Bio-based synthesis of Nano-Ceria and evaluation of its bio-distribution and biological properties

Cerium oxide nanoparticles: Synthesis methods and applications in wound healing

Wound care and treatment can be critical from a clinical standpoint. While different strategies for the management and treatment of skin wounds have been developed, the limitations inherent in the current approaches necessitate the development of more effective alternative strategies. Advances in tissue engineering have resulted in the development of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO2 NPs, the biological properties of CeO2 NPs, the role of CeO2 NPs in wound healing, the use of scaffolds containing CeO2 NPs for wound healing applications, and the potential toxicity of CeO2 NPs.

Green synthesis of cerium oxide nanoparticles using zucchini peel extract for cytotoxic and photocatalytic properties

The aim of this study is the green synthesis of cerium oxide nanoparticles (CeO₂-NPs) using a natural capping agent and its application in water and wastewater treatment. This study presents the biosynthesis of CeO₂-NPs by the exertion of a green method using zucchini (Cucurbita pepo) extract as a capping agent. Synthesized CeO₂-NPs were distinguished through TGA/DTA, FT-IR, XRD, FESEM/TEM and EDX/PSA, and DRS procedures. According to the XRD pattern of NPs, the crystallinity structure was a face-centered cubic (fcc) with an Fm3m space group and the size was estimated at 30 nm. The spherical morphology of NPs was confirmed through FESEM/TEM images. In the following, the photocatalytic property of NPs was investigated by the decolorization of methylene blue (MB) dye within UV-A light. Also, the cytotoxicity of NPs on the CT26 cell line was evaluated through the MTT test, and no toxicity was observed in the results, which indicates their biocompatibility.

Nanoceria: an innovative strategy for cancer treatment

Nanoceria or cerium oxide nanoparticles characterised by the co-existing of Ce³⁺ and Ce⁴⁺ that allows self-regenerative, redox-responsive dual-catalytic activities, have attracted interest as an innovative approach to treating cancer. Depending on surface characteristics and immediate environment, nanoceria exerts either anti- or pro-oxidative effects which regulate reactive oxygen species (ROS) levels in biological systems. Nanoceria mimics ROS-related enzymes that protect normal cells at physiological pH from oxidative stress and induce ROS production in the slightly acidic tumour microenvironment to trigger cancer cell death. Nanoceria as nanozymes also generates molecular oxygen that relieves tumour hypoxia, leading to tumour cell sensitisation to improve therapeutic outcomes of photodynamic (PDT), photothermal (PTT) and radiation (RT), targeted and chemotherapies. Nanoceria has been engineered as a nanocarrier to improve drug delivery or in combination with other drugs to produce synergistic anti-cancer effects. Despite reported preclinical successes, there are still knowledge gaps arising from the inadequate number of studies reporting findings based on physiologically relevant disease models that accurately represent the complexities of cancer. This review discusses the dual-catalytic activities of nanoceria responding to pH and oxygen tension gradient in tumour microenvironment, highlights the recent nanoceria-based platforms reported to be feasible direct and indirect anti-cancer agents with protective effects on healthy tissues, and finally addresses the challenges in clinical translation of nanoceria based therapeutics.

The Anticancer Role of Cerium Oxide Nanoparticles by Inducing Antioxidant Activity in Esophageal Cancer and Cancer Stem-Like ESCC Spheres

Introduction

Esophagus squamous cell carcinoma (ESCC) has a poor prognosis, a high rate of metastasis, and rapid clinical progression. One hypothesis is that therapeutic failure is due to the presence of cancer stem cells (CSC). Previous studies showed the anticancer effect of cerium oxide nanoparticles (CNP) in different cancer cells. In this study, we aim to evaluate the effect of cerium oxide nanoparticles on cell antioxidants, toxicity, as well as cell oxidant level in esophageal cancer (YM1) and cancer stem cell-like (CSC-LC) cell lines.

Method

YM1 and CSC-LC spheres were treated with CNP at different concentrations. The cell viability was assessed by using the MTT test. Antioxidant levels (SOD (superoxide dismutase, CAT (catalase), thiol, and TAC (total antioxidant capacity)), antioxidant genes expression (SOD and CAT), ROS (reactive oxygen species), and MDA (malondialdehyde) levels were assessed in both cell lines.

Results

CSC-LC had significantly elevated SOX4 and OCT4 pluripotent genes. The ROS and MDA levels were significantly reduced in both YM1 and CSC-LC spheres after treatment with CNP. Also, the antioxidant levels and expressions were elevated significantly in both cell lines after CNP treatment.

Conclusion

These results suggest the potential anticancer effect of CNP by elevating antioxidant levels and expressions, and reducing oxidant levels.

Cerium oxide decorated 5-fluorouracil loaded chitosan nanoparticles for treatment of hepatocellular carcinoma

Reactive oxygen species (ROS) play a crucial role in the mammalian system in both normal and pathological conditions. Hence, this work prepared and characterized the ROS responsive cerium oxide nanoparticles (CeO₂ NPs) decorated 5-fluorouracil (5FU) loaded chitosan (CS) nanoparticles (CS-5FU NPs) for enhanced anticancer activity in hepatocellular carcinoma (HepG2 cells). CeO₂ NPs decorated CS-5FU NPs were found to be spherical in shape and black dense aggregated particles sized 200 nm. The functional properties and cubic crystalline structure of CeO₂ NPs were studied by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis, respectively. Further, CS-5FU-CeO₂ NPs attenuated the 2,2'-Azobis (2-methylpropionamidine) dihydrochloride (AAPH) induced ROS formation in mouse embryonic fibroblasts (NIH3T3 cells) while enhancing apoptotic cell death in HepG2 cells by controlled delivery of 5FU. Furthermore, CS-5FU-CeO₂ NPs have not exhibited toxicity to red blood cells (RBCs) and chick chorioallantoic membrane (CAM). Hence, this work concluded that CeO₂ NPs decorated CS-5FU NPs synergistically enhanced anticancer activity in HepG2 cells through the regulation of ROS.

Nanostructured Ceria: Biomolecular Templates and (Bio)applications

Ceria (CeO2) nanostructures are well-known in catalysis for energy and environmental preservation and remediation. Recently, they have also been gaining momentum for biological applications in virtue of their unique redox properties that make them antioxidant or pro-oxidant, depending on the experimental conditions and ceria nanomorphology. In particular, interest has grown in the use of biotemplates to exert control over ceria morphology and reactivity. However, only a handful of reports exist on the use of specific biomolecules to template ceria nucleation and growth into defined nanostructures. This review focusses on the latest advancements in the area of biomolecular templates for ceria nanostructures and existing opportunities for their (bio)applications.

Different approaches to synthesising cerium oxide nanoparticles and their corresponding physical characteristics, and ROS scavenging and anti-inflammatory capabilities

The biological applications of cerium oxide nanoparticles (nanoceria) have received extensive attention in recent decades. The coexistence of trivalent cerium and tetravalent cerium on the surface of nanoceria allows the scavenging of reactive oxygen species (ROS). The regeneratable changes between Ce3+ and Ce4+ make nanoceria a suitable therapeutic agent for treating ROS-related diseases and inflammatory diseases. The size, morphology and Ce3+/Ce4+ state of cerium oxide nanoparticles are affected by the synthesis method. This review focuses on various synthesis methods of cerium oxide nanoparticles and discusses their corresponding physical characteristics, and anti-ROS and anti-inflammatory properties.

Green-synthesized CeO2 nanoparticles for photocatalytic, antimicrobial, antioxidant and cytotoxicity activities

Cerium oxide nanoparticles (CeO2 NPs) are a sought-after material in numerous fields due to their potential applications such as in catalysis, cancer therapy, photocatalytic degradation of pollutants, sensors, polishing agents. Green synthesis usually involves the production of CeO2 assisted by organic extracts obtained from plants, leaves, flowers, bacteria, algae, food, fruits, etc. The phytochemicals present in the organic extracts adhere to the NPs and act as reducing and/or oxidizing agents and capping agents to stabilize the NPs, modify the particle size, morphology and band gap energy of the as-synthesized materials, which would be advantageous for numerous applications. This review focuses on the green extract-mediated synthesis of CeO2 NPs and discusses the effects on CeO2 NPs of various synthesis methods that have been reported. Several photocatalytic, antimicrobial, antioxidant and cytotoxicity applications have been evaluated, compared and discussed. Future prospects are also suggested.

Synthesis and characterization of nanoceria for electrochemical sensing applications

Nanoceria (cerium oxide nanoparticles: CeO2-NPs) has received significant attention due to its biocompatibility, good conductivity, and the ability to transfer oxygen. Nanoceria has been widely used to develop electrochemical sensors and biosensors as it could increase response time, sensitivity, and stability of the sensor. In this review, we discussed synthesis methods, and the recent applications employing CeO2-NPs for electrochemical detection of various analytes reported in the most recent four years.

The Advances of Ceria Nanoparticles for Biomedical Applications in Orthopaedics

The ongoing biomedical nanotechnology has intrigued increasingly intense interests in cerium oxide nanoparticles, ceria nanoparticles or nano-ceria (CeO2-NPs). Their remarkable vacancy-oxygen defect (VO) facilitates the redox process and catalytic activity. The verification has illustrated that CeO2-NPs, a nanozyme based on inorganic nanoparticles, can achieve the anti-inflammatory effect, cancer resistance, and angiogenesis. Also, they can well complement other materials in tissue engineering (TE). Pertinent to the properties of CeO2-NPs and the pragmatic biosynthesis methods, this review will emphasize the recent application of CeO2-NPs to orthopedic biomedicine, in particular, the bone tissue engineering (BTE). The presentation, assessment, and outlook of the orthopedic potential and shortcomings of CeO2-NPs in this review expect to provide reference values for the future research and development of therapeutic agents based on CeO2-NPs.

Template Synthesis of Porous Ceria-Based Catalysts for Environmental Application

Porous oxide materials are widely used in environmental catalysis owing to their outstanding properties such as high specific surface area, enhanced mass transport and diffusion, and accessibility of active sites. Oxides of metals with variable oxidation state such as ceria and double oxides based on ceria also provide high oxygen storage capacity which is important in a huge number of oxidation processes. The outstanding progress in the development of hierarchically organized porous oxide catalysts relates to the use of template synthetic methods. Single and mixed oxides with enhanced porous structure can serve both as supports for the catalysts of different nature and active components for catalytic oxidation of volatile organic compounds, soot particles and other environmentally dangerous components of exhaust gases, in hydrocarbons reforming, water gas shift reaction and photocatalytic transformations. This review highlights the recent progress in synthetic strategies using different types of templates (artificial and biological, hard and soft), including combined ones, in the preparation of single and mixed oxide catalysts based on ceria, and provides examples of their application in the main areas of environmental catalysis.

Synthesis of Cerium Oxide Nanoparticles Using Various Methods: Implications for Biomedical Applications

Cerium oxide nanoparticles have been used in a number of non-medical products over the years. The therapeutic application of these nanoparticles has mainly been due to their oxidative stress ameliorating abilities. Their enzyme-mimetic catalytic ability to change between the Ce3+ and Ce4+ species makes them ideal for a role as free-radical scavengers for systemic diseases as well as neurodegenerative diseases. In this review, we look at various methods of synthesis (including the use of stabilizing/capping agents and precursors), and how the synthesis method affects the physicochemical properties, their behavior in biological environments, their catalytic abilities as well as their reported toxicity.