Polymer-Ag Nanocomposites with Enhanced Antimicrobial Activity against Bacterial Infection

Herein, a nontoxic nanocomposite is synthesized by reduction of silver nitrate in the presence of a cationic polymer displaying strong antimicrobial activity against bacterial infection. These nanocomposites with a large concentration of positive charge promote their adsorption to bacterial membranes through electrostatic interaction. Moreover, the synthesized nanocomposites with polyvalent and synergistic antimicrobial effects can effectively kill both Gram-positive and Gram-negative bacteria without the emergence of bacterial resistance. Morphological changes obtained by transmission electron microscope observation show that these nanocomposites can cause leakage and chaos of intracellular contents. Analysis of the antimicrobial mechanism confirms that the lethal action of nanocomposites against the bacteria started with disruption of the bacterial membrane, subsequent cellular internalization of the nanoparticles, and inhibition of intracellular enzymatic activity. This novel antimicrobial material with good cytocompatibility promotes healing of infected wounds in diabetic rats, and has a promising future in the treatment of other infectious diseases

Atomic-Scale Control of Silicon Expansion Space as Ultrastable Battery Anodes

Development of electrode materials with high capability and long cycle life are central issues for lithium-ion batteries (LIBs). Here, we report an architecture of three-dimensional (3D) flexible silicon and graphene/carbon nanofibers (FSiGCNFs) with atomic-scale control of the expansion space as the binder-free anode for flexible LIBs. The FSiGCNFs with Si nanoparticles surrounded by accurate and controllable void spaces ensure excellent mechanical strength and afford sufficient space to overcome the damage caused by the volume expansion of Si nanoparticles during charge and discharge processes. This 3D porous structure possessing built-in void space between the Si and graphene/carbon matrix not only limits most solid-electrolyte interphase formation to the outer surface, instead of on the surface of individual NPs, and increases its stability but also achieves highly efficient channels for the fast transport of both electrons and lithium ions during cycling, thus offering outstanding electrochemical performance (2002 mAh g^–1 at a current density of 700 mA g^–1 over 1050 cycles corresponding to 3840 mAh g^–1 for silicon alone and 582 mAh g^–1 at the highest current density of 28 000 mA g^–1)

Additional file 1 of Identification of candidate genes and chemicals associated with osteoarthritis by transcriptome-wide association study and chemical-gene interaction analysis

Additional file 1

Targeting Chemophotothermal Therapy of Hepatoma by Gold Nanorods/Graphene Oxide Core/Shell Nanocomposites

Nanographene oxide (NGO) are highly suitable to be the shells of inorganic nanomaterials to enhance their biocompatibility and hydrophilicity for biomedical applications while retaining their useful photonic, magnetic, or radiological functions. In this study, a novel nanostructure with gold nanorods (AuNRs) encapsulated in NGO shells is developed to be an ultraefficient chemophotothermal cancer therapy agent. The NGO shells decrease the toxicity of surfactant-coated AuNRs and provide anchor points for the conjugation of hyaluronic acid (HA). The HA-conjugated NGO-enwrapped AuNR nanocomposites (NGOHA-AuNRs) perform higher photothermal efficiency than AuNRs and have the capability of targeting hepatoma Huh-7 cells. NGOHA-AuNR is applied to load doxorubicin (DOX), and it exhibits pH-responsive and near-infrared light-triggered drug-release properties. Chemophotothermal combined therapy by NGOHA-AuNRs-DOX performs 1.5-fold and 4-fold higher targeting cell death rates than single chemotherapy and photothermal therapy, respectively, with biosafety to nontargeting cells simultaneously. Furthermore, our strategy could be extended to constructing other NGO-encapsulated functional nanomaterial-based carrier systems

Vps35-deficiency impairs SLC4A11 trafficking and promotes corneal dystrophy

<div><p>Vps35 (vacuolar protein sorting 35) is a major component of retromer that selectively promotes endosome-to-Golgi retrieval of transmembrane proteins. Dysfunction of retromer is a risk factor for the pathogenesis of Parkinson’s disease (PD) and Alzheimer’s disease (AD). However, Vps35/retromer’s function in the eye or the contribution of Vps35-deficiency to eye degenerative disorders remains to be explored. Here we provide evidence for a critical role of Vps35 in mouse corneal dystrophy. Vps35 is expressed in mouse and human cornea. Mouse cornea from Vps35 heterozygotes (Vps35^+/-) show features of dystrophy, such as loss of both endothelial and epithelial cell densities, disorganizations of endothelial, stroma, and epithelial cells, excrescences in the Descemet membrane, and corneal edema. Additionally, corneal epithelial cell proliferation was reduced in Vps35-deficient mice. Intriguingly, cell surface targeting of SLC4A11, a membrane transport protein (OH^- /H⁺ /NH₃ /H₂O) of corneal endothelium, whose mutations have been identified in patients with corneal dystrophy, was impaired in Vps35-deficient cells and cornea. Taken together, these results suggest that SLC4A11 appears to be a Vps35/retromer cargo, and Vps35-regulation of SLC4A11 trafficking may underlie Vps35/retromer regulation of corneal dystrophy.</p></div

Abnormality of corneal morphology in Vps35^+/- cornea.

<p><b>(A)</b> H & E staining analysis of cross sections of retina and cornea from P90 old Vps35^+/+ and Vps35^+/- mice. a and a’: retina from Vps35^+/+ and ^+/- mice, respectively; b and b’: cornea from Vps35^+/+ and ^+/- mice, respectively. <b>(B)</b> Higher power magnification of H & E staining analysis of cornea from Vps35^+/+ and ^+/- mice at indicated ages. Cells’ nuclei in stroma and endothelium were marked with dotted lines. <b>(C–F)</b> Quantification analyses of data from <b>(B)</b>. Epithelium cell density was decreased in Vps35 ^+/- cornea <b>(C)</b>; Endothelium thickness <b>(F)</b>, stroma thickness <b>(D)</b>, and stroma cell density <b>(E)</b> were all increased in Vps35 ^+/- cornea. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer; OS, outer segment; IS, inner segment. Epi, corneal epithelium; St, corneal stroma; Endo, corneal endothelium. Scale bars, 100 μm.</p

Impaired cell surface targeting of SLC4A11 in Vps35-deficient cells and reduced SLC4A11 in Vps35-deficient corneal endothelium.

<p><b>(A-G)</b> HEK293 cells transfected with SLC4A11-GFP with control and miRNA-Vps35 were subjected to co-immunstaining analyses using indicated antibodies. Representative confocal images were shown in (A and D); and quantification analyses (mean +/- SEM, n = 20 cells, *, p<0.05) were presented in (B-C, E-G). Scale bars, 20 μm. <b>(H)</b> Co-Immunostaining analysis using anti-SLC4A11 and β-gal antibodies of cross-mounted cornea from P30 Vps35^+/+ and ^+/- mice. Scale bars, 20 μm. <b>(I-J)</b> Immunostaining analysis using anti-SLC4A11 antibodies of flat-mounted cornea from P30 and P90 Vps35^+/+ and ^+/- mice. Scale bars, 20 μm. Epi, corneal epithelium; St, corneal stroma; Endo, corneal endothelium. Representative images were shown in (I), and Quantification analysis was presented in (J) (mean +/- SEM, n = 4 mice/each group, *, p<0.05).</p

Reduced SLC4A11 co-localization with Vps35/retromer and SLC4A11 cell surface targeting by corneal dystrophy-linked SLC4A11 mutations.

<p>Illustration of a working hypothesis for Vps35 regulation of SLC4A11, which may underlie Vps35’s involvement of corneal dystrophy.</p

Direct Room Temperature Welding and Chemical Protection of Silver Nanowire Thin Films for High Performance Transparent Conductors

Silver nanowire (Ag-NW) thin films have emerged as a promising next-generation transparent electrode. However, the current Ag-NW thin films are often plagued by high NW–NW contact resistance and poor long-term stability, which can be largely attributed to the ill-defined polyvinyl­pyrrolidone (PVP) surface ligands and nonideal Ag–PVP–Ag contact at NW–NW junctions. Herein, we report a room temperature direct welding and chemical protection strategy to greatly improve the conductivity and stability of the Ag-NW thin films. Specifically, we use a sodium borohydride (NaBH₄) treatment process to thoroughly remove the PVP ligands and produce a clean Ag–Ag interface that allows direct welding of NW–NW junctions at room temperature, thus greatly improving the conductivity of the Ag-NW films, outperforming those obtained by thermal or plasmonic thermal treatment. We further show that, by decorating the as-formed Ag-NW thin film with a dense, hydrophobic dodecanethiol layer, the stability of the Ag-NW film can be greatly improved by 150-times compared with that of PVP-wrapped ones. Our studies demonstrate that a proper surface ligand design can effectively improve the conductivity and stability of Ag-NW thin films, marking an important step toward their applications in electronic and optoelectronic devices

Ultrahigh Sensitivity of Au/1D α‑Fe₂O₃ to Acetone and the Sensing Mechanism

Hematite (α-Fe₂O₃) is a nontoxic, stable, versatile material that is widely used in catalysis and sensors. Its functionality in sensing organic molecules such as acetone is of great interest because it can result in potential medical applications. In this report, microwave irradiation is applied in the preparation of one-dimensional (1D) α-FeOOH, thereby simplifying our previous hydrothermal method and reducing the reaction time to just a few minutes. Upon calcination, the sample was converted to porous α-Fe₂O₃ nanorods, which were then decorated homogeneously by fine Au particles, yielding Au/1D α-Fe₂O₃ at nominally 3 wt % Au. After calcination, the sample was tested as a potential sensor for acetone in the parts per million range and compared to a similarly loaded Pt sample and the pure 1D α-Fe₂O₃ support. Gold addition results in a much enhanced response whereas Pt confers little or no improvement. From tests on acetone in the 1–100 ppm range in humid air, Au/1D α-Fe₂O₃ has a fast response, short recovery time, and an almost linear response to the acetone concentration. The optimum working temperature was found to be 270 °C, which was judged to be a compromise between the thermal activation of lattice oxygen in hematite and the propensity for acetone adsorption. The surface reaction was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and a possible sensing mechanism is proposed. The presence of Au nanoparticles is believed to promote the dissociation of molecular oxygen better in replenishing O vacancies, thereby increasing the instantaneous supply of lattice oxygen to the oxidation of acetone (to H₂O and CO₂), which proceeds through an adsorbed acetate intermediate. This work contributes to the development of next-generation sensors, which offer ultrahigh detection capabilities for organic molecules