Cytocompatibility of Graphene Monolayer and Its Impact on Focal Cell Adhesion, Mitochondrial Morphology and Activity in BALB/3T3 Fibroblasts

This study investigates the effect of graphene scaffold on morphology, viability, cytoskeleton, focal contacts, mitochondrial network morphology and activity in BALB/3T3 fibroblasts and provides new data on biocompatibility of the “graphene-family nanomaterials”. We used graphene monolayer applied onto glass cover slide by electrochemical delamination method and regular glass cover slide, as a reference. The morphology of fibroblasts growing on graphene was unaltered, and the cell viability was 95% compared to control cells on non-coated glass slide. There was no significant difference in the cell size (spreading) between both groups studied. Graphene platform significantly increased BALB/3T3 cell mitochondrial activity (WST-8 test) compared to glass substrate. To demonstrate the variability in focal contacts pattern, the effect of graphene on vinculin was examined, which revealed a significant increase in focal contact size comparing to control-glass slide. There was no disruption in mitochondrial network morphology, which was branched and well connected in relation to the control group. Evaluation of the JC-1 red/green fluorescence intensity ratio revealed similar levels of mitochondrial membrane potential in cells growing on graphene-coated and uncoated slides. These results indicate that graphene monolayer scaffold is cytocompatible with connective tissue cells examined and could be beneficial for tissue engineering therapy.

Hydrophobicity and Biofilm Growth ofE-coliRP437, MG1655 and B/r

ABSTRACTTwo strains ofE-ColiK-12, viz, RP437, MG1655 and B/r (E. coliB derivative, not a K-12 strain) were grown on various surfaces to study bacterial adhesion and subsequent biofilm formation. We observed biofilm and large colonies on cover slides, beads made of soda lime or borosilicate glasses, on plasma treated PDMS (Polydimethylsiloxane), on Tissue Culture (TC) polystyrene, and observed some clusters on plasma treated ZnTi cover slide; but no evidence of biofilm on untreated-PDMS and ZnTi glass cover slides. From contact angle measurements, we conclude that the hydrophobic nature of untreated PDMS prevent bacterial adhesion for these three strains.

Size Reduction of Gold Nanoparticles by Pulsed Laser Ablation and Re-Irradiation in Water Media

Gold nanoparticles (Au NPs) were prepared by using pulsed laser ablation with and without cover slide. The cover slide was used to confine atoms/ions in order to reach supersaturation condition. The obtained Au NPs were investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), and zeta potential measurement. The absorbance spectra exhibited its absorption peak at around 520 nm for both Au NPs ablating with and without cover slide. It was found that Au NPs ablating with cover slide exhibited smaller size and size distribution (10.6 ± 5.9 nm) than those of without cover slide (34.1 ± 21.5 nm) at laser power of 5.00 mJ/pulse. This is due to supersaturation effect and re-irradiation effect caused by cover slide that trapped atoms/ions of gold and trapped Au NPs, respectively. Also, the zeta potential of Au NPs had a negative value suggesting negative surface charge. The lowest zeta potential was observed for Au NPs ablating with cover slide at 5.00 mJ/pulse and it was in consistent with an observation of the highest pH value. In addition, the Au NPs ablating with cover slide at 5.00 mJ/pulse showed the least change with time indicating the most stable Au NPs which was in consistent with the lowest zeta potential results. Thus, pulsed laser re-irradiation could be used for size reduction of Au NPs prepared by pulsed laser ablation in water media.

Direct Synthesis of Tungsten Oxide Nanowires on Microscope Cover Glass

A simple technique to synthesis crystalline Tungsten Oxide nanowires is presented. Using a standard thermal hotplate, a pure 99.9% tungsten foil is annealed to 484 ± 5 oC under ambient condition to generate vapor deposition of the heated materials on a piece of 150μm thick glass cover slide pressing on the tungsten foil. Tungsten oxide nanowires are found to deposit on the cover slide facing the heated tungsten foil. These tungsten oxide nanowires were characterized with SEM, TEM, EDX, micro-Raman and XRD. The crystalline nanowires were found to be straight and clean with a diameter of 10-300nm and a length of a few tens of micrometers.

Use of Granada Medium To Detect Group B Streptococcal Colonization in Pregnant Women

Direct inoculation onto Granada medium (GM) in plates and tubes was compared to inoculation into a selective Todd-Hewitt broth (with 8 μg of gentamicin per ml and 15 μg of nalidixic acid per ml) for detection of group B streptococci (GBS) in pregnant women with 800 vaginal and 450 vaginoanorectal samples. Comparatively, GM was found to be as sensitive as the selective broth for the detection of GBS in vaginal specimens and more sensitive than selective broth for the detection of GBS in vaginoanorectal samples (96 versus 82%). The use of GM improved the time to reporting of a GBS-positive result by at least 24 h and reduced the direct cost of screening. We have also found that the inconvenience of anaerobic incubation of GM plates can be avoided when a cover slide is placed upon the inoculum, because aerobic incubation in GM plates with cover slides causes GBS to develop the same pigmentation that it develops with incubation under anaerobic conditions. These data support the routine use of GM plates or tubes as a more accurate, easier, and cheaper method of identification of GBS-colonized women compared to the enrichment broth technique.

Sperm associations in rat epididymis

During epididymal transit a head to head association of spermatozoa has been described in guinea pig, Loris and marsupials. In guinea pig they are permanent and androgen dependent. Other type of sperm association described in nonseasonal. mammals, adopt the stiape of dense masses of degenerating spermatozoa.In the present study a new transitory head to head association in rat spemiatozoa is described which appears at the end of the epididymal transit and dense masses of associated spennatozoa in degeneration similar to those described in the literature. The sperm samples were obtained by puncture of the 3 main epididymal regions. The emerging fluid drops were immediately suspended in a balanced salt solution, placed in a slide-cover slide chanber at 36°C, and observed and recorded with a video equipment. Other drops of epididymal fluid were fixed in Mollenhauer (1976) and processed for light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Polyembryony in Dendrocoelum lacteum O. F. Müller

The development of freshwater Turbellaria has been investigated by few scientists, but the embryonic development of Dendrocoelum lacteum was described in detail by Fuliński (1914, 1916). An experimental analysis of the embryonic development of Dendrocoelum lacteum and Planaria torva has been conducted by Seilern-Aspang (1957, 1958). By placing the contents of a cocoon of Planaria torva on a cover-slide one can observe the course of early development. Certain conditions of culture give rise to deformations of the embryonic rudiments, which in turn leads to polyembryony (Seilern-Aspang, 1957b). The phenomenon of polyembryony also occurs in Procerodes lobata (Seilern-Aspang, (1957a). In our investigations normal polyembryony in Dendrocoelum lacteum has been studied in embryonic development not disturbed by experimental factors. Dendrocoelum lacteum was raised on glass vessels at 20–25° C. The animals were fed on Daphnia and pieces of earthworm. One hundred and ten cocoons were fixed on Zenker's and Serra's fluids and 5μx sections of them were stained by panoptic method of Pappenheim.