Adeno-associated virus-mediated osteoprotegerin gene transfer protects against joint destruction in a collagen-induced arthritis rat model.

OBJECTIVE: To evaluate the in vivo joint protection effect of recombinant adeno-associated virus-mediated gene transfer of human osteoprotegerin (rAAV-hOPG). METHODS: Collagen-induced arthritis (CIA) rat model was established. CIA rats were randomly divided into three groups: CIA control group (PBS), rAAV-EGFP (enhanced green fluorescent protein) group and rAAV-hOPG (100 µL/d) group, which received corresponding intra-articular injection treatment. The thickness of the palms and soles, arthritis index, radiological score, pathological score, bone damage factor and protein expression of inflammatory factors were measured and compared with normal control group rats. RESULTS: Positive fluorescence of frozen section confirmed that rAAV-hOPG was efficiently transduced into the synovial tissues of test rats. In rAAV-hOPG group compared with CIA control group, the radiological score was 30.18% lower (P<0.05); the expression of OPG protein was 93.41% higher (P<0.05); the expression of matrix metalloproteinase-3 (MMP-3) protein was 35.38% lower (P<0.05); however, the expression of IL-1ß was not significant; the scores of pannus and inflammation in rAAV-hOPG group have no significant difference. CONCLUSION: These results suggest that adeno-associated virus-mediated transfer of human osteoprotegerin is effectively transducted into the synovial tissues of CIA model, and protects against articular cartilage and bone destruction, but has no obvious efficiency on inflammation. The results also demonstrate that gene transfer using rAAV-hOPG may be a feasible and effective therapeutic candidate to treat or prevent joint destruction in inflammatory arthritis.

Single crystalline Ge(1-x)Mn(x) nanowires as building blocks for nanoelectronics.

Magnetically doped Si and Ge nanowires have potential application in future nanowire spin-based devices. Here, we report a supercritical fluid method for producing single crystalline Mn-doped Ge nanowires with a Mn-doping concentration of between 0.5-1.0 atomic % that display ferromagnetism above 300 K and a superior performance with respect to the hole mobility of around 340 cm(2)/Vs, demonstrating the potential of using these nanowires as building blocks for electronic devices.

Crystal orientation-ordered ZnO nanorod bundles on hexagonal heads of ZnO microcones: epitaxial growth and self-attraction.

We demonstrate a preferential nucleation, epitaxial growth, and self-attraction of crystal orientation-ordered ZnO nanorod bundles on (0001) plane of single-crystal ZnO microcones.

Controllable template synthesis of Ni/Cu nanocable and Ni nanotube arrays: a one-step coelectrodeposition and electrochemical etching method.

We describe a new synthetic approach to fabricate Ni/Cu nanocable arrays by co-depositing nickel and copper atoms into the pores of anodic alumina membranes and to fabricate Ni nanotube arrays by selectively etching the Cu cores from the Ni/Cu nanocable arrays. The formation of the Ni-shelled Ni/Cu nanocables is attributed to the Ni ions adsorbed on the pore walls by a chemical complexation through hydroxyl groups. By varying electrodepositon parameters in this technique, we can control the lengths of nanocables and nanotubes, the shell thickness of the nanocables, and the wall thickness and surface morphology of the nanotubes.

Controllable synthesis and optical properties of novel ZnO cone arrays via vapor transport at low temperature.

Novel ZnO cone arrays with controllable morphologies have been synthesized on silicon (100) substrates by thermal evaporation of metal Zn powder at a low temperature of 570 degrees C without a metal catalyst. Clear structure evolutions were observed using scanning electron microscopy: well-aligned ZnO nanocones, double-cones with growing head cones attached by stem cones, and cones with straight hexagonal pillar were obtained as the distance between the source and the substrates was increased. X-ray diffraction shows that all cone arrays grow along the c-axis. Raman and photoluminescence spectra reveal that the optical properties of the buffer layer between the ZnO cone arrays and the silicon substrates are better than those of the ZnO cone arrays due to high concentration of Zn in the heads of the ZnO cone arrays and higher growth temperature of the buffer layer. The growth of ZnO arrays reveals that the cone arrays are synthesized through a self-catalyzed vapor-liquid-solid (VLS) process.

Synthesis and Characterization of Aligned ZnO Nanorods on Porous Aluminum Oxide Template.

Aligned high-density ZnO nanorods were successfully synthesized on porous aluminum oxide (PAO) template. The growth process involves carbonthermal reduction of ZnO as a Zn vapor source and ZnO nucleation on the PAO template without metal catalysts. Field-emission scanning electron microscope images revealed that the nanorods have uniform length distributions and hexagon end planes, and the intense c-axis growth was also confirmed by X-ray diffraction. Strong ultraviolet emission at 380 nm and weak green band emission at 520 nm at room-temperature photoluminescence clearly indicated the high quality of the ZnO nanorods. A growth mechanism is proposed that the multipore surface of the PAO template plays a critical role in the nucleation of ZnO in the initial stage of growth, and nanorods grow from the nuclei due to intense ZnO c-axis orientation growth.