Functionalized Cerium Oxide Nanoparticles Research Articles

Geniposide and Harpagoside Functionalized Cerium Oxide Nanoparticles as a Potential Neuroprotective.

Alzheimer's disease is associated with protein aggregation, oxidative stress, and the role of acetylcholinesterase in the pathology of the disease. Previous investigations have demonstrated that geniposide and harpagoside protect the brain neurons, and cerium nanoparticles (CeO2 NPs) have potent redox and antioxidant properties. Thus, the effect of nanoparticles of Ce NPs and geniposide and harpagoside (GH/CeO2 NPs) on ameliorating AD pathogenesis was established on AlCl3-induced AD in mice and an aggregation proteins test in vitro. Findings of spectroscopy analysis have revealed that GH/CeO2 NPs are highly stable, nano-size, spherical in shape, amorphous nature, and a total encapsulation of GH in cerium. Treatments with CeO2 NPs, GH/CeO2 NPs, and donepezil used as positive control inhibit fibril formation and protein aggregation, protect structural modifications in the BSA-ribose system, have the ability to counteract Tau protein aggregation and amyloid-β1-42 aggregation under fibrillation condition, and are able to inhibit AChE and BuChE. While the GH/CeO2 NPs, treatment in AD induced by AlCl3 inhibited amyloid-β1-42, substantially enhanced the memory, the cognition coordination of movement in part AD pathogenesis may be alleviated through reducing amyloidogenic pathway and AChE and BuChE activities. The findings of this work provide important comprehension of the chemoprotective activities of iridoids combined with nanoparticles. This could be useful in the development of new therapeutic methods for the treatment of neurodegenerative diseases.

Influence of Eu3+ Doping on Physiochemical Properties and Neuroprotective Potential of Polyacrylic Acid Functionalized Cerium Oxide Nanoparticles.

Cerium oxide nanoparticles (CeONPs) exhibiting antioxidant properties are investigated as potential tools for neurodegenerative diseases. Here, we synthesized polyacrylic acid conjugated cerium oxide (CeO) nanoparticles, and further to enhance their neuroprotective effect, Eu3+ was substituted at different concentrations (5, 10, 15 and 20 mol%) to the CeO, which can also impart fluorescence to the system. CeONPs and Eu-CeONPs in the size range of 15-30 nm were stable at room temperature. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed the chemical state of Eu and Ce components, and we could conclude that all Eu3+ detected on the surface is well integrated into the cerium oxide lattice. The emission spectrum of Eu-CeO arising from the 7F0 → 5D1 MD and 7F0 → 5D2 transitions indicated the Eu3+ ion acting as a luminescence center. The fluorescence of Eu-CeONPs was visualized by depositing them at the surface of positively charged latex particles. The developed nanoparticles were safe for human neuronal-like cells. Compared with CeONPs, Eu-CeONPs at all concentrations exhibited enhanced neuroprotection against 6-OHDA, while the protection trend of Eu-CeO was similar to that of CeO against H2O2 in SH-SY5Y cells. Hence, the developed Eu-CeONPs could be further investigated as a potential theranostic probe.

An all-in-one portable colorimetric detection platform for sensitive detection of bisphenol A based on target-mediated CeO2@ZIF-8/Apt biocomposites

BPA aptamers functionalized cerium oxide nanoparticles encapsulated in zeolitic imidazolate framework-8 (CeO2@ZIF-8/Apt) were developed to fabricate an all-in-one portable platform for on-site quantitative detection of BPA. By combining biocomposites with a 3,3′,5,5′-tetramethylbenzidine (TMB)-based sodium alginate (SA) hydrogel and smartphone-based RGB analysis, highly sensitive and convenient monitoring of BPA was achieved. CeO2@ZIF-8 composites were constructed using a novel surfactant-modified concentration-controlled synthesis strategy. After being functionalized with BPA aptamers, CeO2@ZIF-8/Apt biocomposites were used as target-response colorimetric probes for target recognition and signal transduction. The oxidase-like activity of CeO2@ZIF-8 was effectively sealed by BPA aptamers and controllably released in a concentration-dependent manner through aptamer-BPA reactions. Utilizing SA hydrogels containing TMB in the caps, a one-step sample addition and one-pot detection can be conveniently achieved and reliably quantified by smartphone-based RGB analysis in an instrument-free way. The detection range of this portable detection platform is 50 pg/mL to 500 ng/mL with limit of detection calculated as 34.88 pg/mL, comparable to that of conventional detection in the solution system (4.57 pg/mL). The recoveries in tap water, apple juice, and milk ranged from 91.02 % and 106.75 %. This work contributes new insights into the design of all-in-one detection platforms for contaminants monitoring in resource-constrained regions.

Performance evaluation of phosphonium based deep eutectic solvents coated cerium oxide nanoparticles for CO2 capture

The critical challenge being faced by our current modern society on a global scale is to reduce the surging effects of climate change and global warming, being caused by anthropogenic emissions of CO2 in the environment. Present study reports the surface driven adsorption potential of deep eutectic solvents (DESs) surface functionalized cerium oxide nanoparticles (CeNPs) for low pressure CO2 separation. The phosphonium based DESs were prepared using tetra butyl phosphoniumbromide as hydrogen bond acceptor (HBA) and 6 acids as hydrogen bond donors (HBDs). The as-developed DESs were characterized and employed for the surface functionalization of CeNPs with their subsequent utilization in adsorption-based CO2 adsorption. The synthesis of as-prepared DESs was confirmed through FTIR measurements and absence of precipitates, revealed through visual observations. It was found that DES6 surface functionalized CeNPs demonstrated 27% higher adsorption performance for CO2 capturing. On the contrary, DES3 coated CeNPs exhibited the least adsorption progress for CO2 separation. The higher adsorption performance associated with DES6 coated CeNPs was due to enhanced surface affinity with CO2 molecules that must have facilitated the mass transport characteristics and resulted an enhancement in CO2 adsorption performance. Carboxylic groups could have generated an electric field inside the pores to attract more polarizable adsorbates including CO2, are responsible for the relatively high values of CO2 adsorption. The quadruple movement of the CO2 molecules with the electron-deficient and pluralizable nature led to the enhancement of the interactive forces between the CO2 molecules and the CeNPs decorated with the carboxylic group hydrogen bond donor rich DES. The current findings may disclose the new research horizons and theoretical guidance for reduction in the environmental effects associated with uncontrolled CO2 emission via employing DES surface coated potential CeNPs.

Biosynthesis of phyto functionalized cerium oxide nanoparticles mediated from Scoparia dulsis L. for appraisal of anti-cancer potential against adenocarcinomic lung cancer cells and paracetamol sensing potentiality.

This research work aims at the eco-friendly preparation of cerium oxide nanoparticles (CeSD NPs) utilizing the natural extract of Scoparia dulsis L. An attempt was made to analyze the influence of the fuel load on the size, shape, and optical properties of the nanoparticles. The p-XRD studies revealed the controlled formation of NPs with a size not more than 12.74nm. The surface area studies appraise the mesoporous nature of the synthesized ceria particles, with the maximum specific surface area of 36.06 m2g-1. The nano-regime CeO2 nanoparticles had a definite impact on biomedical and electrochemical studies. The CeSD NPs with minuscule size (10.69nm) manifested promising antioxidant and human RBC protection activity. The antioxidant properties were evaluated using % DPPH inhibition with of maximum of 83.38. The stabilization of RBC's by CeSD NPs was maximum at 94.97%. However, the CeSD NPs with apparent size (12.74nm) that utilized greater volume fuel (25mL) had noticeable results on adenocarcinomic lung (A549) cancer cell viability and antidiabetic study which was maximum of 70.16% at concentration 500μg/mL. A satisfactory antibacterial application was proffered against chosen bacterial stains. The smallest size CeO2 NPs exhibited the best proton diffusion coefficient (8.16 × 10-6 cm2s-1), and the capacitance values of the CeSD NPs are near in all samples (~ 1.17 to 2.00 F) manifest their compact nano-regime sizes. The paracetamol drug was chosen as analyte to appreciating the superlative efficiency for sensing paracetamol drug with the lowest detection limit.

Highly stretchable polyurethane coating based on functionalized cerium oxide nanoparticles for anti‐corrosive/UV protection

AbstractTo prolong the active life of carbon steel in corrosive environment, it is an effective way to use inorganic nano‐pigments in polyurethane (PU) coatings. In this work, the CeO2 nanoparticles are modified by APTMS (labeled as mCeNPs), and the organic–inorganic nanocomposite coating is prepared. The morphology and structure of PU/mCeNPs composites are characterized by field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The mechanical and UV resistance properties of compound material are studied by ultraviolet spectroscopy and universal tensile testing machine. The corrosion resistance of PU/mCeNPs coatings are investigated by Tafel polarization technique and electrochemical impedance spectroscopy. The results show that the PU composite coating with mCeNPs additive had high long‐term corrosion resistance. Under the optimum conditions, when mCeNPs accounted for 5% of PU, the nanocomposite coatings show excellent UV resistance, excellent mechanical properties, and long‐term corrosion resistance due to the characteristics of ceria and its good dispersion in PU.

Ionic Liquid Functionalised Nanoparticles Based Tanning System as a Less Chrome Tanning Approach

Nanoparticles due to their size and high reactivity towards collagen provide potential applications in the tanning process. The current study aims to investigate the potential of ionic liquid functionalized cerium oxide nanoparticles as a combination tanning agent with minimum utilization of the chromium. The experimental results indicate that the presence of nanoparticles increases the thermal stability from 62°C to 92°C. The physical strength and organoleptic characteristics of the nanoparticles-BCS tanned leather are on par with conventional chrome tanned leather. Antibacterial studies reveal that the leather tanned with nanoparticles shows improved antibacterial activity. Thus, nanoparticle based tanning system invokes a considerable array of interest as an alternative tanning process with minimal and efficient usage of chromium.

Polyethylene glycol functionalized cerium oxide nanoparticle confer protection against UV- induced oxidative damage in skin: evidences for a new class of UV filter

Acute exposure to high dose of ultraviolet (UV) radiations is known to cause significant harm to skin, primarily due to the generation of free radicals and damage to DNA, which often culminate in rapid aging of the skin, or cancers. Keratinocytes being the most abundant skin’s cells are affected most by UV. Although a degree of endogenous protection is present, the vulnerability of UV-induced damaged can be minimized using protective agents. A few UV filters (organic and inorganic) have been successfully commercialized, yet, due to prevailing disadvantages such as low solubility, photostability, and aesthetic sense, suitable and more efficient UV filters continue to be explored as potential ingredients of cosmaceutical agents. A recently studied antioxidant enzyme mimetic cerium oxide nanoparticles showed emerging piece of evidence on benefits under environmental stress. However, its protective abilities as potential UV filter and therefore applicability in cosmaceutical has not yet been completely explored. This study provides a piece of evidence in support of beneficial effects of this new class of UV filters, polyethyleneglycol functionalized nanoceria (PEG-CNP) against UV - induced damage in vitro and in vivo. The nanomolar concentration of PEG-CNPs in the cell culture showed significant protection from UV exposure, by direct ROS scavenging, the rescue of cells from cell cycle arrest and DNA damage. Further, a proof of the concept study in dehaired rat skin showed that the topical application of 50 μM PEG-CNPs prevented the initial signs of UV induced damage. Unlike conventional UV filters, PEG-CNPs confer protection by internalizing the cells, and scavenging the radicals.

Fibro-porous PLLA/gelatin composite membrane doped with cerium oxide nanoparticles as bioactive scaffolds for future angiogenesis.

Functionalized cerium oxide nanoparticle (CeNP)-loaded fibro-porous poly-l-lactic acid (PLLA)/gelatin composite membranes were prepared via an electrospinning technology. Considering the importance of such membrane scaffolds for promoting angiogenesis in tissue engineering and drug screening, a series of PLLA/gelatin composite fiber membranes loaded with different doses of CeNPs was prepared. The prepared composite membranes demonstrated hydrophilicity, water absorption, and improved mechanical properties compared to a PLLA and PLLA/gelatin membrane. Also, cell viability assay using somatic hybrid endothelial cells (EA.hy926) proved the biocompatible nature of the scaffolds. The biocompatibility was further supported by in vivo chick embryo angiogenesis assay using fertilized eggs. Our initial results support that these membrane scaffolds could be useful for angiogenesis-related disease treatment after further investigations.

Functionalized cerium oxide nanoparticles mitigate the oxidative stress and pro-inflammatory activity associated to the portal vein endothelium of cirrhotic rats

Background and aimsThe occurrence of endothelial alterations in the liver and in the splanchnic vasculature of cirrhotic patients and experimental models of liver diseases has been demonstrated. However, the pathological role of the portal vein endothelium in this clinical context is scarcely studied and, therefore, deserves attention. In this context, we aimed to investigate whether pathological endothelial activation occurs in the portal vein of cirrhotic rats.MethodsCirrhosis was induced in wistar rats by CCl4 inhalation. We generated immortalized endothelial cells from the portal vein of control (CT-iPVEC) and cirrhotic rats (CH-iPVEC) by retroviral transduction of the SV40 T antigen. We assessed differential gene expression and intracellular reactive oxygen species (ROS) levels in iPVECs and in portal veins of control and cirrhotic rats. Finally, we assessed the therapeutic effectiveness of cerium oxide nanoparticles (CeO2NP) on reversing PVEC activation and macrophage polarization.ResultsCH-iPVECs overexpressed collagen-I, endothelin-1, TIMP-1, TIMP-2, IL-6 and PlGF genes. These results were consistent with the differential expression showed by whole portal veins from cirrhotic rats. In addition, CH-iPVECs showed a significant increase in intracellular ROS and the capacity of potentiating M1 polarization in macrophages. The treatment of CH-iPVECs with CeO2NPs blocked intracellular ROS formation and IL-6 and TIMP-2 gene overexpression. In agreement with the in vitro results, the chronic treatment of cirrhotic rats with CeO2NPs also resulted in the blockade of both ROS formation and IL-6 gene overexpression in whole portal veins.ConclusionsEndothelial cells from portal vein of cirrhotic rats depicted an abnormal phenotype characterized by a differential gene expression and the induction of M1 polarization in macrophages. We identified the excess of intracellular reactive oxygen species (ROS) as a major contributor to this altered phenotype. In addition, we demonstrated the utility of the nanomaterial cerium oxide as an effective antioxidant capable of reverse some of these pathological features associated with the portal vein in the cirrhosis condition.

Antiamyloid activity of functionalized cerium oxide nanoparticle on lysozyme fibrillation: Spectroscopic and microscopic investigation

Accumulation of amyloid fibrils of proteins in different organs is a pathological indication for various neurogenerative disorders. Recently nanotechnology is at the centre of interest to tackle with those disorders. In this study we have chosen hen egg white lysozyme as our model protein which is responsible for hereditary systemic Amyloidosis disease. Here we have reported effect of cerium oxide nanoparticle (CeONP), folic acid functionalized CeONP (FA-CeONP) and polyacrylic acid functionalized CeONP (PAA-CeONP) (all of them having size ∼18 nm) on fibrillation of hen egg white lysozyme (Lyz). The amyloid growth is monitored by Thioflavin T (ThT), Congo Red (CR), 8-anilinonapthalene-1-sulfonic acid (ANS) assay, time resolved fluorescence anisotropy, intrinsic fluorescence, circular dichroism, atomic force microscopy and fluorescence microscopy study. Results demonstrate that all nanoparticle (NP) shows antiamyloid activity by broadening lag phase and suppressing growth phase of Lyz amyloid growth, but PAA-CeONP shows maximum inhibitory effect. These bare and functionalized CeONP shows dose dependent antiamyloid activity. We have also demonstrated that such inhibition of amyloid formation is associated with reduction of β-sheet content of protein. The inhibition efficiency is quantified by half maximal inhibition concentration IC50 values. A mechanistic pathway is explained on the basis of electrostatic interaction between NP and Lyz by ζ- potential measurement. This interaction is also analyzed theoretically by docking analysis. Thus our study provides a basis for use of CeONP as a promising candidate in therapeutic application in amyloid related disorders.

Surface engineering of polystyrene–cerium oxide nanocomposite thin films for refractive index enhancement

Polymer nanocomposites have gained much importance in the field of optoelectronics due to their unique optical properties. Refractive index engineering using nanoparticles is an effective strategy that could be applied for the fabrication of optical devices. Herein, we report three different strategies which are employed to enhance the refractive index of polymer thin films. These include incorporating cerium oxide nanoparticles onto the polystyrene matrix, secondly adding cerium oxide nanoparticles onto the cross-linkable polystyrene and thirdly by embedding functionalized cerium oxide nanoparticles onto the cross-linkable polystyrene. Refractive index of the polystyrene thin films was enhanced by dispersing neat CeO2 nanoparticles and functionalized CeO2 nanoparticles into the polystyrene matrix. 1.38% enhancement in the refractive index of the polymer nanocomposite thin films could be achieved using our technique. The blending of polystyrene with cerium oxide nanoparticle presents a prospective way to engineer the refractive index of polymer thin films. We firmly believe that the study will be an effective guide towards future research in the area of surface engineering of polymer thin films for refractive index enhancement.

Antiamyloid Activity of Functionalized Cerium Oxide Nanoparticle on Lysozyme Fibrillation: Spectroscopic and Microscopic Investigation

Accumulation of amyloid fibrils of proteins in different organs is a pathological indication for various neurogenerative disorders. Recently nanotechnology is at the centre of interest to tackle with those disorders. In this study we have chosen hen egg white lysozyme as our model protein which is responsible for hereditary systemic Amyloidosis disease. Here we have reported effect of Cerium oxide nanoparticle (CeONP), folic acid functionalized CeONP (FA-CeONP) and polyacrylic acid functionalized CeONP (PAA-CeONP) (all of them having size ~18 nm) on fibrillation of hen egg white lysozyme (Lyz). The amyloid growth is monitored by Thioflavin T (ThT), Congo Red (CR), 8-anilinonapthalene-1-sulfonic acid (ANS) assay, time resolved fluorescence anisotropy, intrinsic fluorescence, circular dichroism, atomic force microscopy and fluorescence microscopy study. Results demonstrate that all nanoparticle (NP) shows antiamyloid activity by broadening lag phase and suppressing growth phase of Lyz amyloid growth, but PAA-CeONP shows maximum inhibitory effect. These bare and functionalized CeONP shows dose dependent antiamyloid activity. We have also demonstrated that such inhibition of amyloid formation is associated with reduction of s-sheet content of protein. The inhibition efficiency is quantified by half maximal inhibition concentration IC50 values. A mechanistic pathway is explained on the basis of electrostatic interaction between NP and Lyz by ζ- potential measurement. This interaction is also analyzed theoretically by docking analysis. Thus our study provides a basis for use of CeONP as a promising candidate in therapeutic application in amyloid related disorders.

Attachment of a Frog Skin-Derived Peptide to Functionalized Cerium Oxide Nanoparticles

Peptide Brevinin-2R (B2R) has derived from frog skin secretions and possesses cytotoxic effects on cancer cells. Beside, cerium oxide nanoparticle (CNP) has antioxidant properties and could be used in anticancer studies. The purpose of this study is to investigate antioxidant and cytotoxicity of cerium oxide nanoparticle conjugated with B2R. First, cerium oxide nanoparticles were amine functionalized and peptide attached to it through establishment of peptide bond. Then, (1,1-diphenyl-2-picrylhydrazyl) DPPH and 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activities of CNP-B2R were determined. MTT assay were used in order to compare cytotoxicity of CNP- B2R on two different cell lines. HFLF-pI5 cell and A549 cell lines were selected as representative of normal and cancer cells, respectively. Also, the cytotoxic effects of CNP, B2R and CNP-B2R were investigated on A549 cell line. Results of antioxidant evaluations showed that the antioxidant activity of CNP-Peptide increased at higher concentration of CNP-B2R with IC50 of 0.2 and 0.54 (mg/mL) for DPPH and ABTS assays, respectively. The results of cytotoxicity effects showed that CNP-B2R was more potent in killing tumor cell line in comparison with normal cell line. Cytotoxicity of CNP, B2R and CNP-B2R demonstrated that CNP-B2R and B2R had the lower cell viability effects compared to CNP. Our findings showed cytotoxicity of CNP-B2R against cancer cell lines in comparison with normal cells indicating the potential anticancer properties of CNP-B2R.

Folic acid conjugated amine functionalized cerium oxide nanoparticle for cancer targeted gene therapy

Event Abstract Back to Event Folic acid conjugated amine functionalized cerium oxide nanoparticle for cancer targeted gene therapy Kishor Sarkar1, Harini V. Krishnan1, G Vinoth Kumar2, K Suresh Babu2, Vinayak Sant1 and Shilpa Sant1, 3, 4 1 University of Pittsburgh, Department of Pharmaceutical Sciences, United States 2 Pondicherry University, Centre for Nano Science and Technology, India 3 University of Pittsburgh, Department of Bioengineering, United States 4 University of Pittsburgh, McGowan Institute for Regenerative Medicine, United States Introduction: Gene therapy has become alternative therapeutic approach to treat genetic diseases such as cancer[1]. Nonviral vectors have gained tremendous attraction over the viral vector due to its low toxicity, non-immunogenicity and low production cost[2]-[4]. Recently, rare earth metal oxide especially cerium oxide nanoparticle (CNP) has widely been used in biomedical fields such as drug delivery, bio-imaging, nanomedicine and tissue engineering application because of its inherent antioxidant activity, free radical scavenging activity and radioprotection to normal cell[5],[6]. It is also reported that CNP increased the ROS (reactive oxygen species) in cancer cell[7]. Therefore, we hypothesized that therapeutic gene (like siRNA, p53 etc.) delivery by means of CNP may give the dual therapeutic effect in conjugation with increased ROS level in cancer cell for the treatment of cancer. Here we report the functionalization of CNP by low molecular weight polyethyleneimine (LPEI, 2 kDa) followed by conjugation of folic acid (FA) for targeted gene delivery. Methods: LPEI was conjugated with CNP (LPEI-conj-CNP) through carboxylation followed by amidation reaction. Then, FA was reacted with LPEI-conj-CNP by carbodiimide to get FA-LPEI-conj- CNP. CNP/pDNA (enhanced green fluorescent protein, EGFP encoding pDNA) complexes were prepared at various weight ratios and characterized by agarose gel electrophoresis assay and dynamic light scattering (DLS). In vitro transfection efficiency, toxicity, ROS and underlying mechanistic pathway were also evaluated in HeLa cell. Results: Poor water dispersibility of CNP at physiological pH is a major drawback for biological field especially gene/ drug delivery application. CNP forms stable dispersion in acidic pH only. Despite the positive zeta potential of CNP, it did not bind any DNA at any weight ratio due to poor dispersibility. But, the DNA complexation capability of CNP significantly increased after conjugation of LPEI and LPEI-conj-CNP complexed all pDNA at a very low weight ratio of 0.5:1. Due to presence of lots of primary amine groups in LPEI, the water dispersibility of CNP increased drastically and resulted better DNA complexation through the cationic primary amine groups. The transfection efficiency of CNP increased after conjugation of LPEI but the efficiency increased significantly after FA conjugation with LPEI-conj-CNP. FA-LPEI-conj-CNP/pDNA complex at weight ratio of 15:1 showed highest transfection efficiency which also surpassed the efficiency offered by PEI (25 kDa) (Figure 1). It was also observed that FA-LPEI-conj-CNP internalized into cell via folate receptor as well as caveolae mediated pathway and resulted enhanced transfection efficiency. While LPEI-conj-CNP followed clathrin mediated pathway followed by lysosomal compartment entrapment and as a result showed low transfection efficiency. It was found that green fluorescence (fluorescent dichlorofluorescein, DCF obtained through oxidation of nonfluorescent dichlorofluorescein diacetate, DCFA by ROS) increased drastically by FA-LPEI-conj-CNP compared to all CNPs and H2O2 treated cell indicating the increase in ROS (Figure 2). Conclusion: The transfection efficiency as well as ROS of CNP increased after functionalization of CNP especially after FA conjugation. Therefore, FA-LPEI-conj-CNP may be useful candidate in nonviral gene therapy for cancer treatment by using its dual property including gene delivery and ROS enhancement. This work was financially supported by Start-up funds from University of Pittsburgh School of Pharmacy

Core-shell effects of functionalized oxide nanoparticles inside long-range meso-ordered spray-dried silica spheres

Core-shell and homogeneous distributions of functionalized cerium oxide nanoparticles within spray-dried mesostructured silica spheres are achieved by modification of synthesis parameters such as the templating agent and nanoparticle capping functions.