Gold nanorods, rod-shaped gold nanoparticles, have transverse and longitudinal surface plasmon (SP) bands at visible and near-infrared (IR) regions, respectively. Since the absorbed light energy is converted into heat, photothermal effect of gold nanorods can be triggered without damaging the tissues in the path of near-IR laser light. In this study, we tried to construct controlled release system of functional molecules from surface of gold nanorods mediated by the photothermal effect. First, we evaluated controlled release of poly(ethyleneglycol) (PEG) chains from PEG-modified gold nanorods (PEG-NR). Next, we employed double stranded oligonucleotide as a thermo-responsive dissociating group (DNA-NR). Finally, we evaluated photothermal release of PEG chains mediated retro-Diels-Alder reaction (PEG-DA-NR). For construction of controlled release system of functional molecules, these studies will provide important information about the photothermal reactions of surface molecules on the gold nanorods triggered by near-IR light irradiation.

A cationic peptide dendrier, dendritic poly(L-lysine), forms complexes with oligonucleotides and can deliver them to liver after intravenous injection. Here, we tried to deliver apolipoprotein B-specific siRNA for the treatment of hypercholesterolemia and NFκB decoy for the hepatitis treatment. Significant therapeutic effects in those disease model mice were observed after intravenous injection of the oligonucleotides complexes with dendritic poly(L-lysine).

We have developed new gene expression-regulating polymer that can activate transgene expression in response to target intracellular signals. Here, we tried applying sonoporation system to this gene regulation system to enhance the gene expression efficacy. Sonoporation is the method for effective gene transfection in vitro and in vivo. Therefore, the method might enhance the transfection efficiency in our polymer and realize an efficient and safe gene delivery system. Results suggested that the combination of our polymer and sonoporation could improve the gene expression compared to the system using only our polymer that transfers genes into cells via endocytosis. It also kept the ability of the gene regulation responding to cellular signals.

Balloon dilation was performed in four patients with postoperative pulmonary stenosis who had undergone surgical creation of a coronary arterial tunnel in the pulmonary trunk. Two patients had complete transposition in whom the arterial switch operation had been performed using the modified Aubert method. The other two patients had anomalous origin of the left coronary artery from the pulmonary trunk treated with the Takeuchi procedure. Balloon dilation was performed at 11 locations. The pressure gradient decreased from 48 ± 22 to 24 ± 14mmHg (p<0.01), and the diameter of the narrowest segment increased from 5.3 ± 2.5 to 7.5 ± 2.8mm (p<0.01), respectively. Of the 11 procedures, 8 (73%) were judged successful with use of the criterion of success as a greater than 50% decrease in pressure gradient, and/or a greater than 50% increase in diameter. The inflated balloon must have compressed the coronary arterial tunnel in the pulmonary trunk, but there was no apparent myocardial damage in any patient, although transient and mild ST-T changes appeared on electrocardiographic monitoring during the procedure in 2 patients. Rupture of the wall of the pulmonary trunk occurred in two patients, one of whom required elective surgical intervention. These data suggest that balloon dilation should be performed with caution for management of postoperative pulmonary arterial stenosis in patients with a surgically created intrapulmonary coronary arterial tunnel, since tearing the wall of the pulmonary trunk may occur.

Gold nanorods have a strong surface plasmon band at the near infrared region. The absorbed light energy is then converted to heat. Since near infrared light can penetrate deeply into tissue, gold nanorods are expected to be used as a contrast agent for bioimaging using the near infrared light and photosensitizers for photothermal therapy. The surface plasmon bands of intravenously injected the gold nanorods were directly monitored from the mouse abdomen by using a spectrophotometer equipped with an integrating sphere. The absorbance at 900 nm from PEG5,000-modified gold nanorods immediately increased after injection and reached a plateau. The injection of phosphatidylcholine-modified gold nanorods also increased the absorbance at 900 nm, but the absorbance decreased single exponentially with a 1.3-min half-life. To demonstrate photothermal tumor therapy, the PEG-modified gold nanorods were directly injected into subcutaneous tumors in mice, then, near infrared laser light was irradiated to the tumor. After the treatment, significant suppression of tumor growth was observed.

Hexabenzocoronene (HBC) derivatives that are designed to self-assemble into lamellar aggregates were synthesized. The derivatives were deposited as an active layer in an organic field-effect transistor (OFET) using vacuum sublimation. The dihexyl and tetrahexyl derivatives (2H-HBC, 4H-HBC) increased the field-effect mobilities and on/off ratios by a factor of 10 or more compared to unsubstituted HBC and hexahexyl-hexabenzocoronene (6H-HBC). The crystal and thin film structures were determined by powder x-ray diffraction and grazing incidence X-ray diffraction (GIXD). The data indicate that 2H-HBC and 4H-HBC self-assemble into lamellar aggregates. 2H-HBC forms layers of aromatic cores that are sandwiched by the layers of hexyl groups, which is a preferable crystal structure for carrier transport. The good OFET performance could be explained by the self-assembly in lamellar aggregates of 2H-HBC and 4H-HBC, in contrast to self-assembly in the columnar aggregate of 6H-HBC and the low self-assembling properties of unsubstituted HBC.

High-energy protons are generated by focusing an ultrashort pulsed high intensity laser at the Advanced Photon Research Center, JAERI-Kansai onto thin (thickness <10 μm) Tantalum targets. The laser intensities are about 4 × 1018 W/cm2. The prepulse level of the laser pulse is measured with combination of a PIN photo diode and a cross correlator and is less than 10−6. A quarter-wave plate is installed into the laser beam line to create circularly polarized pulses. Collimated high energy protons are observed with CH coated Tantalum targets irradiated with the circularly polarized laser pulses. The beam divergence of the generated proton beam is measured with a CR-39 track detector and is about 6 mrad.