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Objective(s): Nowadays, the unique and fascinating properties of graphene-based nanocomposites make them one of the most promising materials for therapeutics, delivery carriers as well as tissue engineering. On the other hand, silver nanowire has been attracting more attention in nanomedicine applications, too. In this study, the effects of synthesized silver nanowire/reduced graphene oxide (AgNWs/rGO) composites on the structure and esterase-like activity of Human Serum Albumin (HSA), as well as its impacts on Human Endometrial Stem Cells (hEnSCs), were evaluated. Materials and Methods: AgNWs/rGO composite was first synthesized and fabricated. Subsequently, its effects on the structure and esterase-like activity of HSA were evaluated by UV-Visible spectroscopy, circular dichroism spectroscopy, and fluorescence spectroscopy. Afterward, its impacts on the viability and growth of hEnSCs were studied by MTT assay, DAPI staining, and flow cytometry analysis. Results: The spectroscopic results showed that AgNWs/rGO composite could form a complex with HSA, however, did not affect the secondary structure of HSA and the binding constant for this complex was found to be 5.4×104 mL.mg-1. Furthermore, HSA maintained most of its activity in the presence of the AgNWs/rGO composite. Based on FRET (fluorescence resonance energy transfer) data the value of r0 was less than 7 nm signifying that the energy transfer from HSA to AgNWs/rGO composite occurs with a high level of possibility. The MTT assay, DAPI staining, and flow cytometry analysis indicated that the AgNWs/rGO composite was non-toxic towards hEnSCs. Conclusion: Our results suggest that the prepared AgNWs/rGO composite, potentially, is suitable in nanomedicine applications such as tissue engineering and drug delivery. [ABSTRACT FROM AUTHOR]

While camphorsulfonic acid (CSA) has been introduced as a common dopant of polyaniline (PANi), detachment of CSA from PANi reduces cell proliferation as a function of resultant acidic media. Herein, Graphene oxide (GO) nanosheets due to their biocompatible nature and long pairs of electrons on oxygen atoms had been employed as a dopant. The corresponding particles were imbedded in PANi scaffold at a biocompatible concentration and the composite scaffold of PANi-NPs were modified using plasma treatment to obtain hydrophilic surface for cells attachment. GO nanoparticles kept the interaction with PANi in physiological pH and hence, the cell proliferation on composite scaffold showed optimum value of biocompatibility compared to non-composite and control group. Also Fourier-transform infrared spectroscopy (FTIR) assay confirmed the electrostatic/hydrogen bonds between GO nanosheets and PANi. The better cell adhesion, higher gene expression and stronger positive result of protein markers with composite scaffold exposed efficient interactions of GO nanoparticles with PANi over cell studies process. [ABSTRACT FROM AUTHOR]

Mimicking the extracellular matrix to have a similar nanofibrous structure regarding electrical conductivity and mechanical properties would be highly beneficial for cardiac tissue engineering. The molybdenum disulfide, MoS2, and reduced graphene oxide, rGO, nanosheets are two‐dimensional nanomaterials which can be considered as great candidates for enhancing the electrical and mechanical properties of biological scaffolds for cardiac tissue engineering applications. In this study, MoS2 and rGO nanosheets were synthesized and incorporated into silk fibroin nanofibers, SF, via electrospinning method. Then, the human iPSCs transfected with TBX‐18 gene, TBX18‐hiPSCs, were seeded on these scaffolds for in vitro studies. The MoS2 and rGO nanosheets were studied by Raman spectroscopy. After incorporation of the nanosheets into SF nanofibers, the associated characterizations were carried out including scanning electron microscopy, transmission electron microscopy, water contact angle, and mechanical test. Furthermore, SF, SF/MoS2, and SF/rGO scaffolds were used for in vitro studies. Herein, the scaffolds exhibited acceptable biocompatibility and considerable attachment to TBX18‐hiPSCs confirmed by 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyl tetrazolium bromide, MTT, assay, and scanning electron microscopy. Also, the real‐time PCR and immunostaining studies confirmed the maturity and upregulation of cardiac functional genes, including GATA‐4, c‐TnT, and α‐MHC in the SF/MoS2 and SF/rGO scaffolds compared with the bare SF one. Therefore, the reinforcement of these SF‐based scaffolds with MoS2 and rGO endues them as a suitable candidate for cardiac tissue engineering. [ABSTRACT FROM AUTHOR]

This paper reports on a novel low-temperature method for preparing curcumin-reduced graphene oxide (Cur-rGO) from graphene oxide (GO) and investigates their cyclic voltammetry (CV) and photoluminescence (PL) properties. GO sheets were synthesized using modified Hummers' method and then were chemically reduced using polyphenol curcumin into graphene sheets. Atomic force microscopy, transmission electron microscopy and x-ray photoelectron spectroscopy were used to confirm the formation of Cur-rGO and revealed their functionalization with polyphenol curcumin. The electrochemical and optical properties of the Cur-rGO sheets were investigated using CV and PL spectroscopy. According to the PL and CV characterization for the Cur-rGO sheets, charges and resonant energy were transferred from curcumin molecules to the GO sheets' surfaces. This arises from the bonding of the fluorescence curcumin molecules to the Cur-rGO surfaces, through π-π stacking of their aromatic rings. It should be noted that curcumin molecules act as electron donors, suppressing the fluorescence of the GO sheets while improving their electrochemical activities. [ABSTRACT FROM AUTHOR]