Effect Of Graphene Oxide Nanoparticles Research Articles

Fluorescent nanoplastics increase the toxic effects of Graphene oxide nanoparticles in freshwater algae Scenedesmus obliquus

The increased usage of Graphene oxide (GO) in various industrial applications led to their entry into freshwater systems. Other secondary contaminants like nanoplastics (NPs) often co-exist with GO in the environment. This study examines the possible role of fluorescent nanoplastics (FNPs) in modifying the toxic effects of GO on freshwater algae Scenedesmus obliquus. Selected concentrations of GO (0.1, 1, and 10 mg L−1) were combined with a fixed concentration of FNPs (1 mg L−1) to perform combinational toxicity tests on algae. FNPs significantly enhanced the toxic effects of GO in the mixtures in comparison with the pristine GO. In addition to the cytotoxic effects, oxidative stress parameters like total ROS generation and malondialdehyde (MDA) production also increased in the case of the combined pollutants. The antioxidant enzymatic activities like catalase (CAT) and superoxide dismutase (SOD) in the cells were also assessed. Algal exposure to the pristine pollutants and their mixture led to a notable decrease in photosynthetic activities in the cells, with the mixed pollutants aggravating the loss of activity. The interactive toxic effects of the contaminants when present in mixtures were evaluated using Abbotts' Independent action modelling. Furthermore, optical microscopic images revealed the morphological changes in the algal cells after exposure to the contaminants both in the pristine and combined forms.

The effects of graphene oxide nanoparticles on the mechanical and thermal properties of polyurethane/polycaprolactone nanocomposites; a molecular dynamics approach

Using molecular dynamics simulations using LAMMPS and other tools, this work examined the effect of graphene oxide nanoparticles on the mechanical and thermal properties (TPs) of polyurethane/polycaprolactone nanocomposites. The simulations examined the atomic, MP, and thermodynamic properties of atomic structures while examining and equilibrating them. After 10 ns of equilibration at 300 K and 1 bar, samples were convergent and the simulation parameters were confirmed. The addition of GO-NPs significantly enhanced TPs and MPs, with optimal improvements observed at a 2 % concentration. Specifically, increasing GO-NP content from 0.5 % to 2 % resulted in increases in heat flux from 680.95 to 714.09 W/m2, thermal conductivity from 0.69 to 0.93 W/m·K, and Young's modulus from 5.91 to 6.63 MPa. This is while increasing GO-NP content from 0.5 % to 2 % resulted in decreases in both the mean square displacement and glass transition temperature (Temp) to 0.22 Å2and 318 K, respectively. However, further increasing the GO-NP concentration to 5 % led to a decrease in HF and TC, likely due to nanoparticle agglomeration, which also reduced mechanical strength and increased MSD and Tg. This study underscores the importance of optimizing GO-NP concentration, with 2 % identified as the most effective for enhancing the properties of PU/PCL/GO-NCs.

Graphene oxide nanoparticles inhibit H9N2 influenza A virus infectivity by destroying viral coat proteins.

Nanoparticles have gained attention as potential antiviral agents, but the effects of graphene oxide nanoparticles (GONPs) on influenza virus remain unclear. In this study, we evaluated the antiviral activity of GONPs against influenza virus strain A/Hunan-Lengshuitan/11197/2013(H9N2). Our results show that GONPs with a diameter of 4 nm exerted an antiviral effect, whereas those with a diameter of 400 nm had no effect. Treatment with 4-nm GONPs reduced viral titers by more than 99% and inhibited viral nucleoprotein expression in a dose-dependent manner. We also confirmed that 4-nm GONPs inhibited the infectivity of H9N2 in MDCK cells. A transmission electron microscopic analysis revealed morphological abnormalities in the GONP-treated virus, including the destruction of the envelope glycoprotein spikes and an irregular shape, suggesting that GONPs cause the destruction of the viral coat proteins. Our results highlight the potential utility of GONPs in the prevention and treatment of viral infections, especially those of emerging and re-emerging viruses.

Mitigative Effect of Graphene Oxide Nanoparticles in Maintaining Gut–Liver Homeostasis against Alcohol Injury

Alcoholic liver disease (ALD) develops when the immunotolerant environment of the liver is compromised due to excessive alcohol consumption. ALD progression involves variations in the expressions of multiple genes, resulting in liver inflammation and the development of a leaky gut. It is still unclear which molecular mechanism is involved in ALD progression, and due to that, there are currently no FDA-approved drugs available for its treatment. In this study, the protective effects of graphene oxide (GO) nanoparticles were investigated against ethanol-induced damage in the gut–liver axis in in vitro. GO was synthesized using a modified Hummer’s method, and characterization was performed. Given the general concerns regarding nanoparticle toxicity, assessments of cell viability, lipid accumulation, DNA damage, cell death, and the generation of reactive oxygen species (ROS) were conducted using various techniques. Furthermore, the gene expressions of pro- and anti-inflammatory cytokines were determined using RT-qPCR. The findings reveal that GO promoted cell viability even against ethanol treatment. Additionally, lipid accumulation significantly decreased when cells were treated with GO alongside ethanol compared to ethanol treatment alone, with similar trends observed for other assays. A gene expression analysis indicated that GO treatment reduced the expression of proinflammatory cytokines while enhancing the expression of antioxidant genes. Moreover, GO treatment led to improvements in gut integrity and a reduction in proinflammatory cytokines in colon cells damaged by ethanol. These findings suggest that GO holds promise as a drug carrier, exhibiting no observed toxic effects. By shedding light on the protective effects of GO against ethanol-induced damage, this study contributes to the burgeoning field of nanoparticle-mediated therapy for ALD.

Immunogenic and toxic effects of graphene oxide nanoparticles in mouse skeletal muscles and human red blood cells

To investigate immunogenic and toxic effects of graphene oxide (GO) nanoparticles in mouse skeletal muscles and in human blood in vitro. GO nanoparticles prepared using a probe sonicator were supended in deionized H2O or PBS, and particle size and surface charge of the nanoparticles were measured with dynamic light scattering (DLS). Different concentrations (0.5, 1.0 and 2.0 mg/mL) of GO suspension or PBS were injected at multiple sites in the gastrocnemius muscle (GN) of C57BL/6 mice, and inflammatory response and immune cell infiltrations were detected with HE and immunofluorescence staining. We also examined the effects of GO nanoparticles on human red blood cell (RBC) morphology, hemolysis and blood coagulation using scanning electron microscope (SEM), spectrophotometry, and thromboelastography (TEG). GO nanoparticles suspended in PBS exhibited better colloidal dispersity, stability and surface charge effects than those in deionized H2O. In mouse GNs, injection of GO suspensions dose- and time-dependently resulted in sustained muscular inflammation and myofiber degeneration at the injection sites, which lasted till 8 weeks after the injection; immunofluorescence staining revealed obvious infiltration of monocytes, macrophages, dendritic cells and CD4+ T cells around the injection sites in mouse GNs. In human RBCs, incubation with GO suspensions at 0.2, 2.0 and 20 mg/mL, but not at 0.002 or 0.02 mg/mL, caused significant alterations of cell morphology and hemolysis. TEG analysis showed significant abnormalities of blood coagulation parameters following treatment with high concentrations of GO. GO nanoparticles can induce sustained inflammatory and immunological responses in mouse GNs and cause RBC hemolysis and blood coagulation impairment, suggesting its muscular toxicity and hematotoxicity at high concentrations.

Investigation of the effect of graphene oxide nanoparticles on the structural and dielectric parameters in zinc oxide semiconductors

In this study, pure and 1%, 3% and 5% doped graphene oxide (GO) reinforced zinc oxide (ZnO) nanoparticles were synthesized by sol-gel method. The aim was to improve the electrical and dielectric properties of ZnO semiconductor metal oxide used in many electronic, optoelectronic and electrochemical technologies. FE-SEM, X-ray diffraction (XRD), Raman spectroscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy (FT-IR), were used to show the structural and morphological properties of the synthesized ZnO and GO doped ZnO nanoparticles. Impedance analysis was used to study the dielectric properties of the produced nanoparticles. XRD analysis revealed typical peaks of nGO and ZnO nanoparticles. Through the FE-SEM and XRD analysis, it was shown that the ZnO and GO nanopowders were successfully synthesized. The results revealed that ZnO-GO nanoparticles, having good dielectric constant with loss and AC conductivity values, such materials can be a good candidate for solar cells and photovoltaic devices.Graphical

Effects of Graphene Oxide Nanoparticles on Delamination in CFRP and Optimization Using Response Surface Modeling

AbstractCarbon fiber composites recently have captured the attention of many for their wide array of properties surpassing those of traditional metals. Carbon fiber‐reinforced plastic (CFRP) has several excellent properties like a high strength‐to‐weight ratio, better chemical resistance, and other strength characteristics. But one problem affecting the use of CFRP is its delamination. This occurs during drilling holes for various operations. It is a known fact that the aircraft industry is one such industry very much dependent on such drilling operations. Failures such as fiber rupture, surface irregularities, micro‐crack formation, and deformations around drilling regions are commonly encountered during the machining of CFRP composite. This research has studied the effects of graphene oxide nanoparticles on delamination in the drilling of CFRP composite. Carbon fiber is manufactured using a vacuum bag process. The optimum conditions for the drilling process are found by using response surface modeling (RSM) which leads to minimum delamination in CFRP fabricated.

Effect of graphene oxide nanoparticles on in vitro growth of Fragaria x ananassa (Cameron Highlands white Strawberry) and evaluation of genetic stability using DAMD and ISSR markers

Graphene oxide (GO) is a novel nanomaterial with distinct physical properties and significant biological applications. The use of GO in plant tissue culture offers several new properties and potential applications. This research is vital due to the growing need for innovative techniques to promote plant growth, improve plant productivity and mitigate challenges posed by environmental stressors. This study focused on the rare Cameron Highlands white strawberry plants (Fragaria x ananassa) and addressed issues such as callus production during direct shoot induction and hyperhydricity. The research aimed to investigate the effects of GO on the regeneration process and genetic stability of white strawberry plants and to use molecular markers to ensure that plants propagated in vitro are true to type. For this purpose, shoot tip explants were used and different concentrations of GO (0, 2.5, 5.0, 7.5, 10 mg/L) were added to the Murashige and Skoog (MS) medium for six weeks. The results showed that the optimum concentration for promoting the development of white strawberry seedlings was 7.5 mg/L of GO. The study also revealed that the addition of 7.5 mg/L GO in combination with 8 μM TDZ to the MS medium facilitated the induction of multiple shoots. Moreover, the clonal fidelity of the in vitro plants treated with GO showed a genetic similarity of over 97%. These results confirm that lower GO concentrations improve plant development and stability. Consequently, this nanomaterial has a positive effect on the growth of strawberry plants and is therefore well suited for strawberry tissue culture.

Multigenerational Effects of Graphene Oxide Nanoparticles on Acheta domesticus DNA Stability.

The use of nanoparticles like graphene oxide (GO) in nanocomposite industries is growing very fast. There is a strong concern that GO can enter the environment and become nanopollutatnt. Environmental pollutants' exposure usually relates to low concentrations but may last for a long time and impact following generations. Attention should be paid to the effects of nanoparticles, especially on the DNA stability passed on to the offspring. We investigated the multigenerational effects on two strains (wild and long-lived) of house cricket intoxicated with low GO concentrations over five generations, followed by one recovery generation. Our investigation focused on oxidative stress parameters, specifically AP sites (apurinic/apyrimidinic sites) and 8-OHdG (8-hydroxy-2'-deoxyguanosine), and examined the global DNA methylation pattern. Five intoxicated generations were able to overcome the oxidative stress, showing that relatively low doses of GO have a moderate effect on the house cricket (8-OHdG and AP sites). The last recovery generation that experienced a transition from contaminated to uncontaminated food presented greater DNA damage. The pattern of DNA methylation was comparable in every generation, suggesting that other epigenetic mechanisms might be involved.

Effect of graphene oxide nanoparticles on apoptosis of T-lymphocytes and Jurkat cells

Graphene and its derivatives are materials with unique physicochemical properties. A detailed study of these materials allows to consider them prospective biomedical agents for targeted drug and gene delivery, photothermal therapy of cancer, bioimaging, etc. However, this requires a comprehensive studies of their effects on the body tissues, including cells of the immune system.
 The aim of our research was to stydy the effects of nanoparticles based on pegylated graphene oxide (GO) upon apoptosis of T lymphocytes derived from blood of healthy donors and Jurkat 5332 cell line. Comparison of these cells will extend our knowledge of the effects of nanomaterials on the cells, and to respond the question, what results obtained with continuous cell lines are valid for normal non-malignant cells. In this work, we used GO nanoparticles (100-200 nm, 1-5 m) coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol (PEG). The cells were cultured for 24 hours at 37 C and 5% CO2with nanoparticles at concentrations of 5 and 25 g/mL. Viability and early and late apoptosis of incubated Jurkat cells and CD3+cells from healthy donors were assessed by flow cytometry. It was found that the small nanoparticles coated with linear PEG at high concentrations (25 g/mL) could significantly reduce the number of live cells and increase the number of cells in late apoptosis. At the same time, large nanoparticles coated with branched PEG at high concentrations (25 g/mL) increased the percentage of T cells in early apoptosis.
 Meanwhile, the GO nanoparticles at both concentrations did not affect the viability and apoptosis of Jurkat cells, regardless of the size, concentration, and type of surface function of the particles.
 The obtained results suggest that GO nanoparticles exert different effects upon normal and malignant lymphocytes of T lineage. One may assume that these discrepancies could be explained by greater resistance of tumor cells compared to normal T cells. These findings suggests that studies of nanomaterials upon living cells should not be limited to experiments on cell lines, since their properties may significantly differ from those of non-malignant cells.

Investigating the anticancer and anti-angiogenic effects of graphene oxide nanoparticles containing 6-gingerol modified with chitosan and folate

Abstract Objective The use of nanocarriers to improve the targeting of treatment plays a key role in the treatment of many diseases, including cancer. This study was carried out to synthesize graphene oxide (GO) containing 6-gingerol (Ging) modified with chitosan (CS)-folic acid (FA) nanoparticles (Ging-GO-CS-FA) to improve the anti-cancer effects of Ging. Methods After the synthesis of nanoparticles, the average size, surface charge, and dispersion index (DPI) of nanoparticles were analyzed by the dynamic light scattering (DLS) method. Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FTIR) were utilized to assess the morphology and functional groups of synthesized nanoparticles, respectively. The 2,5-diphenyl-2H-tetrazolium bromide (MTT) method was performed to assess the toxicity effect of nanoparticles on different types of cancer cells. The antioxidant power of nanoparticles was evaluated by ABTS and DPPH methods. In addition, the chorioallantoic membrane (CAM) test was conducted to investigate the anti-angiogenic effects of nanoparticles. Finally, the real-time quantitative PCR (qPCR) method was carried out to detect the changes in the expression of angiogenic and antioxidant genes in cancer cells. Results The nanoparticles have an average size of 73.21 nm, a DPI of 0.27, and a surface charge of 29.5. The encapsulation rate of Ging in nanoparticles was reported to be 81.7%. According to the MTT test, the most sensitive cell line to the Ging-GO-CS-FA nanoparticles was reported to be gastric cancer cells (IC50 ~ 27). The results of the antioxidant test showed the high antioxidant power of nanoparticles in the laboratory environment by inhibiting ABTS and DPPH free radicals. The pro-oxidant power of Ging-GO-CS-FA against cancer cells was confirmed by reducing the amount of the superoxide dismutase (SOD) gene in the treated cells. The decreasing effects of Ging-GO-CS-FA on angiogenesis were observed by reducing the average length, the number of blood vessels, average height, and weight of treated embryos. In addition, the decrease in the expression of VEGF and VEGF-R genes confirmed the anti-angiogenic of Ging-GO-CS-FA. Conclusions These results show the promising effect of Ging-GO-CS-FA on gastric cancer cells by inhibiting angiogenesis and increasing the level of oxidants.

Graphene oxide-induced, reactive oxygen species-mediated mitochondrial dysfunctions and apoptosis: high-dose toxicity in normal cells.

Aim: The cytotoxic effects of graphene oxide nanoparticles (GONPs) using MTT assays, observance of apoptotic markers, and oxidative stress were outlined. Materials & methods: Rat embryonic fibroblasts (REFs) and human epithelial breast cells (HBLs) were used at 250, 500 and 750μg/ml concentrations. Results: Significant cytotoxic and apoptotic effects were observed. Analyses of CYP2E1 and malondialdehyde concentrations in REF and HBL-100 cell lines after exposing to GONPs confirmed the nanomaterials toxicity. However, the glutathione levels in REF and HBL-100 cell lines showed a substantial reduction compared with the control. The cytochrome CYP2E1, glutathione, malondialdehyde and caspase-3 alterations provided a plausible interlinked relationship. Conclusion: The study confirmed the GONPs cytotoxic effects on REF and HBL-100 cell lines. The outcome suggested caution in wide-spread applications of GONPs, which could have implications for occupational health also.

Effect of Graphene Oxide Nanoparticles on the Flexural Strength of all CeramicsAn In-vitro Study

Introduction: Desirable properties of monolithic ceramics like strength, stability at high temperatures, high stiffness has made it useful for biomedical, electronic, automotive, industrial, defence and space applications. The brittle nature and mechanical unreliability of monolithic ceramics limit their use. Aim: To evaluate, if there is an increase in flexural strength of all ceramics incorporated with graphene nanoparticles. Materials and Methods: This in-vitro study was conducted in the Department of Prosthodontics and Crown and Bridge, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India, from February 2021 to April 2021, where 20 specimens of all ceramic dimensions of 20×5×3 (20 mm in length, 5 mm in width, 3 mm in thickness) according to American Dental Association (ADA) specification number 69, 1991 for flexural strength were grouped into group A (Control) with no Graphene Oxide (GO), group B with GO added. A universal testing machine with a cross head speed of 0.5 mm/ min and a span length of 15 mm was used to load the specimen in the centre. To compare the flexural strength of the two groups, the Mann Whitney U-test was used. Normality was the data assessed using Shapiro-Wilk and Kolmogorov-Smirnov test. Results: The results show that there was a significant difference (p=0.001) in the mean flexural strength between the groups. Group B had the highest mean flexural strength of 562.61 MPa, while Group A had the lowest of 458.61 MPa. Conclusion: The results concluded that, all ceramics incorporated with graphene nanoparticles showed superior flexural strength.

Effect of graphene oxide nanoparticles on viability of BAP3 hybridoma cells

Graphene oxide (GO) is a promising material, which is likely to find applications in the fields of medicine and biotechnology. However, the current knowledge of its influence on human organism is limited. Even less information is available on the effects of GO on the cell lines widely used in biotechnology. The aim of this work is to describe the interaction between GO nanoparticles and BAP3 hybridoma cells which produce anti-human-PSG1 IgG, in vitro. We studied the effect of GO nanoparticles on cell viability and the intensity of internalization (adhesion) of nanoparticles by the cells. We used GO nanoparticles of different size, with surface being functionalized by linear or branched PEG (GO-PEG). The PEG coating level was 20% (by mass). The following nanoparticle concentrations were used: 5 g/mL and 25 g/mL. The BAP3 cells were cultured in a 48-well cell culture plates in serum-free DCCM-1 media in the presence of GO nanoparticles. The cells were cultured for 24 hours at 37 С and 5% СО2. Cell viability was assessed by a flow cytometer utilizing Zombie Aqua (ZA) staining. Internalization (adhesion) of nanoparticles was monitored using a flow cytometer by GO fluorescense in the samples (ex = 488 nm). Moreover, interactions between hybridoma cells and GO nanoparticles were visualized by EVOS M5000 visualization system, which included an inverted fluorescent microscope.
 We demonstrated that GO nanoparticles possess a cytotoxic effect when applied at high concentration (25 g/mL). The highest cytotoxic effect is caused by GO nanoparticles coated with linear PEG. The degree of nanoparticle internalization (adhesion) was shown to be significantly lower when the particles were present at lower (5 g/mL) concentration. Internalization (adhesion) of nanoparticles of smaller size was more abundant. Furthermore, these nanoparticles were shown to have a stronger cytotoxic effect compared to larger particles. In general, cytotoxicity of GO nanoparticles decreases with increasing size, which is especially evident if the fact that the mean effective diameter of the nanoparticles coated with branched PEG is considered larger than their linear PEG-coated counterparts. The data obtained allow us to draw a correlation between the cytotoxic effect of GO nanoparticles and the level of their internalization (adhesion) by the cells. In general, this work concerns some novel aspects of interaction between GO nanoparticles and hybridoma cells.

The cytotoxic effect of graphene oxide nanoparticles on bacterial cells

The results of research on the introduction of nanotechnology in various fields of scientific activities are presented. In medical and veterinary practice, nanoparticles of various forms of carbon are considered promising, because they have a wide arsenal of biomodulatory effects on the body, exhibiting little ecotoxic and organismotoxic effects. Their antibacterial effect is of great importance for the use in medicine. Microorganisms are one of the objects of study of the cytotoxic properties of new medicinal products. The cytotoxic effect of oxidized graphene nanoparticles on the main types of bacterial cells was evaluated by light and atomic force microscopy. Light microscopy allowed to establish that the effect of subinhibitory concentrations of nanoparticles of oxidized graphene, achieved by studying the colonies of microorganisms on the border of their growth inhibition, can lead to tinctorial transversion in Gram-positive microorganisms, in particular Staphylococcus aureus, while in Gram-negative E. coli such a phenomenon is not observed. Using the method of atomic force microscopy, it was found that toxic concentrations of oxidized graphene nanoparticles lead to morphological degradation, the degree of which depends on the exposure time of nanoparticles. Morphological degradation of cells in the main types of bacteria (cocci, bacilli), accompanied by a decrease in cell contours, was observed at 30 min exposure. When the exposure was increased from 30 to 90 min, complete morphological destruction of the bacterial cells and decay of the bacterial population composition were observed. The cytotoxic concentration of oxidized graphene nanoparticles is more than 75 µg·ml-1, as determined by the results of microscopy of test culture samples (Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538).

Effect of graphene oxide nanoparticles on blast load resistance of steel fiber reinforced concrete

Concrete structures may occasionally be subjected to both intentional or unintentional explosions which could cause casualties and damage to properties. Advance research on protective structures are important to enhance blast resistance of materials, and to protect life and properties. This study investigated the effect of graphene oxide nanoparticles (GO) on enhancing the blast resistance of fiber reinforced cement mortar (FRM). GO in solution was incorporated in steel fiber reinforced mortar at the rate of 0, 0.025, 0.050, 0.075, and 0.100 % by weight of cement. A series of experiments were carried out consisting of 2 stages: Stage 1) workability, setting time, compressive and flexural strength, and microstructure using SEM and XRD processes, and Stage 2) blasting loading test. The optimum GO dosage giving the highest compressive and flexural strengths from the 1st stage was determined and chosen to continue on the 2nd stage (blast loading test). The blasting tests were performed on panel specimens (500mmx1000mmx60mm) using TNT weighing ½ lb. (226.7 g) with three different standoff distances of 340, 400, and 460 mm. Results from Stage 1 on both flexural and compression tests indicated an optimum GO content of 0.025% by weight of cement. The workability was found to decrease with the increasing the GO content. The SEM images also revealed that the addition of GO nanoparticles reduced the porosity in the mortar matrix. For the blasting test, three damage patterns were observed: complete flexural failure, partial damage (flexural cracking), and no major damage, depending on the standoff distance and specimen type. The addition of GO can reduce the maximum and permanent deflections of the panel under blast loading. FRM panels with GO at 0.025% tested at the standoff distance of 460 mm showed the lowest level of damage.

Is airborne graphene oxide a possible hazard for the sexual reproduction of wind-pollinated plants?

Products containing graphene-related materials (GRMs) are becoming increasingly common, allowing GRM nanoparticles (NPs) to enter the environment during their life cycle. Thanks to their lightness and bidimensional geometry, GRM NPs can be easily dispersed in the air and travel very long distances. The flowers of wind-pollinated plants may be exposed to airborne GRMs, being apt to intercept pollen from the air and, inevitably, other airborne particles. Here, stigmas of four wind-pollinated plants (Corylus avellana, common hazel; Juglans regia, walnut; Quercus ilex, holm oak; Zea mays, maize) were exposed to airborne graphene oxide (GO) and GO purified from production residues (PGO) at a concentration of 3.7 ng m−3. Subsequently, the stigmas were pollinated and the adhesion of GOs and their effects on stigma integrity and pollen-stigma interaction were examined. The effect of GO NPs in presence of liquid water on the stigma of C. avellana was also investigated. GOs NPs were intercepted by all species, but their effect varied among them. GO reduced pollen adhesion in J. regia and Q. ilex, whereas pollen germination was unaffected in all four species. The presence of a film of water neither completely removed GO NPs from the stigma, nor it enhanced the toxic effect of GO acidity. PGO never affected pollen-stigma interaction, indicating that the phytotoxic substances used for the production of GO, still in traces in commercial GO, are the main cause of GO toxicity. These results reconfirm the need to verify GRMs effects also on key biological processes beside single model organisms.

Interaction of Human Dendritic Cells with Graphene Oxide Nanoparticles In Vitro.

We studied the effect of graphene oxide nanoparticles on the differentiation of human dendritic cells and uptake of nanoparticles by these cells in vitro. The objects of the study were mononuclear cells from healthy donors induced into the phenotype of dendritic cells by cytokines (IL-6 and GM-CSF). We used graphene oxide nanoparticles of different sizes functionalized with linear or branched PEG (P-GO or bP-GO) in concentrations of 5 and 25 μg/ml. It was found that graphene oxide nanoparticles did not affect the viability and percentage of dendritic cells in the culture. However, P-GO nanoparticles (25 μg/ml) suppressed the expression of CD83 on the surface of dendritic cells in cultures, thereby suppressing cell differentiation. Dendritic cells internalized P-GO nanoparticles, particles in high concentration were more actively engulfed, but the size of the particles and the type of PEG did not affect the intensity of this process. In general, P-GO nanoparticles in a concentration of 25 μg/ml can regulate differentiation of dendritic cells by suppressing their maturation.

Effect of Graphene Oxide Nanoparticles on Blast Load Resistance of Steel Fiber Reinforced Concrete

Effect of Graphene Oxide Nanoparticles on Blast Load Resistance of Steel Fiber Reinforced Concrete

Effect Of Graphene Oxide Nanoparticles on the Performance of Aerobic Granular Sludge Treatment System

Effect Of Graphene Oxide Nanoparticles on the Performance of Aerobic Granular Sludge Treatment System