Sharif Digital Repository

Single-layer reduced graphene oxide nanoribbons (rGONRs) were obtained through an oxidative unzipping of multi-walled carbon nanotubes and a subsequent deoxygenation by hydrazine and bovine serum albumin. Human mesenchymal stem cells (hMSCs) were isolated from umbilical cord blood and used for checking the concentration- and time-dependent cyto- and geno-toxic effects of the rGONRs and reduced graphene oxide sheets (rGOSs). The cell viability assay indicated significant cytotoxic effects of 10 μg/mL rGONRs after 1 h exposure time, while the rGOSs exhibited the same cytotoxicity at concentration of 100 μg/mL after 96 h. The oxidative stress was found as the main mechanism involved in the... 

Reduced graphene oxide nanoribbons functionalized by amphiphilic polyethylene glycol (rGONR-PEG) were applied to attach arginine-glycine-aspartic acid (RGD)-based peptide and cyanine dye 3 (cy3) for targeting ανβ3 integrin receptors on human glioblastoma cell line U87MG and its selective fluorescence imaging, respectively. The rGONR-PEG suspension with a concentration of 100 μg mL -1 showed ∼14 and 2.4-fold higher near infrared (NIR) absorption at 808 nm than GONR (with dimensions of ∼80 nm × 1 μm) and rGO-PEG sheets (with lateral dimensions of ∼2 μm), respectively. The rGONR-PEG-cy3-RGD exhibited highly efficient NIR photothermal therapy performance (concentrations ≥1.0 μg mL-1 resulted in... 

In this study, a dielectrophoresis field-flow fractionation device was analyzed using a numerical simulation method and the behaviors of a set of different cells were investigated. By reducing the alternating current frequency of the electrodes from the value used in the original setup configuration and increasing the number of exit channels, total discrimination in cell trajectories and subsequent separation of four cell types were achieved. Cells were differentiated based on their size and dielectric response that are represented in their real part of Clausius–Mossotti factor at different frequencies. A number of novel designs were also proposed based on the original setup configuration.... 

Reduced graphene oxide nanoplatelets (rGONPs) were synthesized by sonication of covalently PEGylated GO sheets followed by a chemical reduction using hydrazine and bovine serum albumin. Human mesenchymal stem cells (hMSCs), as a fundamental factor in tissue engineering, were isolated from umbilical cord blood (as a recently proposed source for extracting fresh hMSCs) to investigate, for the first time, the size-dependent cyto- and geno-toxic effects of the rGONPs on the cells. The cell viability test showed significant cell destructions by 1.0 μg/mL rGONPs with average lateral dimensions (ALDs) of 11±4 nm, while the rGO sheets with ALDs of 3.8±0.4 μm could exhibit a significant cytotoxic...