Ultrasound-mediated gene and drug delivery using a microbubble-liposome particle system.

Theranostic agents present a promising clinical approach for cancer detection and treatment. We herein introduce a microbubble and liposome complex (MB-Lipo) developed for ultrasound (US) imaging and activation. The MB-Lipo particles have a hybrid structure consisting of a MB complexed with multiple Lipos. The MB components are used to generate high echo signals in US imaging, while the Lipos serve as a versatile carrier of therapeutic materials. MB-Lipo allows high contrast US imaging of tumor sites. More importantly, the application of high acoustic pressure bursts MBs, which releases therapeutic Lipos and further enhances their intracellular delivery through sonoporation effect. Both imaging and drug release could thus be achieved by a single US modality, enabling in situ treatment guided by real-time imaging. The MB-Lipo system was applied to specifically deliver anti-cancer drug and genes to tumor cells, which showed enhanced therapeutic effect. We also demonstrate the clinical potential of MB-Lipo by imaging and treating tumor in vivo.

In vivo quantitative measurement of arthritis activity based on hydrophobically modified glycol chitosan in inflammatory arthritis: more active than passive accumulation.

We demonstrated that arthritis could be visualized noninvasively using hydrophobically modified glycol chitosan nanoparticles labeled with Cy5.5 (HGC-Cy5.5) and an optical imaging system. Activated macrophages expressing Mac-1 molecules effectively phagocytosed HGC-Cy5.5, which formed spherical nanoparticles under physiologic conditions. We estimated the applicability of HGC-Cy5.5 to quantitative analysis of arthritis development and progression. Near-infrared fluorescence images, captured after HGC-Cy5.5 injection in mice with collagen-induced arthritis, showed stronger fluorescence intensity in the active arthritis group than in the nonarthritis group. According to the progression of arthritis in both collagen-induced arthritis and collagen antibody-induced arthritis models, total photon counts (TPCs) increased in parallel with the clinical arthritis index. Quantitative analysis of fluorescence after treatment with methotrexate showed a significant decrease in TPC in a dose-dependent manner. Histologic evaluation confirmed that the mechanism underlying selective accumulation of HGC-Cy5.5 within synovitis tissues included enhanced phagocytosis of the probe by Mac-1-expressing macrophages as well as enhanced permeability through leaky vessels. These results suggest that optical imaging of arthritis using HGC-Cy5.5 can provide an objective measurement of disease activity and, at the same time, therapeutic responses in rheumatoid arthritis.

Preparation of hydrogen titanate nanotube/FTO glass thin film obtained by the layer-by-layer-self assembling method for water splitting.

Hydrogen titanate nanotube (H-TiNT) particles were coated porously on a fluorine-doped tin oxide glass using the layer-by-layer self assembling method and then heat-treated at temperatures below 600 degrees C for 10 min in air. The microstructure, crystallinity, and optical absorbance of the heat-treated H-TiNT thin film were investigated using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and UV-vis spectroscopy, respectively. Also, I-V characteristics of the fibrous H-TiNT particles in the thin film using linear cycle voltammetry under ultraviolet-A irradiation were analyzed to have a maximum current value at applied voltages with the increase in heating temperature for economic water splitting.

Crystalline characterization and photodecomposition properties of rod-shaped Na2Ti6O13 powder prepared by molten salt process.

To prepare one-dimensional nanostructured Na2Ti6O13 powder, the starting materials of TiO2, NaCl and Na2CO3 were mixed and then heat-treated at 1000 degrees C for 2 hrs in air under molten state of NaCl. Changes in shape and phase, photo absorbance and photocatalytic ability of TiO2 particle were observed controlling added amount of Na2CO3 under constant weight ratio of TiO2 to NaCl using SEM, X-ray diffractometer, Raman spectroscopy, and UV-Vis spectroscopy. The TiO2 particle was changed into rod-shape Na2Ti6O13 with the addition of Na2CO3, showing increase in optical energy band-gap of the powder as well as gradual decrease of the photo-decomposition ability.

Understanding for controls of particle shape of various titanates with layered structure.

In this study, various sized and shaped titanates were prepared using rutile phase TiO2 nano-powders in strong basic solution of NaOH having various metallic ions as chlorides by hydrothermal process. Obtained powders were fully characterized using SEM, TEM, XRD, and BET. The XRD results show that all obtained powders have layered structure. However, the shapes of particles doped with Zr4+ and Li+ show nano-belt and nano-plate, respectively, compared to those with nano-tubes of undoped, Ni2+ and Fe3+ doped. These results suggest that particle shape of titanates can be controlled only by small amount of doping elements in NaOH aqueous solutions.

Formation of 1-D nanostructures of titanate thin films and thermal stability study.

One-dimensional (1-D) layered titanate nanotubes and nanoribbon thin films were prepared via the hydrothermal reaction of Ti metal flakes with concentrated NaOH solution. TEM, SEM, and XRD studies of the reaction products revealed that 20-nm-wide and about 1-microm-long nanoribbons formed in 5 M NaOH aqueous solution at 140 degrees C for 12 h, while 6 aproximately 8-nm-wide and several hundred-nanometer-long nanotubes formed with 10 M NaOH. The effect of post treatments on the thermal stablity, phase structure and morphology of the as-prepared nanotubes films was investigated. Different morphologies and crystallinity changes of the as-prepared nanotubes films during heat treatment process are attributed to the sodium impurity.