Kazuaki Ninomiya

[¹¹¹In]In-diethylenetriaminepentaacetic acid-5,10,15,20-tetraphenylporphyrin ([¹¹¹In]In-DTPA-TPP) nanodroplets were developed for cancer theranostics, featuring ultrasound-sensitive properties. The designed nanodroplets that encapsulate the low-boiling-point liquid perfluorocarbon and IR-780 iodide, a near-infrared fluorescent dye, with surface conjugation of ¹¹¹In-labeled porphyrin derivative, were synthesized and evaluated by in vitro and in vivo experiments. The cellular uptake of [¹¹¹In]In-DTPA-TPP nanodroplets was significantly higher than that of control nanodroplets without TPP. Biodistribution experiments revealed greater tumor accumulation in mice injected with [¹¹¹In]In-DTPA-TPP nanodroplets than in those injected with control nanodroplets lacking TPP. Additionally, the accumulation of [¹¹¹In]In-DTPA-TPP nanodroplets in the tumor was visualized by single-photon emission computed tomography. Sonodynamic therapeutic experiments revealed that DTPA-TPP nanodroplets at 10 µmol total lipids/kg weight with a single ultrasound irradiation onto the tumor area significantly inhibited tumor growth. These results indicate that [¹¹¹In]In-DTPA-TPP nanodroplets would be promising cancer theranostic agents.

The objective of this study was to demonstrate that microwave pretreatment of glycogen-containing Synechococcus elongatus UTEX 2973 could dramatically enhance subsequent enzymatic saccharification and ethanol fermentation. First, the preliminary experiment showed that microwave pretreatment was significantly more effective than either ultrasound pretreatment or lysozyme pretreatment for enzymatic saccharification of intracellular glycogen of S. elongatus UTEX 2973. Next, to investigate the appropriate microwave pretreatment time for enzymatic saccharification of glycogen in S. elongatus UTEX 2973, a cyanobacterial suspension (100 g/L) was pretreated by microwave (200 W) for 0-200 seconds and subjected to the saccharification assay at low biomass loading (10 g/L). The saccharification percentage was only 18% in the case of pretreatment for 0 seconds. On the contrary, the value increased significantly to almost 100% in the case of microwave pretreatment for 100 seconds and more. Finally, to perform saccharification and ethanol fermentation of microwave-pretreated glycogen-containing S. elongatus UTEX 2973, a cyanobacterial suspension (100 g/L) was pretreated by microwave for 0-150 seconds and subjected to enzymatic saccharification, followed by simultaneous saccharification and ethanol fermentation. When the pretreatment time was 150 seconds, the glucose concentration at the end of saccharification was 44 g/L (saccharification percentage of 94%). And the ethanol concentration was 21 g/L during the simultaneous saccharification and fermentation, which is 88% of the theoretical value.

While intensive efforts are made to prepare carbon fiber reinforced plastics from renewable sources, less emphasis is directed towards elaborating green approaches for carbon fiber surface modification to improve the interfacial adhesion in these composites. In this study, we covalently attach lignin, a renewable feedstock, to a graphitic surface for the first time. The covalent bond is established via aromatic anchoring groups with amine functions taking part in a nucleophilic displacement reaction with a tosylated lignin derivative. The successful grafting procedures were confirmed by cyclic voltammetry, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Both fragmentation and microdroplet tests were conducted to evaluate the interfacial shear strength of lignin coated carbon fiber samples embedded in a green cellulose propionate matrix and in a commercially used epoxy resin. The microdroplet test showed ~27% and ~65% increases in interfacial shear strength for the epoxy and cellulose propionate matrix, respectively. For the epoxy matrix covalent bond, it is expected to form with lignin, while for the cellulosic matrix hydrogen bond formation might take place; furthermore, plastisizing effects are also considered. Our study opens the gates for utilizing lignin coating to improve the shear tolerance of innovative composites.

Three components of plant cell walls—cellulose, hemicellulose and lignin—were converted into flame-retardant thermoplastics by adducting only a single ionic liquid species via covalent bonds. They showed thermoplasticity and formed thin films by hot pressing. They also showed flame retardancy and self-extinguished the fire during burning. The properties of the samples depend on the cation species of ionic liquids adducted and thus are controllable. In the present study, more than 66% of the hydroxyl groups present on the polymers were maintained after derivatisation; they thus have the potential for further functionalisation for moulding, practical use and so on, in addition to flame retardancy and thermoplasticity.