The power of bioluminescence imaging in understanding host-pathogen interactions

Infectious diseases are one of the leading causes of death worldwide. Modelling and understanding human infection is imperative to developing treatments to reduce the global burden of infectious disease. Bioluminescence imaging is a highly sensitive, non-invasive technique based on the detection of light, produced by luciferase-catalysed reactions. In the study of infectious disease, bioluminescence imaging is a well-established technique; it can be used to detect, localize and quantify specific immune cells, pathogens or immunological processes. This enables longitudinal studies in which the spectrum of the disease process and its response to therapies can be monitored. Light producing transgenic rodents are emerging as key tools in the study of host response to infection. Here, we review the strategies for identifying biological processes in vivo, including the technology of bioluminescence imaging and illustrate how this technique is shedding light on the host-pathogen relationship

Polyethylenimine-Dermatan Sulfate Complex, a Bioactive Biomaterial with Unique Toxicity to CD146-Positive Cancer Cells

We report unique bioactivity of a polycation-polyanion complex with potential utility for cancer therapy. A complex of disulfide-cross-linked polyethylenimine (CLPEI), a polycation used for gene complexation, and dermatan sulfate (DS), an anionic polysaccharide to shield excessive cationic charge of the former, has toxicity to a specific group of cancer cell lines, including B16-F10 murine melanoma, A375SM human melanoma, and PC-3 human prostate cancer cells. These CLPEI-DS-sensitive cells express CD146, which binds to the complex via interaction with DS. There is a positive correlation between toxicity and intracellular level of CLPEI, indicating that the CLPEI-DS-sensitivity is attributable to the increased cellular uptake of CLPEI mediated by the DS-CD146 interactions. In vitro studies show that CLPEI-DS complex causes G₀/G₁ phase arrest and apoptotic cell death. In syngeneic and allograft models of B16-F10 melanoma, CLPEI-DS complex administered with a subtoxic level of doxorubicin potentiates the chemotherapeutic effect of the drug by loosening tumor tissues. Given the unique toxicity, CLPEI-DS complex may be a useful carrier of gene or chemotherapeutics for the therapy of CD146-positive cancers

Facile Preparation of Zwitterion-Stabilized Superparamagnetic Iron Oxide Nanoparticles (ZSPIONs) as an MR Contrast Agent for in Vivo Applications

We describe a simple method for synthesizing superparamagnetic nanoparticles (SPIONs) as small, stable contrast agents for magnetic resonance imaging (MRI) based on sulfobetaine zwitterionic ligands. SPIONs synthesized by thermal decomposition were coated with zwitterions to impart water dispersibility and high in vivo stability through the nanoemulsion method. Zwitterion surfactant coating layers are formed easily on oleic acid-stabilized SPIONs via hydrophobic and van der Waals interactions. Our zwitterion-coated SPIONs (ZSPIONs) had ultrathin (∼5 nm) coating layers with mean sizes of 12.0 ± 2.5 nm, as measured by dynamic light scattering (DLS). Upon incubation in 1 M NaCl and 10% FBS, the ZSPIONs showed high colloidal stabilities without precipitating, as monitored by DLS. The T2 relaxivity coefficient of the ZSPIONs, obtained by measuring the relaxation rate on the basis of the iron concentration, was 261 mM^–1s^–1. This value was much higher than that of the commercial T2 contrast agent because of the ultrathin coating layer. Furthermore, we confirmed that ZSPIONs can be used as MR contrast agents for in vivo applications such as tumor imaging and lymph node mapping

Nonvacuum, Maskless Fabrication of a Flexible Metal Grid Transparent Conductor by Low-Temperature Selective Laser Sintering of Nanoparticle Ink

We introduce a facile approach to fabricate a metallic grid transparent conductor on a flexible substrate using selective laser sintering of metal nanoparticle ink. The metallic grid transparent conductors with high transmittance (>85%) and low sheet resistance (30 Ω/sq) are readily produced on glass and polymer substrates at large scale without any vacuum or high-temperature environment. Being a maskless direct writing method, the shape and the parameters of the grid can be easily changed by CAD data. The resultant metallic grid also showed a superior stability in terms of adhesion and bending. This transparent conductor is further applied to the touch screen panel, and it is confirmed that the final device operates firmly under continuous mechanical stress

Additional file 2: Table S1. of Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells

Primers used in RT-PCR analysis. Table S2 Primers used in ATP7A genotyping of MD-derived cells. Table S3 Primers used in methylation analysis. Table S4 Copper concentration in WT- and MD-MSCs. (DOCX 19 kb

Additional file 5: Figure S4. of Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells

Characterization of EBs during MSC differentiation. (A) SMAD2 phosphorylation in WT- and MD-EBs during MSC differentiation. SB treatment suppressed p-SMAD2 in WT- and MD-EBs. (B) Relative expression of neuro-ectoderm and cardiac mesoderm marker genes (NEUROD1 and cTNT, respectively) in WT- and MD-EBs. The data are presented as the mean Âą SE (n = 3); *p < 0.05, **p < 0.01. (TIFF 2052 kb

Additional file 7: Figure S6. of Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells

Relative expression of ATP7A after siRNA transfection. The data are represented as the mean Âą SE (n = 3); **p < 0.01. (TIFF 326 kb

Additional file 6: Figure S5. of Impaired osteogenesis in Menkes disease-derived induced pluripotent stem cells

Confirmation of MD-MSCs. (A) Genetic mutation of the ATP7A gene in MD1-MSCs. A single-base substitution was confirmed again in MD1-MSCs. (B) Genetic mutation of the ATP7A gene in MD2-MSCs. Size differences in the PCR product were observed in MD2-MSCs. (C) Expression of ATP7A in WT- and MD-MSCs. ATP7A protein was not detected in MD1- and MD2-MSCs. (TIFF 936 kb

Direct O–O Coupling Promoted the Oxygen Evolution Reaction by Dual Active Sites from Ag/LaNiO₃ Interfaces

The development of highly active oxygen evolution reaction (OER) electrocatalysts is one of the most important issues for advanced water electrolysis technology with high energy efficiency. However, according to the conventional adsorbate evolution mechanism (AEM), the OER activity is theoretically limited with high overpotential by the scaling relationship in binding energies of the reaction intermediates. We propose an attractive strategy to promote OER activity by direct O–O coupling at the interfacial active sites for Ag (x) nanoparticles decorated on La1–xNiO3 perovskite electrocatalysts (Ag/LNO-x). The overpotential of the Ag/LNO-0.05 was 315 mV at a current density of 10 mA cm–2geo, which was much lower than that of other Ag/LNO-x (x = 0, 0.3, and 0.5) and commercial iridium oxide (IrO2, 398 mV) electrocatalysts. The theoretical calculation revealed that the improved OER electrocatalytic activity of Ag/LNO-x originated from a change in the reaction mechanism at the interfacial active sites. At the interface, oxygen evolution via the dual-site mechanism with direct O–O coupling becomes more favorable than that via the conventional AEM. Finally, due to the formation of the interfacial active sites, the synthesized Ag/LNO-0.05 electrocatalyst showed significantly enhanced OER activity, which was 20 times higher mass activity before and 74 times after an accelerated durability test than that of the IrO2 electrocatalyst