Development of electrically conductive hybrid nanofibers based on CNT-polyurethane nanocomposite for cardiac tissue engineering

Conductive nanofibers have been considered as one of the most interesting and promising candidate scaffolds for cardiac patch applications with capability to improve cell-cell communication. Here, we successfully fabricated electroconductive nanofibrous patches by simultaneous electrospray of multiwalled carbon nanotubes (MWCNTs) on polyurethane nanofibers. A series of CNT/PU nanocomposites with different weight ratios (2:10, 3:10, and 6:10wt%) were obtained. Scanning electron microscopy, conductivity analysis, water contact angle measurements, and tensile tests were used to characterize the scaffolds. FESEM showed that CNTs were adhered on PU nanofibers and created an interconnected web-like structures. The SEM images also revealed that the diameters of nanofibers were decreased by increasing CNTs. The electrical conductivity, tensile strength, Young's modulus, and hydrophilicity of CNT/PU nanocomposites also enhanced after adding CNTs. The scaffolds revealed suitable cytocompatibility for H9c2 cells and human umbilical vein endothelial cells (HUVECs). This study indicated that simultaneous electrospinning and electrospray can be used to fabricate conductive CNT/PUnanofibers, resulting in better cytocompatibility and improved interactions between the scaffold and cardiomyoblast

Chromium Elimination from Water by use of Iron Oxide Nanoparticles Absorbents

Introduction: In many studies, nanoparticles was used to remediation of heavy metals from water, results of these study showed that these materials have high power in contaminant remediation from aqueous solutions, and bio-absorbents also have high power in water infiltration. The main purpose of this paper is investigation of effects of adding of iron oxides nanoparticles to chrome removal bio-filters. Methods: used method in this study was filtration, also studied variable was absorbent type. Indeed, effect of absorbent type on percent of heavy metals remediation was studied. In two first steps contaminated water with three concentrations (883.7, 1767.4, and 8837 ppm) was remediated with using of soil and sawdust absorbents. In two next steps, for comparison, some iron oxide nanoparticles with several herbaceous absorbents were adding to soil and sawdust absorbents and again absorption was performed. Results: results showed that best absorbent is soil absorbent and iron oxide nanoparticles, with maximum removal percent equal to 96.2%. Also best turnover was obtained from 8837 ppm of primary concentration of heavy metal. In other hand, in other experiments that used from iron oxide nanoparticles, adding of nanoparticles caused to increase in chrome absorption and conversion of Cr6+ to Cr3+. Conclusion: with use of the results of this study can be said that Combining of iron oxide nanoparticles with chrome removal filters can be convert Cr6+ to Cr3+, and process turnover will increased