Nanotoxicity of Graphene and Graphene Oxide

Graphene Oxide Quantum Dot-Based Functional Nanomaterials for Effective Antimicrobial Applications

Conventional β-lactam antibiotics are resisted by bacteria at an increasing rate, prompting studies into the development of alternate antibiotic agents. In this personal account, we summarize recent progress in the design and engineering of graphene oxide quantum dot-based nanomaterials as potent antimicrobial agents. Specifically, we examine the impacts of chemical reduction on the antimicrobial activity of graphene oxide quantum dots, and enhancement of the bactericidal performance by the formation of nanocomposites with metal oxide nanoparticles, within the context of photodynamic generation of reactive oxygen species. A perspective is also included where the promises and challenges are highlighted in the development of high-performance antimicrobial agents based on graphene derivatives.

Ciprofloxacin and Graphene Oxide Combination-New Face of a Known Drug

Drug modification with nanomaterials is a new trend in pharmaceutical studies and shows promising results, especially considering carbon-based solutions. Graphene and its derivatives have attracted much research interest for their potential applications in biomedical areas as drug modifiers. The following work is a comprehensive study regarding the toxicity of ciprofloxacin (CIP) modified by graphene oxide (GO). The influence on the morphology, viability, cell death pathway and proliferation of T24 and 786-0 cells was studied. The results show that ciprofloxacin modified with graphene oxide (CGO) shows the highest increase in cytotoxic potential, especially in the case of T24 cells. We discovered a clear connection between CIP modification with GO and the increase in its apoptotic potential. Our results show that drug modification with carbon-based nanomaterials might be a promising strategy to improve the qualities of existing drugs. Nevertheless, it is important to remember that cytotoxicity effects are highly dependent on dose and nanomaterial size. It is necessary to conduct further research to determine the optimal dose of GO for drug modification.

Mechanistic Insights into the Cytotoxicity of Graphene Oxide Derivatives in Mammalian Cells

Graphene oxide derivatives (GODs) have superb physical/chemical properties with promise for applications in biomedicine. Shape, size, and chemistry of the GODs are identified as the key parameters that impact any biological system. In this work, the GODs with a wide range of shapes (sheets, helical/longitudinal ribbons, caps, dots), sizes (10 nm to 20 μm), and chemistry (partially to fully oxidized) are synthesized, and their cytotoxicity in normal cells (NIH3T3) and colon cancer cells (HCT116) are evaluated. The mechanisms by which the GODs induce cytotoxicity are comprehensively investigated, and the toxic effects of the GODs on the NIH3T3 and the HCT116 cells are compared. While the GODs show no toxicity under the size of 50 nm, they impose moderate toxic effects at the sizes of 100 nm to 20 μm (max viability >57%). For the GODs with the similar size (100-200 nm), the helical ribbon-like structure is found to be much less toxic than the longitudinal ribbon structure (max viability 83% vs 18%) and the tubular structure (0% viability for the oxidized carbon nanotubes). It is also evident that the level of oxidation of the GOD is inversely related to the toxicity. Although the extent of GOD-induced cytotoxicity (reduction of cell viability) to the two cell lines is similar, their toxicity mechanisms are interestingly found to be substantially different. In the HCT116 cancer cells, cell membrane leakage leads to DNA damage followed by cell death, whereas in the NIH3T3 normal cells, increases in oxidative stress and physical interference between the GODs and the cells are identified as the main toxicity sources.

Codelivery of HIF-1α siRNA and Dinaciclib by Carboxylated Graphene Oxide-Trimethyl Chitosan-Hyaluronate Nanoparticles Significantly Suppresses Cancer Cell Progression

PURPOSE

Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules.

METHODS

In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth.

RESULTS

The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells.

CONCLUSIONS

These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFβ, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).

Graphene oxide inhibits cell migration and invasion by destroying actin cytoskeleton in cervical cancer cells

OBJECTIVE

To investigate the antitumor effects of Graphene oxide (GO) on tumor invasion and metastasis in human cervical cancer Hela cells.

RESULTS

GO significantly inhibited cell viability and the number of clones, promoted cell apoptosis, as well as suppressed cell migration and invasion, and destroyed the structure of actin cytoskeleton of Hela cells in a dose-dependent manner in. Moreover, the expression of metastasis-related proteins, including MMP2 and Cdc42, were significantly suppressed by the treatment of GO. And the expression of MMP3 was remarkably increased by Smad inhibitor and the protein levels of MMP3 and ICAM were elevated by the JNK inhibitor in GO-treated Hela cells.

CONCLUSION

GO exhibited inhibitory effects on cell migration and invasion possibly by destroying actin cytoskeleton in Hela cells, which is a potential component of the Smad and JNK signalling pathways.

METHODS

GO was prepared and chracterized by UV visible light absorption spectroscopy and atomic force microscopy. Hela cells were treated with Go at different dose levels. Then, in vitro cytotoxicity of GO was evaluated by the MTT assay, colony-forming assay and cell apoptosis assay. The inhibitory effects of GO on tumor cell migration and invasion as well as actin cytoskeleton were explored using Hela cells.

Toxic impacts and industrial potential of graphene

Advancement in the field of nanotechnology has increased the synthesis and exploitation of graphene-like nanomaterials. Graphene is a two-dimensional planar and hexagonal array of carbon atoms. Due to its flexible nature graphene and its derivatives have several significant prospects extending from electronics to life sciences and drug delivery systems. In this review, we enlist some of the toxic effects of graphene family nanomaterials (GFNs) in various aspects of biosystems viz., in vitro, in vivo, microbial, molecular and environmental. We also appreciate their extensive and promising applications though with some underlying challenges. This review also draws attention toward current and future prospect of global graphene market for wide-range commercialization.

Graphene oxide as a new anthropogenic stress factor - multigenerational study at the molecular, cellular, individual and population level of Acheta domesticus

Although interest in transgenerational phenomena is constantly growing, little is known about the long-term toxicity of nanoparticles. In this study we investigate the multigenerational effects of graphene oxide (GO) which was given to Acheta domesticus in low doses (0.2, 2 and 20 μg·g^-1 of food) for three subsequent generations. We assessed the influence of GO nanoparticles in many contexts, basing on parameters which represented different levels of biological organization: activity of antioxidant enzymes, level of apoptosis, DNA damage, histological analysis, hatching abilities, body mass and body length of insects, as well as their survival rate. The results have shown that exposing insects to nanoparticles over an extended period of time causes surprising intergenerational effects, based on significant differences in the life cycle and reproductive processes, which are not always dose-dependent. The second generation of insects appeared as the most unstable among the parameters that were studied, and did not match trends and patterns in the first and third generation categories. An increase of DNA damage was observed, but only in the third generation. This reduction of genome stability can be perceived as an essential element of adaptation, leading to an increase of genotype variants, which then undergo selection.

Cytotoxicity and Immune Dysfunction of Dendritic Cells Caused by Graphene Oxide

Graphene, known as “black gold”, has important applications in various fields. In previous studies, it has been proved that graphene oxide (GO) which is a derivative of graphene has low toxicity. However, the immunotoxicity of GO has not been fully elucidated. In this work, we used DC2.4 cell line to investigate the in vitro immunotoxicity of two types of GO, mono-layer GO (mono-GO) and multi-layer GO (multi- GO). We found that mono-GO had less effect on cell viability than multi-GO, but both mono-GO and multi-GO significantly induced the generation of ROS in DC2.4 cells. Interestingly, mono-GO caused DC2.4 cells to aggregate, thus changed the cell morphology significantly. However, no similar influence occurred for multi-GO. In addition, the results showed that these two GOs obviously enhance the release of TNF-α by DC2.4 cells with and without LPS stimulation. GO did not affect the level of IL-6 released from DC2.4 cells, but multi-GO promoted the release of IL-6 while mono-GO inhibited the production of IL-6 when cells were in response to LPS stimulation. Whole-transcriptome sequencing analysis found some immune-related differentially expressed genes including H2-DMb1, Ncbp3, Oas2, Men1, Fas, Cd320, Cd244, and Tinagl1 which are engaged in the immune system process. These results suggested that both mono-GO and multi-GO are immunotoxic to DC2.4 cells, which provides important basis for subsequent biological and clinical medical applications.

Theranostic Nanoplatforms of Thiolated Reduced Graphene Oxide Nanosheets and Gold Nanoparticles

In this study, graphene oxide (GO) and reduced-thiolated GO (rGOSH) were used as 2D substrate to fabricate nanocomposites with nanoparticles of gold nanospheres (AuNS) or nanorods (AuNR), via in situ reduction of the metal salt precursor and seed-mediated growth processes. The plasmonic sensing capability of the gold-decorated nanosheets were scrutinized by UV-visible (UV-VIS) spectroscopy. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analyses (TGA), and atomic force microscopy (AFM) were performed in order to prove the actual reduction that occurred concomitantly with the thiolation of GO, the increase in the hydrophobic character as well as the size, and preferential gathering of the gold nanoparticles onto the nanosheet substrates, respectively. Moreover, the theoretical electronic and infrared absorption (UV-VIS and IR) spectra were calculated within a time-dependent approach of density functional theory (DFT). Eventually, in vitro cellular experiments on human neuroblastoma cells (SH-SY5Y line) were carried out in order to evaluate the nanotoxicity of the nanocomposites by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction (MTT) colorimetric assay. Results pointed out the promising potential of these hybrids as plasmonic theranostic platforms with different hydrophilic or hydrophobic features as well as cytotoxic effects against cancer cells.

Protein Corona and Immune Responses of Borophene: A Comparison of Nanosheet-Plasma Interface with Graphene and Phosphorene

Borophene has emerged as a type of two-dimensional monoelemental nanomaterials with excellent drug loading capacity and photothermal properties. Here, we demonstrated the adsorption of plasma proteins onto borophene nanosheets (B NSs) and the promoted immune responses of macrophage by the B NS-corona complex. We discovered that plasma proteins changed the surface identities of B NSs. Using proteomics analysis, 46.5% of the proteins bound to B NSs (94 plasma proteins) were immune-relevant proteins. Uptake of B NSs by phagolysosomes was observed, and the plasma corona promoted the uptake. In comparison with graphene and phosphorene, we found that 32 plasma proteins appeared on all of the three nanosheets. The proportion of immune-relevant proteins in graphene-corona and phosphorene-corona was 41.3% and 75.6%, respectively. The components of the adsorbed immune-relevant proteins show diversity, which influence the immune responses of these nanosheets. Phosphorene-corona showed the most remarkable immunoregulatory behavior in these nanosheets. For the first time, we compared the highly complex protein corona at the nanosheet-plasma interface of three key 2D monoelemental nanosheets. Our study helps to understand the interaction between borophene and biological systems and provides a theoretical basis for the development and application of borophene in the biomedical field.

Nanotoxicity of ZrS3 Probed in a Bioluminescence Test on E. coli Bacteria: The Effect of Evolving H2S

Materials from a large family of transition metal trichalcogenides (TMTCs) attract considerable attention because of their potential applications in electronics, optoelectronics and energy storage, but information on their toxicity is lacking. In this study, we investigated the toxicity of ZrS₃, a prominent TMTC material, toward photoluminescent E. coli bacteria in a bioluminescence test. We found that freshly prepared ZrS₃ suspensions in physiological saline solution with concentrations as high as 1 g/L did not exhibit any toxic effects on the bacteria. However, ZrS₃ suspensions that were stored for 24 h prior to the bioluminescence tests were very toxic to the bacteria and inhibited their emission, even at concentrations down to 0.001 g/L. We explain these observations by the aqueous hydrolysis of ZrS₃, which resulted in the formation of ZrO_x on the surface of ZrS₃ particles and the release of toxic H₂S. The formation of ZrO_x was confirmed by the XPS analysis, while the characteristic H₂S smell was noticeable for the 24 h suspensions. This study demonstrates that while ZrS₃ appears to be intrinsically nontoxic to photoluminescent E. coli bacteria, it may exhibit high toxicity in aqueous media. The results of this study can likely be extended to other transition metal chalcogenides, as their toxicity in aqueous solutions may also increase over time due to hydrolysis and the formation of H₂S. The results of this study also demonstrate that since many systems involving nanomaterials are unstable and evolve over time in various ways, their toxicity may evolve as well, which should be considered for relevant toxicity tests.

Comprehensive Review on Graphene Oxide for Use in Drug Delivery System

Motivated by the accomplishment of carbon nanotubes (CNTs), graphene and graphene oxide (GO) has been widely investigated in the previous studies as an innovative medication nanocarrier for the loading of a variety of therapeutics as well as anti-cancer medications, poor dissolvable medications, antibiotics, antibodies, peptides, DNA, RNA and genes. Graphene provides the ultra-high drug-loading efficiency due to the wide surface area. Graphene and graphene oxide have been widely investigated for biomedical applications due to their exceptional qualities: twodimensional planar structure, wide surface area, chemical and mechanical constancy, sublime conductivity and excellent biocompatibility. Due to these unique qualities, GO applications provide advanced drug transports frameworks and transports of a broad range of therapeutics. In this review, we discussed the latest advances and improvements in the uses of graphene and GO for drug transport and nanomedicine. Initially, we have described what is graphene and graphene oxide. After that, we discussed the qualities of GO as a drug carrier, utilization of GO in drug transport applications, targeted drug transport, transport of anticancer medications, chemical control medicine releasee, co-transport of different medications, comparison of GO with CNTs, nano-graphene for drug transport and at last, we have discussed the graphene toxicity. Finally, we draw a conclusion of current expansion and the potential outlook for the future.

Beyond graphene oxide acidity: Novel insights into graphene related materials effects on the sexual reproduction of seed plants

Graphene related materials (GRMs) are currently being used in products and devices of everyday life and this strongly increases the possibility of their ultimate release into the environment as waste items. GRMs have several effects on plants, and graphene oxide (GO) in particular, can affect pollen germination and tube growth due to its acidic properties. Despite the socio-economic importance of sexual reproduction in seed plants, the effect of GRMs on this process is still largely unknown. Here, Corylus avellana L. (common Hazel) pollen was germinated in-vitro with and without 1-100 μg mL^-1 few-layer graphene (FLG), GO and reduced GO (rGO) to identify GRMs effects alternative to the acidification damage caused by GO. At 100 μg mL^-1 both FLG and GO decreased pollen germination, however only GO negatively affected pollen tube growth. Furthermore, GO adsorbed about 10 % of the initial Ca²⁺ from germination media accounting for a further decrease in germination of 13 % at the pH created by GO. In addition, both FLG and GO altered the normal tip-focused reactive oxygen species (ROS) distribution along the pollen tube. The results provided here help to understand GRMs effect on the sexual reproduction of seed plants and to address future in-vivo studies.

Carbon family nanomaterials — new applications and technologies

Research on carbon-based nanomaterials (CBNMs) and their development is one of the major scientific disciplines of the last century. This is mainly because of their unique properties which can lead to improvements in industrial technology or new medical applications. Therefore, it is necessary to examine their properties such as shape, size, chemical composition, density, toxicity, etc. This article focuses on the general characteristics of nanomaterials (NMs) and their behavior when entering the environment (water and soil). In addition, it presents individual members of the graphene family including porous ecological carbon (biochar). The article mainly deals with the new potential technologies of CBNMs considering their possible toxic and genotoxic effects. This review also highlights the latest developments in the application of self-propelled micromotors for green chemistry applications. Finally, it points to the potential biomedical applications of CBNMs.

Efficient As(III) Removal by Novel MoS2-Impregnated Fe-Oxide-Biochar Composites: Characterization and Mechanisms

Sorbents that efficiently eliminate toxic metal(loid)s from industrial wastes are required for the protection of the environment and human health. Therefore, we demonstrated efficient As(III) removal by novel, eco-friendly, hydrothermally prepared MoS₂-impregnated FeO _x @BC800 (MSF@BC800). The properties and adsorption mechanism of the material were investigated by X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. The synergistic effects of FeO _x and MoS₂ on MSF@BC800 considerably enhanced As(III)-removal efficiency to ≥99.73% and facilitated superior As(III) affinity in aqueous solutions (K _d ≥ 10⁵ mL g^-1) compared to those of FeO _x @BC800 and MS@BC800, which showed 37.07 and 17.86% As(III)-removal efficiencies and K _d = 589 and 217 mL g^-1, respectively, for an initial As(III) concentration of ∼10 mg L^-1. The maximum Langmuir As(III) sorption capacity of MSF@BC800 was 28.4 mg g^-1. Oxidation of As(III) to As(V) occurred on the MSF@BC800 composite surfaces. Adsorption results agreed with those obtained from the Freundlich and pseudo-second-order models, suggesting multilayer coverage and chemisorption, respectively. Additionally, MSF@BC800 characteristics were examined under different reaction conditions, with temperature, pH, ionic strength, and humic acid concentration being varied. The results indicated that MSF@BC800 has considerable potential as an eco-friendly environmental remediation and As(III)-decontamination material.

Evolving Strategies for Producing Multiscale Graphene-Enhanced Fiber-Reinforced Polymer Composites for Smart Structural Applications

Graphene has become an important research focus in many current fields of science including composite manufacturing. Developmental work in the field of graphene-enhanced composites has revealed several functional and structural characteristics that promise great benefits for their use in a broad range of applications. There has been much interest in the production of multiscale high-performance, lightweight, yet robust, multifunctional graphene-enhanced fiber-reinforced polymer (gFRP) composites. Although there are many reports that document performance enhancement in materials through the inclusion of graphene nanomaterials into a matrix, or its integration onto the reinforcing fiber component, only a few graphene-based products have actually made the transition to the marketplace. The primary focus of this work concerns the structural gFRPs and discussion on the corresponding manufacturing methodologies for the effective incorporation of graphene into these systems. Another important aspect of this work is to present recent results and highlight the excellent functional and structural properties of the resulting gFRP materials with a view to their future applications. Development of clear standards for the assessment of graphene material properties, improvement of existing materials and scalable manufacturing technologies, and specific regulations concerning human health and environmental safety are key factors to accelerate the successful commercialization of gFRPs.

Interaction and Reactivity of Cisplatin Physisorbed on Graphene Oxide Nano-Prototypes

The physical adsorption of cisplatin (CP) on graphene oxide (GO) and reduced graphene oxide (rGO) is investigated at the DFT level of theory by exploiting suitable molecular prototypes representing the most probable adsorbing regions of GO and rGO nano-structures. The results show that the CP binding energy is enhanced with respect to that for the interaction with pristine graphene. This is due to the preferential adsorption of the drug in correspondence of the epoxy and hydroxy groups located on GO basal plane: an energy decomposition analysis of the corresponding binding energy reveals that the most attractive contribution comes from the electrostatic attraction between the -NH3 ends of CP and the oxygen groups on (r)GO, which can be associated with hydrogen bonding effects. Moreover, it is found that the reactivity of the physically adsorbed CP is practically unaltered being the free energy variation of the first hydrolysis reaction almost matching that of its free (unadsorbed drug) counterpart. The reported results suggest that the CP physical adsorption on GO and rGO carriers is overall feasible being an exergonic process in aqueous solution. The CP adsorption could facilitate its solubility and transport in water solutions, exploiting the high hydrophilicity of the peripheral carboxylic groups located on the edge of the GO and rGO nano-structures. Moreover, the the higher affinity of CP with respect to the oxidized sites suggests a possible dependence of drug loading and release on pH conditions, which would highly facilitate its specific delivery.

Systemic and Local Biocompatibility Assessment of Graphene Composite Dental Materials in Experimental Mandibular Bone Defect

The main objective of this research is to demonstrate the biocompatibility of two experimental graphene dental materials by in vitro and in vivo tests for applications in dentistry. The novel graphene dental materials, including one restorative composite and one dental cement, were subjected to cytotoxicity and implantation tests by using a rat model of a non-critical mandibular defect. In vitro cytotoxicity induced by materials on human dental follicle stem cells (restorative composite) and dysplastic oral keratinocytes (dental cement) was investigated at 37 °C for 24 h. After in vivo implantation, at 7 weeks, bone samples were harvested and subjected to histological investigations. The plasma biochemistry, oxidative stress, and sub-chronic organ toxicity analysis were also performed. The resulting cytotoxicity tests confirm that the materials had no toxic effects against dental cells after 24 h. Following graphene dental materials implantation, the animals did not present any symptoms of acute toxicity or local inflammation. No alterations were detected in relative organ weights and in correlation with hepatic and renal histological findings. The materials' lack of systemic organ toxicity was confirmed. The outcomes of our study provided further evidence on the graphene dental materials' ability for bone regeneration and biocompatibility.

Delivery of Salvianolic Acid B for Efficient Osteogenesis and Angiogenesis from Silk Fibroin Combined with Graphene Oxide

The efficiency of drugs often hinges on drug carriers. To effectively transport therapeutic plant molecules, drug delivery carriers should be able to carry large doses of therapeutic drugs, enable their sustained release, and maintain their biological activity. Here, graphene oxide (GO) is demonstrated to be a valid carrier for delivering therapeutic plant molecules. Salvianolic acid B (SB), which contains a large number of hydroxyl groups, bound to the carboxyl groups of GO by self-assembly. Silk fibroin (SF) substrates were combined with functionalized GO through the freeze-drying method. SF/GO scaffolds could be loaded with large doses of SB, maintain the biological activity of SB while continuously releasing SB, and significantly promote the osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). SF/GO/SB also dramatically enhanced endothelial cell (EA-hy9.26) migration and tubulogenesis in vitro. Eight weeks after implantation of SF/GO/SB scaffolds in a rat cranial defect model, the defect area showed more new bone and angiogenesis than that following SF and SF/GO scaffold implantation. Therefore, GO is an effective sustained-release carrier for therapeutic plant molecules, such as SB, which can repair bone defects by promoting osteogenic differentiation and angiogenesis.

In vivo toxicity evaluation of boron nitride nanosheets in Bombyx mori silkworm model

Boron nitride nanosheets (BN NSs), a novel material with a structure similar to graphene, have attracted much attention due to their extraordinary properties. A deep in vivo study of the toxicity of BN NSs is indispensable, which can help to understand their potential risk and provide useful information for their safe application. However, so far as we know, the systematic in vivo toxicity evaluation of BN NSs hasn't been reported. In this study, silkworm (Bombyx mori) was used as a model to investigate the toxicity of BN NSs, by continuously feeding silkworm larvae with BN NSs at various mass concentrations (1%, 2%, 3%, 4%). The toxicity was evaluated from the levels of animal entirety (mortality, silkworm growth, cocoons and silk properties), tissues (pathological examination) and genes (transcriptomic profiling). The results show that the exposure to BN NSs causes no obvious adverse effects on the growth, silk properties or tissues of silkworm, but the expressions of genes in midgut concerned with some specific functions and pathways are significantly changed, indicating that BN NSs may have potential danger to lead to dysfunction. This study has performed in vivo toxicity evaluation of BN NSs and provided useful safety information for the application of BN NSs.

Size-Dependent Effects of Suspended Graphene Oxide Nanoparticles on the Cellular Fate of Mouse Neural Stem Cells

PURPOSE

In this study, we aim to explore the effects of graphene oxide (GO), a derivative of graphene, nanoparticles of four different sizes on the cellular fate of mouse neural stem cells (mNSCs).

METHODS

GO NPs were characterized with transmission electron microscopy (TEM), scanning electron micrography (SEM), atomic force microscopy (AFM) and Raman Spectra analysis. The cytotoxic effects of the GO NPs of different sizes on the mNSCs were determined using CCK-8 assay, Annexin V-APC/ 7-AAD staining and EdU staining assays. We investigated the biological and the mechanisms of GO NPs on cells using immunofluorescence analysis and quantitative real-time PCR (qPCR).

RESULTS

The average hydrodynamic sizes of the GO NPs were 417 nm, 663 nm, 1047 nm, and 4651 nm, with a thickness of approximately 22.5 nm, 17.7 nm, 22.4 nm, and 13.4 nm, respectively. GO NPs of all sizes showed low cytotoxicity at a concentration of 20 μg/mL on the mNSCs. Immunostaining demonstrated that treatment with GO NPs, especially the 663 nm ones, enhanced the self-renewal ability of mNSCs in the absence of EGF and bFGF. Under differentiation medium conditions that are free of mitogenic factors, all the GO NPs, particularly the 4651 nm ones, increased the expression level of Tuj1 and GFAP. With regards to the migration ability, we found that 417 nm GO-NP-treated mNSCs migrated over a longer distance than the control group obviously. In addition, higher expression of Rap1, Vinculin and Paxillin was observed in the GO NP-treated groups compared to the control group. mRNA-Sequence analysis and Western blotting results suggested that the 4651 nm GO NPs triggered positive neuronal differentiation through phosphorylation of ERK1/2 by the downregulating of TRPC2.

CONCLUSION

GO NPs play an important role in the applications of inducing self-renewal and differentiation of mNSC, and are promising in the future for further studies.

Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance

Catheter-related infections are a common worldwide health problem, highlighting the need for antimicrobial catheters. Here, antibacterial potential of graphene nanoplatelets (GNP) incorporated in the commonly used polymer for catheter manufacture-polyurethane (PU)-is investigated. Two strategies are explored: melt-blending, producing a composite, and dip coating, where a composite layer is deposited on top of PU. GNP with different lateral sizes and oxidation degrees-GNP-M5, GNP-M15, GNP-M5ox, GNP-M15ox-are applied in both strategies, and the antimicrobial potential towards Staphylococcus epidermidis of GNP dispersions and GNP-containing PU evaluated. As dispersions, oxidized and smaller GNP powders (GNP-M5ox) inhibit 74% bacteria growth at 128 µg/mL. As surfaces, GNP exposure strongly impacts their antimicrobial profile: GNP absence at the surface of composites yields no significant effects on bacteria, while by varying GNP: PU ratio and GNP concentration, coatings enhance GNP exposure, depicting an antimicrobial profile. Oxidized GNP-containing coatings induce higher antibacterial effect than non-oxidized forms, particularly with smaller GNPox, where a homogeneous layer of fused platelets is formed on PU, leading to 70% reduction in bacterial adhesion and 70% bacterial death. This pioneering work unravels how to turn a polymer clinically used to produce catheters into an antimicrobial surface, crucial to reducing risk of infection associated with catheterization.

Vancomycin modified copper sulfide nanoparticles for photokilling of vancomycin-resistant enterococci bacteria

Due to the overuse of antibiotics, vancomycin resistant enterococci (VRE) has caused serious infections and become more and more difficult to deal with. Herein, we reported a facile one-pot strategy to synthesize copper sulfide nanoparticles using vancomycin (Van) as reductant and capping agent (CuS@Van). The as-prepared CuS@Van nanocomposites presented excellent uniformity in particle size and strong near infrared (NIR) absorbance. Fourier Transform infrared spectroscopy (FTIR) and Energy dispersive spectrometry (EDS) analysis confirmed the successful modification of Van molecules on the surface of CuS@Van nanoparticles. Bacterial TEM images verified the specific binding affinity between CuS@Van and VRE pathogen. CuS@Van also exhibited effective photokilling capability based on a combination of photothermal therapy (PTT) and photodynamic therapy (PDT). Fluorescent bacterial viability staining and bacterial growth curves monitoring were performed to explore the photokilling ablation of CuS@Van against VRE pathogens. The in vitro results indicated that CuS@Van nanocomposites had no antibacterial activity in the dark but displayed satisfying bactericidal effect against VRE pathogens upon the NIR irradiation. Mouse infection assays were also implemented to evaluate in vivo antibacterial photokilling effectiveness. CuS@Van with NIR irradiation showed the highest antibacterial capability and fastest infection regression compared with the control groups. Considering the low cost, easy preparation, good biocompatibility and excellent photokilling capability, CuS@Van nanocomposites will shed bright light on the photokilling ablation of vancomycin-resistant pathogenic bacteria.

Directional extraction and penetration of phosphorene nanosheets to cell membranes

Recently, phosphorene, a novel two-dimensional nanomaterial with a puckered surface morphology, was shown to exhibit cytotoxicity, but its underlying molecular mechanisms remain unknown. Herein, using large scale molecular dynamics simulations, we show that phosphorene nanosheets can penetrate into and extract large amounts of phospholipids from the cell membranes due to the strong dispersion interaction between phosphorene and lipid molecules, which would reduce cell viability. The extracted phospholipid molecules are aligned along the wrinkle direction of the phosphorene nanosheet because of its unique puckered structure. Our results also reveal that small phosphorene nanosheets penetrate into the cell membrane in a specific direction which is determined by the size and surface topography of phosphorene and the thickness of the membrane. These findings might shed light on understanding phosphorene's cytotoxicity and would be helpful for the future potential biomedical applications of phosphorene, such as biosensors and antibacterial agents.

Graphene Oxide Promotes Cancer Metastasis through Associating with Plasma Membrane To Promote TGF-β Signaling-Dependent Epithelial-Mesenchymal Transition

Nanomedicines are being developed to treat diverse diseases; however, inadvertent or unintended health effects have to be considered, especially for those targeting cancers. For cancers, occurrence of metastasis hints an advanced phase of cancer progression, and nanomedicines per se should be evaluated for their effects on existing metastatic tumors and triggering metastases. Graphene-based 2D nanomaterials, such as graphene oxide (GO), due to its unique characteristics, have been extensively studied for biomedical applications including cancer therapy. However, the potential effect of GO on metastasis has not been determined yet. Herein, we found that low-dose GO could induce significant morphological and structural changes of the cellular membrane within cancer cells, suggesting an epithelial-mesenchymal transition (EMT), with enhanced invasion/migration and the alterations of representative EMT indicators in GO-treated cells. These changes resulted in enhanced lung metastasis of cancer cells in various metastasis models. The mechanistic investigations unveiled that GO increased the protein levels of the TGF-β receptor, leading to a constitutively activated TGF-β-Smad2/3 signaling pathway that drives the EMT. Collectively, our findings enhance the understanding of the unintended side and detrimental effects of GO nanosheets in increasing the progression of metastatic tumors. Thus, the likelihood of pro-EMT effects upon low-dose GO exposure should be considered when developing GO nanomedicines.

Progress in supercapacitors: roles of two dimensional nanotubular materials

Overcoming the global energy crisis due to vast economic expansion with the advent of human reliance on energy-consuming labor-saving devices necessitates the demand for next-generation technologies in the form of cleaner energy storage devices. The technology accelerates with the pace of developing energy storage devices to meet the requirements wherever an unanticipated burst of power is indeed needed in a very short time. Supercapacitors are predicted to be future power vehicles because they promise faster charging times and do not rely on rare elements such as lithium. At the same time, they are key nanoscale device elements for high-frequency noise filtering with the capability of storing and releasing energy by electrostatic interactions between the ions in the electrolyte and the charge accumulated at the active electrode during the charge/discharge process. There have been several developments to increase the functionality of electrodes or finding a new electrolyte for higher energy density, but this field is still open to witness the developments in reliable materials-based energy technologies. Nanoscale materials have emerged as promising candidates for the electrode choice, especially in 2D sheet and folded tubular network forms. Due to their unique hierarchical architecture, excellent electrical and mechanical properties, and high specific surface area, nanotubular networks have been widely investigated as efficient electrode materials in supercapacitors, while maintaining their inherent characteristics of high power and long cycling life. In this review, we briefly present the evolution, classification, functionality, and application of supercapacitors from the viewpoint of nanostructured materials to apprehend the mechanism and construction of advanced supercapacitors for next-generation storage devices.

Estimation of genomic instability and mutation induction by graphene oxide nanoparticles in mice liver and brain tissues

The rapidly growing interest in using graphene-based nanoparticles in a wide range of applications increases human exposure and risk. However, very few studies have investigated the genotoxicity and mutagenicity of the widely used graphene oxide (GO) nanoparticles in vivo. Consequently, this study estimated the possible genotoxicity and mutagenicity of GO nanoparticles as well as possible oxidative stress induction in the mice liver and brain tissues. Nano-GO particles administration at the dose levels of 10, 20, or 40 mg/kg for one or five consecutive days significantly increased the DNA breakages in a dose-dependent manner that disrupts the genetic material and causes genomic instability. GO nanoparticles also induced mutations in the p53 (exons 6&7) and presenilin (exon 5) genes as well as increasing the expression of p53 protein. Positive p53 reaction in the liver (hepatic parenchyma) and brain (cerebrum, cerebellum, and hippocampus) sections showed significant increase of p53 immunostaining. Additionally, induction of oxidative stress was proven by the significant dose-dependent increases in the malondialdehyde level and reductions in both the level of reduced glutathione and activity of glutathione peroxidase observed in GO nanoparticles administered groups. Acute and subacute oral administration of GO nanoparticles induced genomic instability and mutagenicity by induction of oxidative stress in the mice liver and brain tissues.

In vivo immunological response of exposure to PEGylated graphene oxide via intraperitoneal injection

2D PEGylated graphene oxide showed stealth-but-immune-activating capacity on macrophages, along with specific intraperitoneal immunological response in vivo.

Graphene oxide/alginate composites as novel bioinks for three-dimensional mesenchymal stem cell printing and bone regeneration applications

Three-dimensional (3D) cell printing is a versatile technique enabling the creation of 3D constructs containing hydrogel and cells in the desired shape or pattern. Bioinks exhibiting appropriate mechanical properties and biological activities to support cell growth and/or differentiation toward a specific lineage play critical roles in 3D cell printing and tissue engineering applications. Herein, we explored alginate/graphene oxide (GO) composites as bioinks for their potential to improve printability, structural stability, and osteogenic activities for osteogenic tissue engineering applications. The addition of GO (0.05-1.0 mg mL^-1) to 3% alginate significantly enhanced the printing performances of the alginate bioink. In addition, mesenchymal stem cells (MSCs) printed with alginate/GO showed good proliferation and higher survival in an oxidative stress environment. The 3D scaffolds printed with MSCs and alginate/GO demonstrated significantly enhanced osteogenic differentiation compared with those printed with MSCs and alginate. Overall, a bioink of 3% alginate and 0.5 mg mL^-1 GO showed the most balanced characteristics in terms of printability, structural stability, and osteogenic induction of the printed MSCs. Alginate/GO composite bioinks will be useful for bioprinting research for various tissue engineering applications.

Interaction Analysis of Commercial Graphene Oxide Nanoparticles with Unicellular Systems and Biomolecules

The ability of commercial monolayer graphene oxide (GO) and graphene oxide nanocolloids (GOC) to interact with different unicellular systems and biomolecules was studied by analyzing the response of human alveolar carcinoma epithelial cells, the yeast Saccharomyces cerevisiae and the bacteria Vibrio fischeri to the presence of different nanoparticle concentrations, and by studying the binding affinity of different microbial enzymes, like the α-l-rhamnosidase enzyme RhaB1 from the bacteria Lactobacillus plantarum and the AbG β-d-glucosidase from Agrobacterium sp. (strain ATCC 21400). An analysis of cytotoxicity on human epithelial cell line A549, S. cerevisiae (colony forming units, ROS induction, genotoxicity) and V. fischeri (luminescence inhibition) cells determined the potential of both nanoparticle types to damage the selected unicellular systems. Also, the protein binding affinity of the graphene derivatives at different oxidation levels was analyzed. The reported results highlight the variability that can exist in terms of toxicological potential and binding affinity depending on the target organism or protein and the selected nanomaterial.

Graphene oxide mitigates endocrine disruption effects of bisphenol A on zebrafish at an early development stage

Development from embryos to larvae is an important life stage and impairments in this stage could affect the development and growth of fish. In this study, the endocrine disruption and developmental toxicities of bisphenol A (BPA) (50 and 500 μg/L) in the presence of graphene oxide (GO) (0.1 and 1 mg/L) were investigated on zebrafish embryos from 6 to 168 h post fertilization (hpf). BPA alone displayed significant endocrine disruption effects (increase in the estradiol (E2)/testosterone (T) ratio, vitellogenin (VTG) and estrogen receptor α (erα) in larvae), promoted embryos hatching and caused larvae malformation. There was a significant correlation between VTG level and erα expression, suggesting that erα played a vital role in VTG synthesis. However, all these adverse effects were alleviated distinctly in the presence of GO. GO formed a coating layer on the embryos chorion membrane, depressing absorption of BPA by the embryos. As a consequence, bioaccumulation of BPA in zebrafish co-exposed to GO and BPA decreased by >50% compared with the BPA single exposure group. Adsorption of BPA on GO might also make a partial contribution to the reduced accumulation of BPA in the larvae. The results demonstrated that GO could relieve the estrogenic and developmental effects of BPA on zebrafish in the early development stage.

Interaction of Graphene Nanoparticles and Lipid Membranes Displaying Different Liquid Orderings: A Molecular Dynamics Study

Understanding the effects of graphene-based nanomaterials on lipid membranes is fundamental to determine their environmental impact and the efficiency of their biomedical use. By means of molecular dynamics simulations of simple model lipid bilayers, we analyze in detail the different interaction modes. We have studied bilayers consisting of lipid species (including cholesterol) which display different internal liquid orderings. Nanometric graphene layers can be transiently adsorbed onto the lipid membrane and/or inserted in its hydrophobic region. Once inserted, graphene nanometric flakes display a diffusive dynamics in the membrane plane, they adopt diverse orientations depending on their size and oxidation degree, and they show a particular aversion to be placed close to cholesterol molecules in the membrane. Addition of graphene to phase-segregated ternary membranes is also investigated in the context of the lipid raft model for the lipid organization of biological membranes. Our simulation results show that graphene layers can be inserted indistinctly in the ordered and disordered regions. Once inserted, nanometric flakes migrate to disordered and cholesterol-poor lipid phases.

Macrophage inflammatory and metabolic responses to graphene-based nanomaterials differing in size and functionalization

The preparation of graphene-based nanomaterials (GBNs) with appropriate stability and biocompatibility is crucial for their use in biomedical applications. In this work, three GBNs differing in size and/or functionalization have been synthetized and characterized, and their in vitro biological effects were compared. Pegylated graphene oxide (GO-PEG, 200-500 nm) and flavin mononucleotide-stabilized pristine graphene with two different sizes (PG-FMN, 200-400 nm and 100-200 nm) were administered to macrophages, chosen as cellular model due to their key role in the processing of foreign materials and the regulation of inflammatory responses. The results showed that cellular uptake of GBNs was mainly influenced by their lateral size, while the inflammatory potential depended also on the type of functionalization. PG-FMN nanomaterials (both sizes) triggered significantly higher nitric oxide (NO) release, together with some intracellular metabolic changes, similar to those induced by the prototypical inflammatory stimulus LPS. NMR metabolomics revealed that macrophages incubated with smaller PG-FMN displayed increased levels of succinate, itaconate, phosphocholine and phosphocreatine, together with decreased creatine content. The latter two variations were also detected in cells incubated with larger PG-FMN nanosheets. On the other hand, GO-PEG induced a decrease in the inflammatory metabolite succinate and a few other changes distinct from those seen in LPS-stimulated macrophages. Assessment of TNF-α secretion and macrophage surface markers (CD80 and CD206) further corroborated the low inflammatory potential of GO-PEG. Overall, these findings revealed distinct phenotypic and metabolic responses of macrophages to different GBNs, which inform on their immunomodulatory activity and may contribute to guide their therapeutic applications.

Reactivity of graphene oxide with reactive oxygen species (hydroxyl radical, singlet oxygen, and superoxide anion)

Increases in the production and applications of graphene oxide (GO), coupled with reports of its toxic effects, are raising concerns about its health and ecological risks. To better understand GO's fate and transport in aquatic environments, we investigated its reactivity with three major reactive oxygen species (ROS): HO˙, ¹O₂, and O₂˙^-. Second-order degradation rate constants were calculated on the loss of dissolved organic carbon (DOC) and steady-state concentration of individual ROS species. Absolute second-order rate constants were determined by competition kinetics to be 6.24 × 10⁴, 8.65 × 10², and 0.108 mg-C^-1 L s^-1 for HO˙, ¹O₂, and O₂˙^-, respectively. Photoreduced GO products had a similar reactivity to HO˙ as GO, with rate constants comparable to polycyclic aromatic compounds, but about two times higher than dissolved organic matter on a per carbon basis. Reaction with HO˙ resulted in decomposition of GO, with loss of color and formation of photoluminescent products. In contrast, reaction with ¹O₂ showed no effect on DOC, UV-vis spectra or particle size, while reaction with O₂˙- slightly reduced GO. These results demonstrate that interactions with ROS will affect GO's persistence in water and should be considered in exposure assessment or environmental application of GO.

Transferrin-targeting redox hyperbranched poly(amido amine)-functionalized graphene oxide for sensitized chemotherapy combined with gene therapy to nasopharyngeal carcinoma

A drug and gene co-delivery system with chemotherapeutic sensibilization was prepared and used for nasopharyngeal carcinoma therapy. For this purpose, the graphene oxide (GO) was conjugated with the redox hyperbranched poly(amido amine) (HPAA) and then the targeting molecule, transferrin (Tf), was also conjugated. The obtained Tf-HPAA-GO could co-deliver docetaxel (DOC) and MMP-9 shRNA plasmid (pMMP-9) effectively and showed the targeting effect to HNE-1 cells. The co-delivery system showed the effective drug and gene delivery ability with high cytotoxicity and gene transfection efficiency. Besides that, Tf-HPAA-GO/DOC also showed the chemotherapeutic sensibilization effect, the formulation containing HPAA segments showed much higher cytotoxicity than free DOC. Benefiting from the sensibilization effect and DOC/pMMP-9 co-delivery strategy, this Tf-HPAA-GO/DOC/pMMP-9 co-delivery system exhibited the significantly improved therapeutic efficacy to HNE-1 tumor in a combined manner which was confirmed by in vitro and in vivo assays. This strategy provided an easily delivery system combining the drug/gene co-delivery, chemotherapeutic sensibilization, and targeting into one single platform, which showed a promising application in cancer therapy.

Covalent Epitope Decoration of Carbon Electrodes using Solid Phase Peptide Synthesis

Long-term, minimally perturbative brain electrophysiology requires electrodes to seamlessly integrate into surrounding tissue. In this work, we demonstrate electrodes composed of covalently functionalized graphite, decorated with various functional affinity and epitope tags, and use them to detect changes in electrical potential on the surfaces of illuminated quantum dots and near fluorescing molecules. Affinity and epitope tagging of carbon was achieved using direct attachment of biotin and solid phase peptide synthesis (SPPS) of histidine (His)- and human influenza hemagglutinin (HA)-tags. Surface modification was confirmed with Auger, Energy-Dispersive X-ray (EDX), Raman, and fluorescence spectroscopy. Photoresponse was detected with compatible binding protein-surface tag combinations, confirming desired tag and electrode functionality. These results provide a path to organic, biofunctionalized, fully molecularly-defined electrodes for neuronal applications, and to a wide range of other secondary reactions and modifications of carbon; potential uses include affinity chromatography, DNA sequencing technologies, biomolecular sensors, and surfaces and scaffolds for targeted interfaces with biological tissues.

Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

Natural methylxanthines, caffeine, theophylline and theobromine, are widespread biologically active alkaloids in human nutrition, found mainly in beverages (coffee, tea, cocoa, energy drinks, etc.). Their detection is thus of extreme importance, and many studies are devoted to this topic. During the last decade, graphene oxide (GO) and reduced graphene oxide (RGO) gained popularity as constituents of sensors (chemical, electrochemical and biosensors) for methylxanthines. The main advantages of GO and RGO with respect to graphene are the easiness and cheapness of synthesis, the notable higher solubility in polar solvents (water, among others), and the higher reactivity towards these targets (mainly due to - interactions); one of the main disadvantages is the lower electrical conductivity, especially when using them in electrochemical sensors. Nonetheless, their use in sensors is becoming more and more common, with the obtainment of very good results in terms of selectivity and sensitivity (up to 5.4 × 10-10 mol L-1 and 1.8 × 10-9 mol L-1 for caffeine and theophylline, respectively). Moreover, the ability of GO to protect DNA and RNA from enzymatic digestion renders it one of the best candidates for biosensors based on these nucleic acids. This is an up-to-date review of the use of GO and RGO in sensors.

Well-defined Graphene Oxide as a Potential Component in Lung Cancer Therapy

BACKGROUND

Graphene oxide (GO) has unique physical and chemical properties that can be used in anticancer therapy - especially as a drug carrier. Graphene oxide, due to the presence of several hybrid layers of carbon atoms (sp2), has a large surface for highly efficient drug loading. In addition, GO with a large number of carboxyl, hydroxyl and epoxy groups on its surface, can charge various drug molecules through covalent bonds, hydrophobic interactions, hydrogen bonds and electrostatic interactions.

OBJECTIVE

The aim of our work was to evaluate the possibility of future use of graphene oxide as an anticancer drug carrier.

METHODS

In this paper, we present GO synthesis and characterization, as well as a study of its biological properties. The cytotoxic effect of well-defined graphene oxide was tested on both carcinoma and non-malignant cells isolated from the same organ, which is not often presented in the literature.

RESULTS

The performed research confirmed that GO in high concentrations (> 300 µgmL-1) selectively decreased the viability of cancer cell line. Additionally, we showed that the GO flakes have a high affinity to cancer cell nucleus which influences their metabolism (inhibition of cancer cell proliferation). Moreover, we have proved that GO in high concentrations can cause cell membrane damage and generate reactive oxygen species on a low level mainly in cancer cells.

CONCLUSION

The proposed GO could be useful in anticancer therapy. A high concentration of GO selectively causes the death of tumor cells, whereas GO with low concentration could be a potential material for anticancer drug loading.

Widely distributed nanocolloids in water regulate the fate and risk of graphene oxide

The environmental behaviors and risks associated with graphene oxide (GO, a popular 2D nanomaterial) have attracted considerable attention. GO released to aquatic systems will most likely interact with ubiquitous nanocolloids (Nc) in surface water. However, the effects of Nc on the fate and risk of GO remain largely unknown in water. Herein, the binding of Nc onto GO was investigated via electron microscopy, electron paramagnetic resonance, 2D correlation spectroscopy and biolayer interferometry. The results revealed that electron charge transfers, hydrophilic effects and π-π stacking contributed to a strong affinity (K_D = 5.6 nM) and high adsorption capacity (159.8 mg/g) of Nc onto the GO surface. Moreover, GO nanosheets transformed to a scroll morphology or multiple GO particles bridging by Nc, which remarkably reduced the aggregation and sedimentation rates after binding with Nc. Interestingly, co-exposure with Nc greatly alleviated the toxicity (e.g., tail malformation, yolk sac edema and oxidative stress) of GO to zebrafish embryos. Morphological and structural alterations of GO after binding to Nc contributed to the mechanisms for the antagonistic effects on the zebrafish embryos toxicity. The present work provides insights into the environmental fate and risk of GO by ubiquitous Nc in natural water.

Graphene Modified Multifunctional Personal Protective Clothing

Personal protective clothing is intended to protect the wearer from various hazards (mechanical, biological, chemical, thermal, radiological, etc.) and inhospitable environmental conditions that may cause harm or even death. There are various types of personal protective clothing, manufactured with different materials based on hazards and end user requirements. Conventional protective clothing has impediments such as high weight, bulky nature, lack of mobility, heat stress, low heat dissipation, high physical stress, diminishing dexterity, diminishing scope of vision, lack of breathability, and reduced protection against pathogens and hazards. By virtue of the superlative properties of graphene, fabrics modified with this material can be an effective means to overcome these limitations and to improve properties such as mechanical strength, antibacterial activity, flame resistance, conductivity, and UV resistance. The limitations of conventional personal protective equipment are discussed, followed by necessary measures which might be taken to improve personal protective equipment (PPE), the unique properties of graphene, methods of graphene incorporation in fabrics, and the current research status and potential of graphene-modified performance textiles relevant to PPE.