The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

Ain, Qura Tul; Haq, Samina Hyder; Alshammari, Abeer; Almutlaq, Moudhi; Anjum, Muhammad Naeem

doi:10.3762/bjnano.10.91

Cited by 162 publications

(83 citation statements)

References 54 publications

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“…On the basis of X‐ray diffraction (XRD), as shown in Figure 2b, it can be concluded that all samples are basically X‐ray amorphous, and only for FeNC phen a small diffraction peak at 2 θ = 26.6° related to the graphite (002) crystal phase was detected after prolonged data acquisition. [ 51 ]…”

Section: Resultsmentioning

confidence: 99%

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy

Gallenkamp

Paul

et al. 2021

Adv Energy and Sustain Res

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FeNC catalysts are the most promising substitutes for Pt‐based catalysts for the oxygen reduction reaction in proton exchange fuel cells. However, it remains unclear which FeN4 moieties contribute to the reaction mechanism and in which way. The origin of this debate could lie in various preparation routes, and therefore the aim of this work is to identify whether the active site species differ in different preparation routes or not. To answer this question, three FeNC catalysts, related to the three main preparation routes, are prepared and thoroughly characterized. Three transitions A–C that are distinguished by a variation in the local environment of the deoxygenated state are defined. By in situ 57Fe Mössbauer spectroscopy, it can be shown that all three catalysts exhibit a common spectral change assigned to one of the transitions that constitutes the dominant contribution to the direct electroreduction of oxygen. Moreover, the change in selectivity can be attributed to the presence of a variation within additional species. Density functional theory calculations help to explain the observed trends and enable concrete suggestions on the nature of nitrogen coordination in the two FeN4 moieties involved in the oxygen reduction reaction of FeNC catalysts.

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Section: Resultsmentioning

confidence: 99%

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy

Gallenkamp

Paul

et al. 2021

Adv Energy and Sustain Res

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“…A sharp peak at around 1725 cm −1 , which is assigned to C=O stretching vibrations, demonstrated the presence of carbonyl and carboxyl groups [ 30 , 39 ]. An absorption band at ≈1616 cm −1 appears owing to the stretching of cyclic alkene (C=C) from unoxidized graphitic domain [ 30 , 40 , 41 ]. Additionally, the presence of ethers is evidenced by the appearance of strong absorption bands at around 1160 cm −1 and 1040 cm −1 , which are assigned to C−O stretching vibrations, and through epoxides exhibiting C−O bending vibrations at around 878 cm −1 [ 39 ].…”

Section: Resultsmentioning

confidence: 99%

Near-Infrared Radiation-Based Mild Photohyperthermia Therapy of Non-Melanoma Skin Cancer with PEGylated Reduced Nanographene Oxide

et al. 2020

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Using a one-step thermal reduction and non-covalent chemical functionalization process, PEGylated reduced nanographene oxide (rGOn-PEG) was produced from nanographene oxide (GOn) and characterized in terms of particle size, dispersion stability, chemistry, and photothermal properties, in view of its use for photothermal therapy (PTT) of non-melanoma skin cancer. GOn infrared spectrum presented more intense bands assigned to oxygen containing functional groups than observed for rGOn-PEG. GOn C/O ratio decreased more than 50% comparing with rGOn-PEG and nitrogen was present in the latter (N at % = 20.6) due to introduction of PEG-NH2. Thermogravimetric analysis allowed estimating the amount of PEG in rGOn-PEG to be of about 56.1%. Simultaneous reduction and PEGylation increased the lateral dimensions from 287 ± 139 nm to 521 ± 397 nm, as observed by transmission electron microscopy and dynamic light scattering. rGOn-PEG exhibited ≈13-fold higher absorbance in the near-infrared radiation (NIR) region, as compared to unmodified GOn. Low power (150 mW cm−2) NIR irradiation using LEDs resulted in rGOn-PEG heating up to 47 °C, which is within the mild PTT temperature range. PEGylation strongly enhanced the dispersibility of rGOn in physiological media (phosphate buffered saline, fetal bovine serum, and cell culture medium) and also improved the biocompatibility of rGOn-PEG, in comparison to GOn (25–250 μg mL−1). After a single NIR LED irradiation treatment of 30 min, a decrease of ≈38% in A-431 cells viability was observed for rGOn-PEG (250 μg mL−1). Together, our results demonstrate the potential of irradiating rGOn-PEG using lower energy, cheaper, smaller, and safer LEDs, as alternative to high power lasers, for NIR mild hyperthermia therapy of cancer, namely non-melanoma skin cancer.

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“…A peak was evident at around 1725 cm −1 in both GO and GOn spectra, which is assigned to C=O stretching vibrations, demonstrating the presence of carbonyl and carboxyl groups [ 3 , 14 , 20 ]. The stretching of cyclic alkene (C=C) was observed at approximately 1610 cm −1 , which results from the unoxidized graphitic backbone [ 20 , 21 , 22 ]. C−O stretching vibrations attributed to ethers were present at around 1140 and 1020 cm −1 , and C−O bending vibrations of epoxides were found at around 858 cm −1 [ 3 , 14 ].…”

Section: Resultsmentioning

confidence: 99%

High-Yield Production of Nano-Lateral Size Graphene Oxide by High-Power Ultrasonication

et al. 2021

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Nanographene oxide (GOn) constitutes a nanomaterial of high value in the biomedical field. However, large scale production of highly stable aqueous dispersions of GOn is yet to be achieved. In this work, we explored high-power ultrasonication as a method to reduce particle size of GO and characterized the impact of the process on the physicochemical properties of the material. GOn was obtained with lateral dimensions of 99 ± 43 nm and surface charge of −39.9 ± 2.2 mV. High-power ultrasonication enabled an improvement of stability features, particularly by resulting in a decrease of the average particle size, as well as zeta potential, in comparison to GO obtained by low-power exfoliation and centrifugation (287 ± 139 nm; −29.7 ± 1.2 mV). Remarkably, GOn aqueous dispersions were stable for up to 6 months of shelf-time, with a global process yield of 74%. This novel method enabled the production of large volumes of highly concentrated (7.5 mg mL−1) GOn aqueous dispersions. Chemical characterization of GOn allowed the identification of characteristic oxygen functional groups, supporting high-power ultrasonication as a fast, efficient, and productive process for reducing GO lateral size, while maintaining the material’s chemical features.

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The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

Cited by 162 publications

References 54 publications

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy

Near-Infrared Radiation-Based Mild Photohyperthermia Therapy of Non-Melanoma Skin Cancer with PEGylated Reduced Nanographene Oxide

High-Yield Production of Nano-Lateral Size Graphene Oxide by High-Power Ultrasonication

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The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

Cited by 162 publications

References 54 publications

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ57Fe Mössbauer Spectroscopy

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ57Fe Mössbauer Spectroscopy

Near-Infrared Radiation-Based Mild Photohyperthermia Therapy of Non-Melanoma Skin Cancer with PEGylated Reduced Nanographene Oxide

High-Yield Production of Nano-Lateral Size Graphene Oxide by High-Power Ultrasonication

Contact Info

Product

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Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy

Active Site Identification in FeNC Catalysts and Their Assignment to the Oxygen Reduction Reaction Pathway by In Situ⁵⁷Fe Mössbauer Spectroscopy