Graphene Oxide Polyethylene Glycol Research Articles

Penicillin and Oxacillin Loaded on PEGylated-Graphene Oxide to Enhance the Activity of the Antibiotics against Methicillin-Resistant Staphylococcus aureus.

Infectious diseases are known as the second biggest cause of death worldwide, due to the development of antibiotic resistance. To overcome this problem, nanotechnology offers some promising approaches, such as drug delivery systems that can enhance drug efficiency. Herein, a Graphene Oxide-polyethylene glycol (GO-PEG) nano-platform was synthesized and penicillin and oxacillin, two antibiotics that are ineffective against Methicillin-resistant S. aureus (MRSA), were loaded on it to improve their effectiveness. The nanocomposites were characterized using FTIR, XRD, UV–Vis, FE-SEM/EDX, and Zeta potential analyses, followed by an evaluation of their antibacterial activity toward MRSA. Based on the results, drug loaded GO-PEG nanocomposites with loading efficiencies of 81% and 92% for penicillin and oxacillin, respectively, were successfully synthesized. They showed a controlled release within six days. The zeta potential of GO-PEG-oxacillin and penicillin was −13 mV and −11 mV, respectively. The composites showed much more activity against MRSA (80–85% inhibition) in comparison to GO-PEG (almost 0% inhibition) and pure antibiotics (40–45% inhibition). SEM images of MRSA treated with GO-PEG-antibiotics showed a deformation in the structure of bacterial cells, which led to the collapse of their intracellular components. These results demonstrate the effectiveness of utilizing the GO-based nanoplatforms in enhancing the antibacterial activity of the antibiotics.

Novel Graphene oxide-Polyethylene Glycol mono-4-nonylphenyl Ether adsorbent for solid phase extraction of Pb2+ in blood and water samples.

A novel and efficient Graphene Oxide-Polyethylene Glycol mono-4-nonylphenyl Ether (GO-PEGPE) nanocomposite was synthesized and used for solid phase extraction of trace levels of Pb2+ in different water and blood samples. The synthesized adsorbent was then characterized by the Fourier Transform-Infrared spectrophotometry (FT-IR), Field Emission-Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction analysis (XRD). To optimize the critical parameters including pH of samples solution, amounts of adsorbent and extraction time, the response surface methodology based on the central composite design (RSM-CCD) was used and based on the results, pH = 6.0, extraction time = 22min and amounts of adsorbent = 15mg were selected as the optimum conditions. The relative standard deviation based on seven replicate analysis of 2µg L-1 Pb2+ was 5.2% and the limit of detection was 0.023µg L-1 (n = 8). The results of adsorption isotherm investigation show that the adsorption of Pb2+ onto the GO-PEGPE nanocomposite obeyed by the Langmuir isotherm with the maximum adsorption capacity of 69.44mgg-1. Also, based on the Temkin and Dubinin-Radushkevich (DR) isotherms, the adsorption of Pb2+ onto the GO-PEGPE nanocomposite is a physisorption phenomenon and the consequences of the kinetic models illustrated that the adsorption of Pb2+ followed by the pseudo second order adsorption kinetic model. Finally, the proposed method was successfully applied for preconcentration of Pb2+ in different water and blood samples of turning industry workers.

Inhibition of cold‐welding and adhesive wear occurring on surface of the 6061 aluminum alloy by graphene oxide/polyethylene glycol composite water‐based lubricant

In this paper, graphene oxide/polyethylene glycol (GO/PEG) composite water‐based lubricant was prepared by an ultrasonic dispersion method, and characterized and analyzed by Fourier transform infrared (FT‐IR), Raman spectroscopy, X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The suspension performance of GO/PEG composite water‐based lubricant in water was verified by static sedimentation and centrifugation, and then, the prepared GO/PEG composite water‐based lubricant was added into 304 stainless steel and 6061 aluminum alloy, and the coefficient of friction (COF) curve, average COF value, average wear rate, corresponding photomicrographs of balls and disks after wear, and energy‐dispersive spectrometer (EDS) elemental analysis were used to illustrate the lubrication effect and lubrication mechanism. The results show that the GO/PEG composite water‐based lubricant possesses excellent suspension ability in water, and the average COF value and wear rate of GO/PEG composite water‐based lubricant are reduced by 78.8% and 88.8%, respectively, compared with water lubrication. The excellent lubrication effect of GO/PEG composite water‐based lubricant can effectively reduce the cold‐welding and adhesive wear phenomenon, mainly because GO/PEG composite water‐based lubricant first fills the uneven surface of friction mating to form a high‐quality lubricating film and then because of the special space structure of GO and the low shear between GO layers and the synergistic lubrication effect of GO/PEG.

Flexible graphene oxide/poly(ethylene glycol) composite films for lubrication application

For the rotating parts of low-speed heavy machinery, it is difficult to replace and add lubricants, so coating the mechanical surface is an effective method to reduce friction and wear. In this study, a smooth functional film with good mechanical strength was designed and prepared by combining graphene oxide (GO) with polyethylene glycol (PEG). This wachieved by grafting PEG onto the GO surface. The effects of lubrication for the cases of flexible lubricating film, no film, and single film were analysed. The lubrication characteristics of GO–PEG flexible composite film under water lubrication, are discussed in detail. The results show that the mixture of PEG and GO can significantly improve the thermal stability, film forming properties and mechanical properties of GO–PEG composites. The membrane has a good friction limit performance. Compared with the uncoated surface, the friction coefficient is reduced by 74% and the wear rate is reduced by 70%.

Effects of GO-PEG on the performance and structure of PVC ultrafiltration membranes

In this work, neat and nanocomposite polyvinyl chloride (PVC) membranes with various contents of graphene oxide-poly ethylene glycol (GO-PEG) nanosheets were fabricated via non-solvent phase separation (NIPS) method. The results of field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses approved the successful synthesis of GO-PEG nanosheets. Fabricated PVC/GO-PEG membranes were characterized by atomic force microscopy (AFM), water content, FESEM, contact angle, porosity, pure water flux (PWF), abrasion resistance and tensile strength tests. FESEM images illustrated the increased porosity of membranes after embedding of GO-PEG. The results showed that by addition of nanosheets, abrasion resistance of membranes enhanced as a reason of good mechanical properties of GO. Moreover, PWF was improved from 50 L/m2 h in neat PVC to around 211 L/m2 h in 0.15 wt.% PVC/GO-PEG membrane. Finally, MBR filtration test was utilized for 360 min to evaluate membranesʼ performance. In this case, Reversible Fouling Ratio (RFR) increased (from 9% in neat PVC membrane to 33% in PVC/GO-PEG 0.15 wt.% membrane) and Irreversible Fouling Ratio (IFR) decreased (from 51% in neat PVC to 37% in PVC/GO-PEG 0.15 wt.% membrane) by addition of GO-PEG nanosheets. The improved antifouling properties of PVC/GO-PEG membranes can be attributed not only to the hydrophilicity effect of GO-PEG nanosheets which prevents the foulants from attaching to membranes surface but also to the increased flux of PVC/GO-PEG membranes.

Tribological properties of graphene oxide and polyethylene glycol composites under dry friction and oil lubrication conditions

AbstractIn the low speed and heavy load of large machinery rotation or sliding parts, the application of copper base ink plate is very extensive. In this study, the graphene oxide‐polyethylene glycol (GO‐PEG) thin films were prepared on the surface of steel plates by gradient heating, and we simulated the friction and wear state of the solid material when it was brought to the metal surface. And the Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray energy spectrum analysis, Raman spectroscopy (Raman), and thermogravimetric analysis were used to characterize the structure and properties. The tribological results show that the GO‐PEG composite film prepared by gradient temperature rise method has good lubrication effect. The addition of GO greatly enhances the mechanical properties of the composite films. Compared with the single GO film, the friction coefficient is reduced by 50% and the wear rate is reduced by 85%. The unique characteristics of PEG solved the accumulation phenomenon caused by the strong van der Waals force between GO, then the PEG adhered on GO surfaces caused good lubrication effect. At the same time, the composite film has a broad application prospect in the working environment with little oil and no oil.

Bioactivity of PEGylated Graphene Oxide Nanoparticles Combined with Near-Infrared Laser Irradiation Studied in Colorectal Carcinoma Cells.

Central focus in modern anticancer nanosystems is given to certain types of nanomaterials such as graphene oxide (GO). Its functionalization with polyethylene glycol (PEG) demonstrates high delivery efficiency and controllable release of proteins, bioimaging agents, chemotherapeutics and anticancer drugs. GO–PEG has a good biological safety profile, exhibits high NIR absorbance and capacity in photothermal treatment. To investigate the bioactivity of PEGylated GO NPs in combination with NIR irradiation on colorectal cancer cells we conducted experiments that aim to reveal the molecular mechanisms of action of this nanocarrier, combined with near-infrared light (NIR) on the high invasive Colon26 and the low invasive HT29 colon cancer cell lines. During reaching cancer cells the phototoxicity of GO–PEG is modulated by NIR laser irradiation. We observed that PEGylation of GO nanoparticles has well-pronounced biocompatibility toward colorectal carcinoma cells, besides their different malignant potential and treatment times. This biocompatibility is potentiated when GO–PEG treatment is combined with NIR irradiation, especially for cells cultured and treated for 24 h. The tested bioactivity of GO–PEG in combination with NIR irradiation induced little to no damages in DNA and did not influence the mitochondrial activity. Our findings demonstrate the potential of GO–PEG-based photoactivity as a nanosystem for colorectal cancer treatment.

Graphene Oxide Loaded with Protocatechuic Acid and Chlorogenic Acid Dual Drug Nanodelivery System for Human Hepatocellular Carcinoma Therapeutic Application.

Hepatocellular carcinoma or hepatoma is a primary malignant neoplasm that responsible for 75–90% of all liver cancer in humans. Nanotechnology introduced the dual drug nanodelivery method as one of the initiatives in nanomedicine for cancer therapy. Graphene oxide (GO) loaded with protocatechuic acid (PCA) and chlorogenic acid (CA) have shown some anticancer activities in both passive and active targeting. The physicochemical characterizations for nanocomposites were conducted. Cell cytotoxicity assay and lactate dehydrogenase were conducted to estimate cell cytotoxicity and the severity of cell damage. Next, nanocomposite intracellular drug uptake was analyzed using a transmission electron microscope. The accumulation and localization of fluorescent-labelled nanocomposite in the human hepatocellular carcinoma (HepG2) cells were analyzed using a fluorescent microscope. Subsequently, Annexin V- fluorescein isothiocyanate (FITC)/propidium iodide analysis showed that nanocomposites induced late apoptosis in HepG2 cells. Cell cycle arrest was ascertained at the G2/M phase. There was the depolarization of mitochondrial membrane potential and an upregulation of reactive oxygen species when HepG2 cells were induced by nanocomposites. In conclusion, HepG2 cells treated with a graphene oxide–polyethylene glycol (GOP)–PCA/CA–FA dual drug nanocomposite exhibited significant anticancer activities with less toxicity compared to pristine protocatechuic acid, chlorogenic acid and GOP–PCA/CA nanocomposite, may be due to the utilization of a folic acid-targeting nanodrug delivery system.

Polyethylene Glycol Functionalized Graphene Oxide Nanoparticles Loaded with Nigella sativa Extract: A Smart Antibacterial Therapeutic Drug Delivery System.

Flaky graphene oxide (GO) nanoparticles (NPs) were synthesized using Hummer’s method and then capped with polyethylene glycol (PEG) by an esterification reaction, then loaded with Nigella sativa (N. sativa) seed extract. Aiming to investigate their potential use as a smart drug delivery system against Staphylococcus aureus and Escherichia coli, the spectral and structural characteristics of GO-PEG NPs were comprehensively analyzed by XRD, AFM, TEM, FTIR, and UV- Vis. XRD patterns revealed that GO-PEG had different crystalline structures and defects, as well as a higher interlayer spacing. AFM results showed GONPs with the main grain size of 24.41 nm, while GONPs–PEG revealed graphene oxide aggregation with the main grain size of 287.04 nm after loading N. sativa seed extract, which was verified by TEM examination. A strong OH bond appeared in FTIR spectra. Furthermore, UV- Vis absorbance peaks at (275, 284, 324, and 327) nm seemed to be correlated with GONPs, GO–PEG, N. sativa seed extract, and GO –PEG- N. sativa extract. The drug delivery system was observed to destroy the bacteria by permeating the bacterial nucleic acid and cytoplasmic membrane, resulting in the loss of cell wall integrity, nucleic acid damage, and increased cell-wall permeability.

Graphene oxide-polyethylene glycol incorporated PVDF nanocomposite ultrafiltration membrane with enhanced hydrophilicity, permeability, and antifouling performance

The novel highly hydrophilic composite additive, graphene oxide-polyethylene glycol (GO-PEG, further abbreviated as P-GO), was synthesized from GO and PEG by the esterification reaction. Then, P-GO was blended into a polyvinylidene fluoride (PVDF) casting solution as an additive, and the effects of P-GO on the performance of the PVDF ultrafiltration (UF) membrane were researched. When amount of added P-GO was 0.5 wt%, the flux of the resultant modified membrane (denoted as P/0.5P-GO) reached as high as 93 L m−2·h−1, that is twice than that of the pure PVDF membrane (45 L m−2·h−1). Furthermore, water contact angle results confirmed significantly improved hydrophilicity of the P/0.5P-GO membrane. Results of antifouling tests revealed that the P/0.5P-GO membrane showed the lowest total resistance and irreversible resistance among all the membranes prepared in this study, and after physical cleaning, its flux recovery ratio was the highest—78%. These results demonstrated improved antifouling performance of the P/0.5P-GO membrane. Therefore, it can be concluded that P-GO as an additive material for the PVDF membrane has satisfactory performance in improving the membrane hydrophilicity, permeability, and antifouling performance in practical applications.

Graphene Oxide/Polyethylene Glycol-Stick for Thin Film Microextraction of β-Blockers from Human Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry.

A wooden stick coated with a novel graphene-based nanocomposite (Graphene oxide/polyethylene glycol (GO/PEG)) is introduced and investigated for its efficacy in solid phase microextraction techniques. The GO/PEG-stick was prepared and subsequently applied for the extraction of β-blockers, acebutolol, and metoprolol in human oral fluid samples, which were subsequently detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). Experimental parameters affecting the extraction protocol including sample pH, extraction time, desorption time, appropriate desorption solvent, and salt addition were optimized. Method validation for the detection from oral fluid samples was performed following FDA (Food and Drug Administration) guidelines on bioanalytical method validation. Calibration curves ranging from 5.0 to 2000 nmol L−1 for acebutolol and 25.0 to 2000 nmol L−1 for metoprolol were used. The values for the coefficient of determination (R2) were found to be 0.998 and 0.996 (n = 3) for acebutolol and metoprolol, respectively. The recovery of analytes during extraction was 80.0% for acebutolol and 62.0% for metoprolol, respectively. The limit of detections (LODs) were 1.25, 8.00 nmol L−1 for acebutolol and metoprolol and the lower limit of quantifications (LLOQ) were 5.00 nmol L−1 for acebutolol and 25.0 nmol L−1 for metoprolol. Validation experiments conducted with quality control (QC) samples demonstrated method accuracy between 80.0% to 97.0% for acebutolol and from 95.0% to 109.0% for metoprolol. The inter-day precision for QC samples ranged from 3.6% to 12.9% for acebutolol and 9.5% to 11.3% for metoprolol. Additionally, the GO/PEG-stick was demonstrated to be reusable, with the same stick observed to be viable for more than 10 extractions from oral fluid samples.

Dual Drugs Anticancer Nanoformulation using Graphene Oxide-PEG as Nanocarrier for Protocatechuic Acid and Chlorogenic Acid.

The chemotherapy of cancer has been complicated by poor bioavailability, adverse side effects, high dose requirement, drug resistance and low therapeutic indices. Cancer cells have different ways to inhibit the chemotherapeutic drugs, use of dual/multiple anticancer agents may be achieve better therapeutic effects in particular for drug resistant tumors. Designing a biocompatible delivery system, dual or multiple drugs could addressing these chemotherapy drawbacks and it is the focus of many current biomedical research. In the present study, graphene oxide-polyethylene glycol (GOPEG) nanocarrier is designed and loaded with two anticancer drugs; Protocatechuic acid (PCA) and Chlorogenic acid (CA). The designed anticancer nanocomposite was further coated with folic acid to target the cancer cells, as their surface membranes are overexpressed with folate receptors. The particle size distribution of the designed nanocomposite was found to be narrow, 9-40nm. The release profiles of the loaded drugs; PCA and CA was conducted in human body simulated PBS solutions of pH7.4 (blood pH) and pH4.8 (intracellular lysosomal pH). Anticancer properties were evaluated against cancerous cells i.e. liver cancer, HEPG2 and human colon cancer, HT-29 cells. The cytocompatbility was assessed on normal 3T3 fibroblasts cells. The size of the final designed anticancer nanocomposite formulation, GOPEG-PCACA-FA was found to be distributed at 9-40 nm with a median of 8 nm. The in vitro release of the drugs PCA and CA was found to be of sustained manner which took more than 100h for the release. Furthermore, the designed formulation was biocompatible with normal 3T3 cells and showed strong anticancer activity against liver and colon cancer cells.

Graphene Oxide⁻PEG⁻Protocatechuic Acid Nanocomposite Formulation with Improved Anticancer Properties.

The treatment of cancer through chemotherapy is limited by its toxicity to healthy tissues and organs, and its inability to target the cancer site. In this study, we have designed an anticancer nanocomposite delivery system for protocatechuic acid (PCA) using graphene oxide–polyethylene glycol as the nanocarrier, and coated with folic acid (GO–PEG–PCA–FA) for targeting the cancer cells. The designed anticancer delivery system was found to show much better anticancer activity than the free drug PCA against liver cancer HEP-G2 cells and human colon cancer HT-29 cells; at same time, it was found to be less toxic to normal fibroblast 3T3 cells. The folate-coated anticancer delivery system was found to show better activity then the free drug and the uncoated anticancer delivery system. The in vitro release of the PCA was found to be sustained in human physiological pHs, i.e., blood pH 7.4 and intracellular lysosomal pH 4.8. These in vitro findings are highly encouraging for further in vivo evaluation studies.

Antitumor Effect of GO-PEG-DOX Complex on EMT-6 Mouse Breast Cancer Cells.

Doxorubicin (DOX) can be used to treat malignant tumors, but with multiple adverse effects. Graphene oxide-polyethylene glycol (GO-PEG) is a novel nanoscale carrier material and can elevate solubility and biocompatibility of drugs. This study prepared a GO-PEG-DOX complex, whose toxicity and antitumor effects were evaluated on mouse EMT-6 breast cancer cells. GO-PEG-DOX complex was prepared for calculating the drug carrier rate of DOX on GO-PEG by MV approach. EMT-6 cells were treated with 40 μg/mL GO-PEG, 1 μg/mL DOX, or 40 μg/mL +1 μg/mL GO-PEG-DOX for 72 h of incubation. Cells without treatment were considered the control group. Cell survival rate and apoptotic rate were tested at different time points. GO-PEG and GO-PEG-DOX complex were successfully prepared with satisfactory solubility. After 72 h of incubation, EMT-6 cells after GO-PEG-DOX treatment had significantly higher survival rate than GO-PEG group (p < 0.05). All three treatment groups had significantly elevated apoptotic rates than control group (p < 0.05). GO-PEG-DOX group had much more apoptosis (p < 0.05 compared with DOX group). Moreover, with elongated treatment time, all groups showed decreased survival rate (p < 0.05). GO-PEG did not reduce the cytotoxicity of DOX on EMT-6 cells. GO-PEG-DOX complex can increase the water solubility and targeting sensitivity of DOX, with facilitating effects on DOX-induced tumor cell apoptosis.

Synthesis and self-assembly of a PEGylated-graphene aerogel

In the frame of this work, we present, for the first time, the synthesis and self-assembly of an aerogel built by graphene oxide-polyethylene glycol. The synthetic route involves at first the coupling of GO with an amino-terminated polyethylene glycol sample by carbodiimide in aqueous environment, and the subsequent conversion of the hydrogel achieved into an aerogel via freeze-drying. The 3D PEGylated graphene-based aerogel, characterized by spectroscopic, morphological, structural and mechanical analyses, displays an ultralight and highly porous (99.7%) network and possesses high mechanical properties together with a good biocompatibility.

Facile synthesis of PEG based shape-stabilized phase change materials and their photo-thermal energy conversion

Polyethylene glycol (PEG) based shape-stabilized phase change materials (PCMs) were successfully synthesized by a facile and effective physical blending method with the assistance of microwave. Graphene oxide (GO), as a supporting material, was added in PEG matrix to improve the thermal properties of PCMs and keep their stabilized shape during the phase change process. With the assistance of microwave, the interlayer spacing of GO sheets was expanded and the entire blending process was time saving. A small content (about 4 wt%) of GO could make the composite absorb energy efficiently without leakage during their phase change because of the hydrogen bonding and capillary force between the GO layers and PEG molecular chain. The DSC results showed that the composites had a heat storage capacity of 174.5 J/g, which was 95.6% of the phase change enthalpy of pure PEG. The photo-thermal energy conversion of the composites was explored.

Infrared Photothermal Therapy with Water Soluble Reduced Graphene Oxide: Shape, Size and Reduction Degree Effects

In this work, we investigate the effects of lateral size and reduction level of polyethylene glycol (PEG)-modified graphene oxide (GO) nanosheets on the photothermal properties. PEG-modified GO (GO–PEG) and reduced graphene oxide (rGO–PEG) matrices were synthesized through amide bond formation between the carboxyl groups of carboxylated GO and rGO and the amine groups of a PEG linker. We found that the reaction temperature has an important influence on the morphology and size of the pegylated nanostructures. While rGO–PEG formed at 80°C is of nanometer size, the GO–PEG, prepared at room temperature, has needle-like shape with micrometric dimensions. The rGO–PEG matrix was found to be highly soluble under physiological conditions with no aggregation observed even after 6 months of storage. The cytotoxicity of both matrices as well as their photothermal properties to ablate cervical HeLa cancer cells and MDA-MB-231 human breast carcinoma cells were studied. There was no sign of acute toxicity of rGO–PEG for HeLa and MDA-MB-31 cancer cells over a wide concentration range. A complete destruction of the tumor cells could be achieved with a laser power of 6 W cm-2 and a concentration of 60 μg mL-1 of rGO–PEG.

Hydrous-ferric oxide nanorods grown on PEGylated graphene oxide with superior capacity for selective adsorption of albumin

A ferrate functionalized graphene-based composite is prepared by growth of hydrous ferric oxide (FeOOH) on the polyethylene glycol (PEG) modified graphene oxide (GO) sheets. The obtained GO–PEG–FeOOH composite is characterized by ATR-FTIR, TEM, AFM, XPS and ICP-MS. The PEGylation significantly changes the surface property of the bare graphene oxide, which not only generates a nano-bio-interface for protein interaction but also reduces the non-specific adsorption of proteins. The PEGylation and growth of FeOOH nanorods on GO sheets obviously enhanced the selectivity toward the adsorption of albumin through strong hydrogen bonding interaction, exhibiting an ultra-high adsorption capacity of 1377.4mgg−1 for bovine serum albumin (BSA). It is obviously higher than those achieved by any hitherto reported graphene based materials and other carbon nanomaterials. Albumin retained by the composite could be effectively recovered with a 4.0mM B–R buffer through the affinity of boronic acid toward protein, giving rise to a recovery of 70%. Circular dichroism (CD) spectra indicate no conformational change for BSA during the process of adsorption/desorption. The practical applicability of the GO nanocomposite is further demonstrated by the selective adsorption/isolation of albumin from complex biological samples matrixes, e.g., human whole blood.