“…In case of bCel the deconvulated Br 3d reveals peak at 70.01 eV corresponding to covalently bonded bromine while peak at 67.29 eV (Fig. 3d) represents for physically adsorbed bromine which is similar to bGO as discussed above 38 .Figure 2XPS survey spectrum ( a ) GO, and ( b ) Cel.Figure 3( a ) C1s peak of GO, ( b ) high resolution 3d peak of bGO, ( c ) C1s peak of Cel and, ( d ) high resolution 3d peak of bCel, respectively.Figure 4A c onvoluted spectrum of ( a ) N1s peak of qGO and ( b ) N1s peak of qCel.…”
Anion exchange membrane fuel cells (AEMFCs) have captivated vast interest due to non-platinum group metal catalysts and fuel flexibility. One of the major shortcomings of AEMFCs, however, is the lack of a stable and high anion conducting membrane. This study introduces a new strategy for fabrication of high conducting anion exchange membrane (AEM) using a hybrid nanocomposite of graphene oxide (GO), cellulose, and poly(phenylene oxide) (PPO), which are functionalized with 1,4-diazabicyclo[2.2.2]octane. The compositional ratio of GO/cellulose/PPO was optimized with respect to ionic conductivity, water uptake, swelling ratio, and mechanical properties. The membrane at GO/cellulose/PPO weight ratio of 1/1/100 displayed an impressive hydroxyl conductivity of ∼114 mS/cm at 25 °C and ∼215 mS/cm at 80 °C, which is considerably higher than the highest value reported. Further, the hybrid composite membranes were mechanically stable even when operating at high temperature (80 °C). The result indicates that the introduction of quaternized GO and cellulose into a polymer matrix is a promising approach for designing high performance AEMs.
“…In case of bCel the deconvulated Br 3d reveals peak at 70.01 eV corresponding to covalently bonded bromine while peak at 67.29 eV (Fig. 3d) represents for physically adsorbed bromine which is similar to bGO as discussed above 38 .Figure 2XPS survey spectrum ( a ) GO, and ( b ) Cel.Figure 3( a ) C1s peak of GO, ( b ) high resolution 3d peak of bGO, ( c ) C1s peak of Cel and, ( d ) high resolution 3d peak of bCel, respectively.Figure 4A c onvoluted spectrum of ( a ) N1s peak of qGO and ( b ) N1s peak of qCel.…”
Anion exchange membrane fuel cells (AEMFCs) have captivated vast interest due to non-platinum group metal catalysts and fuel flexibility. One of the major shortcomings of AEMFCs, however, is the lack of a stable and high anion conducting membrane. This study introduces a new strategy for fabrication of high conducting anion exchange membrane (AEM) using a hybrid nanocomposite of graphene oxide (GO), cellulose, and poly(phenylene oxide) (PPO), which are functionalized with 1,4-diazabicyclo[2.2.2]octane. The compositional ratio of GO/cellulose/PPO was optimized with respect to ionic conductivity, water uptake, swelling ratio, and mechanical properties. The membrane at GO/cellulose/PPO weight ratio of 1/1/100 displayed an impressive hydroxyl conductivity of ∼114 mS/cm at 25 °C and ∼215 mS/cm at 80 °C, which is considerably higher than the highest value reported. Further, the hybrid composite membranes were mechanically stable even when operating at high temperature (80 °C). The result indicates that the introduction of quaternized GO and cellulose into a polymer matrix is a promising approach for designing high performance AEMs.
“…The large surface area of GO flakes makes it amenable to modifications with various functional groups, enabling targeted delivery through different modes of administration such as oral and injectable rounts . GOs that are functionalized with chitosan, poly(acrylic acid) (PAA), and thiols have demonstrated the capacity to improve bioavailability and mucoadhesive properties of GO nanoparticles. − In particular, thiolated GOs exhibited improved mucoadhesive properties and prolonged residence time in mucosal tissues, such as the gastrointestinal tract, offering the potential for targeted delivery of drugs and nucleotides to specific areas affected by IBD . PAA-modified GOs were shown to be pH sensitive and have proven valuable for intracellular protein delivery via oral administration in intestinal tissue .…”
Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with a complex and multifactorial etiology, making it challenging to treat. While recent advances in immunomodulatory biologics, such as antitumor necrosis factor-α (TNFα) antibodies, have shown moderate success, systemic administration of antibody therapeutics may lead to several adverse effects, including the risk of autoimmune disorders due to systemic cytokine depletion. Transient RNA interference using exogenous short interfering RNA (siRNA) to regulate target gene expression at the transcript level offers an alternative to systemic immunomodulation. However, siRNAs are susceptible to premature degradation and have poor cellular uptake. Graphene oxide (GO) nanoparticles have been shown to be effective nanocarriers for biologics due to their reduced cytotoxicity and enhanced bioavailability. In this study, we evaluate the therapeutic efficacy of GO mediated TNF-α_siRNA using in vitro models of chronic inflammation generated by treating murine small intestines (enteroids) and large intestines (colonoids) with inflammatory agents IL-1β, TNF-α, and LPS. The organotypic mouse enteroids and colonoids developed an inflammatory phenotype similar to that of IBD, characterized by impaired epithelial homeostasis and an increased production of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. We assessed siRNA delivery to these inflamed organoids using three different GO formulations. Out of the three, small-sized GO with polymer and dendrimer modifications (smGO) demonstrated the highest transfection efficiency, which led to the downregulation of inflammatory cytokines, indicating an attenuation of the inflammatory phenotype. Moreover, the transfection efficiency and inflammation-ameliorating effects could be further enhanced by increasing the TNF-α_siRNA/smGO ratio from 1:1 to 3:1. Overall, the results of this study demonstrate that ex vivo organoids with disease-specific phenotypes are invaluable models for assessing the therapeutic potential of nanocarrier-mediated drug and biologic delivery systems.
“…A requirement for this quality is a flexible used to load the drug with the help of an electric charge [ 24 ]. Graphene oxide (GO) provides an “off-start” effect that has shown utility for the slow release of various biologic agents both in vitro and in vivo [ 25 – 27 ]. Here, we showed that GO can be used to exert a sustained release of recombinant human TIMP-1 protein.…”
The purpose of this study was to testify the hypothesis that graphene oxide (GO) could act as an appropriate vehicle for the release of tissue inhibitors of metalloproteinase-1 (TIMP-1) protein in the context of skin repair. GO characteristics were observed by scanning electron microscopy, atomic force microscopy, and thermal gravimetric analysis. After TIMP-1 absorbing GO, the release profiles of various concentrations of TIMP-1 from GO were compared. GO biocompatibility with fibroblast viability was assessed by measuring cell cycle and apoptosis. In vivo wound healing assays were used to determine the effect of TIMP-1-GO on skin regeneration. The greatest intensity of GO was 1140 nm, and the most intensity volume was 10,674.1 nm (nanometer). TIMP-1 was shown to be continuously released for at least 40 days from GO. The proliferation and viability of rat fibroblasts cultured with TIMP-1-GO were not significantly different as compared with the cells grown in GO or TIMP-1 alone (p > 0.05). Skin defect of rats treated with TIMP-1 and TIMP-1-GO showed significant differences in histological and immunohistochemical scores (p < 0.05). GO can be controlled to release carrier materials. The combination of TIMP-1 and GO promoted the progression of skin tissue regeneration in skin defect.
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