Functional analysis.

<p>Panel A. Mean b-wave fERG amplitude (μV) plotted against luminance (cd/m²). The mean ± SE is reported for each experimental group (n = 6 for each group). Dash dot-dot and continuous line represent the trend of LD Control group, respectively. Panel B: Representative fERG response in the three experimental conditions (CeO₂ NP, Saline, Vein) at 3 cd/m². Statistical analysis was performed, for each group versus CeO₂ NP, using one-way ANOVA followed by Tukey test. *P< 0.05.</p

Carbon Nanotubes as Activating Tyrosinase Supports for the Selective Synthesis of Catechols

A series of redox catalysts based on the immobilization of tyrosinase on multiwalled carbon nanotubes has been prepared by applying the layer-by-layer principle. The oxidized nanotubes (ox-MWCNTs) were treated with poly­(diallyl dimethylammonium chloride) (PDDA) and tyrosinase to yield ox-MWCNTs/PDDA/tyrosinase <b>I</b>. Catalysts <b>II</b> and <b>III</b> have been prepared by increasing the number of layers of PDDA and enzyme, while <b>IV</b> was obtained by co-immobilization of tyrosinase with bovine serum albumin (ox-MWCNTs/PDDA/BSA-tyrosinase). Attempts to covalently bind tyrosinase provided weakly active systems. The coating of the enzyme based on the simple layer-by-layer principle has afforded catalysts <b>I–III</b>, with a range of activity from 21 units/mg (multilayer, <b>II</b>) to 66 units/mg (monolayer, <b>I</b>), the best system being catalyst <b>IV</b> (80 units/mg). The novel catalysts were fully characterized by scanning electron microscopy and atomic force microscopy, showing increased activity with respect to that of the native enzyme. These catalysts were used in the selective synthesis of catechols by oxidation of <i>meta</i>- and <i>para</i>-substituted phenols in an organic solvent (CH₂Cl₂) as the reaction medium. It is worth noting that immobilized tyrosinase was able to catalyze the oxidation of very hindered phenol derivatives that are slightly reactive with the native enzyme. The increased reactivity can be ascribed to a stabilization of the immobilized tyrosinase. The novel catalysts <b>I</b> and <b>IV</b> retained their activity for five subsequent reactions, showing a higher stability in organic solvent than under traditional buffer conditions

Microglia and TUNEL images in intravitreal injection.

<p>Panels A-B: “hot spot” region in CeO₂ NP and Saline group; Panels A1-B1: “near hot spot” in CeO₂ NP and Saline; panel C: Control. Abbreviations and arrows as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140387#pone.0140387.g006" target="_blank">Fig 6</a>.</p

Thickness of ONL in all experimental conditions.

<p>Representative sections from superior retina (1 mm from optic disc) of Control (A), CeO₂ NP: (B), Saline: (C), Vein: injected trough the tail vein (D) and LD (E). In all panels nuclei, labelled with propidium iodide, are reported in black and white. Panel F shows ONL thickness as a function of distance from the superior to the inferior edge crossing optic disc. Measurements are expressed as ratio ONL/total retina thickness. Statistical analysis was performed by one-way ANOVA followed by Tukey test for each group versus CeO₂ NP group. Data are shown as mean ± SE; (n = 6 for each group). *P< 0.05, **P<0.01. ONL: outer nuclear layer, INL: inner nuclear layer, GCL: ganglion cell layer.</p

Electronic and structural properties of CeO₂ Nanoparticles.

<p>Decomposition of the XPS Ce 3<i>d</i> core level into Ce³⁺ and Ce⁴⁺ emission (left panel) and XRD pattern (right panel) for the as prepared CeO_<b>2</b> nanoparticles.</p

Microglia and TUNEL images in LD and intravenous injection.

<p>Immunolabelling for microglia (anti-Iba1) in green and apoptotic nuclei in red. The figure shows two different parts of superior retina, in each experimental group, one week after BCL. The arrows indicate the presence of activated microglia in the ONL. Panels A-B: “hot spot” region in LD and Vein; panels A1-B1: “near hot spot” in LD and Vein; panel C: control. ONL: outer nuclear layer, INL: inner nuclear layer, GCL: ganglion cell layer.</p

FITC-CeO₂ nanoparticles in retinal sections labelled with bisbenzimide.

<p>Panels A-B: intravitreal injection of FITC-CeO₂ NPs in rats euthanized after 24 h and after 3 weeks respectively. Panels C-D: injection trough the tail vein of FITC-CeO₂ NPs in rat euthanized after 24 h and after 3 weeks respectively. Images have been acquired with confocal microscopy. In panel B the white rectangle represents the bleaching of FITC-CeO₂ NPs. Scale bars: (A-B-C-D) 50μm. OS: outer segment, ONL: outer nuclear layer, INL: inner nuclear layer, GCL: ganglion cell layer.</p

FGF2 immunolabelling in “hot spot” region.

<p>In panel A: Control, panel B: CeO₂ NP, panel C: Saline, panel D: Vein and panel E: LD, with a scale bar of 50 μm. Panels A1-B1-C1-D1-E1: High magnification with a scale bar of 10 μm. ONL: outer nuclear layer, INL: inner nuclear layer, GCL: ganglion cell layer.</p

TNF-α immunolabelling in “hot spot” region.

<p>Images show the double immunolabelling for microglia (green) and TNF-α (red) in: Control (A), LD (B) and CeO₂ NP (C). The arrow indicates the phagocitic activity of activated microglia in the ONL. Scale bar: 20 μm. ONL: outer nuclear layer, INL: inner nuclear layer, GCL: ganglion cell layer.</p

Analysis of “hot spot” region.

<p>The graph represents the ratio between “hot spot” and superior retina length in the four experimental conditions. Statistical analysis was performed, for each group versus CeO₂ NP group, using one-way ANOVA followed by Tukey test (n = 6 for each experimental group). *P<0.05.</p