rats receiving CNP before radiation in comparison with the radiation group.

CONCLUSION

The results suggested the possibility of using CNP as a future radioprotector due to its ability to protect normal cells against radiation-induced damage.

Dancing with reactive oxygen species generation and elimination in nanotheranostics for disease treatment

Reactive oxygen species (ROS) play important roles in cell signaling and tissue homeostasis, in which the level of ROS is critical through the equilibrium between ROS generating and eliminating events. A disruption of the balance leads to disease development either by a surplus or a dearth of ROS, which requires ROS-modulating strategies to overturn the defect for disease treatment. Over the past decade, there have been tremendous advances in nanomedicine centering ROS generation and/or elimination as major mechanisms to treat a variety of diseases. In this review, we will discuss the research achievements on two opposite approaches of ROS-generating and ROS-eliminating strategies for treating cancer and other related diseases. Importantly, we will highlight the conceptual and strategic advances of ROS-mediated immunomodulation, including macrophage polarization, immunogenic cell death and T cell activation, which are currently rising as one of the mainstreams of cancer therapy. At the end, the future challenges and opportunities of mediating ROS-based mechanisms are envisioned. In light of the pleiotropic roles of ROS in different diseases, we hope this review is timely to deliver a clear logic of designing principles on ROS generation and elimination for different disease treatments.

Cerium oxide nanoparticles: A promising tool for the treatment of fibrosarcoma in-vivo

In this study, we used cerium oxide nanoparticles and evaluated their anti-cancer effects in a mouse model of fibrosarcoma. For evaluation of anti-cancer effects of nanoceria, tumor volume measurement, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay, quantitative real-time PCR (qPCR) for Bax and Bcl2 genes, a panel of liver and kidney function tests and hematoxylin-eosin staining were done. Nanoceria dominantly accumulated in the tumor and it could significantly decrease tumor growth and volume in tumor-bearing mice that received nanoceria for four weeks. Cerium oxide nanoparticle showed potential anti-cancer properties against fibrosarcoma.

Dislocation Engineered PtPdMo Alloy With Enhanced Antioxidant Activity for Intestinal Injury

Radiotherapy is the mainstay for abdomen and pelvis cancers treatment. However, high energy ray would inflict gastrointestinal (GI) system and adversely disrupt the treatment. The anti-oxidative agents provide a potential route for protecting body from radiation-induced injuries. Herein, highly catalytic nanocubes with dislocation structure are developed for treatment of intestinal injury. Structural and catalytic properties show that Mo incorporation can enhance antioxidant activity by dislocation structure in the alloy. In vitro studies showed that PtPdMo improved cell survival by scavenging radiation-induced ROS accumulation. Furthermore, after animals were exposed to lethal dose of radiation, the survival was increased by 50% with the PtPdMo i.p. treatment. Radioprotection mechanism revealed that PtPdMo alleviated the oxidative stress in multi-organs especially the small intestine by inhibiting intestinal epithelium apoptosis, reducing DNA strands breaks and enhancing repairing ability. In addition, PtPdMo protected hematopoietic system by improving the number of bone marrow and peripheral blood cells.

Cerium Aminoclay-A Potential Hybrid Biomaterial for Anticancer Therapy

In this study, novel biomedical properties of Ce-aminoclay (CeAC) were investigated through in vitro and in vivo assays. CeAC (≥500 μg/mL) can selectively kill cancer cells (A549, Huh-1, AGS, C33A, HCT116, and MCF-7 cells) while leaving most normal cells unharmed (WI-38 and CCD-18Co cells). Notably, it displayed a high contrast of simultaneous imaging in HeLa cells by blue photoluminescence without any fluorescence dye. Its anticancer mechanism has been fully demonstrated through apoptosis assays; herein CeAC induced high-level apoptosis (16%), which promoted the expression of proapoptotic proteins (Bax, p53, and caspase 9) in tumor cells. Besides, its biological behavior was determined through antitumor effects using intravenous and intratumoral administration routes in mice implanted with HCT116 cells. During a 40 day trial, the tumor volume and tumor weight were reduced by a maximum of 92.24 and 86.11%, respectively. The results indicate that CeAC exhibits high bioavailability and therapeutic potential based on its unique characteristics, including high antioxidant capacity and electrostatic interaction between its amino functional groups and the mucosal surface of cells. In summary, it is suggested that CeAC, with its high bioimaging contrast, can be a promising anticancer agent for future biomedical applications.