Macroscopic Property Evaluation of Titania Nanocomposite Polymer Capable of Drawing Double-Network Macrostructure Using Photolithography.

In this study, we developed a double-network hybrid polymer that controls the strength and density of cross-linking points by utilizing the bonds of titania and catechol groups with an o-nitrobenzyl group (ONBg) as the photoreactive cross-linking points. In addition, this hybrid material system, which is composed of thermally dissociable bonds between titania and carboxyl groups, can be molded before light irradiation. The Young's modulus increased by approximately 1000 times upon irradiation with UV light. Moreover, introducing microstructures using the photolithography technique improved the tensile strength and fracture energy by approximately 32 and 15 times, respectively, compared to the sample without the photoreaction. The improved toughness was achieved by the macrostructures, which enhanced the effective cleavage of sacrificial bonds between the carboxyl groups and titania.

Skillful Control of Dispersion and 3D Network Structures: Advances in Functional Organic-Inorganic Nano-Hybrid Materials Prepared Using the Sol-Gel Method.

Organic-inorganic hybrid materials have become indispensable high-performance and highly functional materials. This is owing to the improved dispersion control in hybrid materials and emergence of functional ionic liquids. Harmonization of both these factors has enabled the utilization of functional 3D network structures and nanodispersions in composite materials. Polymeric materials endow materials with flexibility, toughness, and shape-memory properties, whereas inorganic materials provide materials with unique optical, electrical, and magnetic properties due to their nanosize. Organic-inorganic hybrid materials have evolved into novel materials that go beyond the composite rule. In this review, the historical development of hybrid materials prepared using the sol-gel method and the birth of ionic liquids have been summarized. In addition, the historical results leading to the development of functional 3D network structures and dispersion control have also been presented, as well as a review of the research on functional ionic liquids, which are of current interest. The authors also summarize the results of their research on functional ionic liquids. The design of new organic-inorganic hybrid materials has been discussed and the future prospects of new polymer composite materials provided.

Rapid removal of detergent in glycolipids using ionic liquids.

Detergent removal in glycolipid after sample preparation, such as enzymatic reaction or isolation of detergent-resistant membrane microdomain, is indispensable for further structural characterization. We previously established the rapid and effective method of detergent removal in glycolipid samples from glass test tube using 1,2-dichloroethane (DCE) washing. However, the use of DCE has several drawbacks, such as environmental risks, harmful effects (potentially carcinogenic), and high vaporability and flammability. To solve the issue, we used ionic liquids to remove detergents from glycolipid samples, and found 1-butyl-3-methylimidazolium iodide was a suitable alternative for DCE.

Dutomycin Induces Autophagy and Apoptosis by Targeting the Serine Protease Inhibitor SERPINB6.

Autophagy plays an important role in maintaining tumor cell progression and survival in response to metabolic stress. Thus, the regulation of autophagy can be used as a strategy for anticancer therapy. Here, we report dutomycin (DTM) as a novel autophagy enhancer that eventually induces apoptosis due to excessive autophagy. Also, human serine protease inhibitor B6 (SERPINB6) was identified as a target protein of DTM, and its novel function which is involved in autophagy was studied for the first time. We show that DTM directly binds SERPINB6 and then activates intracellular serine proteases, resulting in autophagy induction. Inhibitory effects of DTM on the function of SERPINB6 were confirmed through enzyme- and cell-based approaches, and SERPINB6 was validated as a target protein using siRNA-mediated knockdown and an overexpression test. In a zebrafish xenograft model, DTM showed a significant decrease in tumor area. Furthermore, the present findings will be expected to contribute to the expansion of novel basic knowledge about the correlation of cancer and autophagy by promoting active further research on SERPINB6, which was not previously considered the subject of cancer biology.

Polycarbonate/Titania Hybrid Films with Localized Photo-Induced Magnetic-Phase Transition.

Materials that exhibit the photo-induced magnetic-phase transition of titania are receiving significant attention because they can be easily switched between diamagnetism and paramagnetism by UV irradiation. However, it is difficult to store photo-induced titanium (Ti3+) in air because of its easy oxidation upon oxygen exposure. In this study, titania/polycarbonate hybrid films were prepared using linear 1,6-hexanediol (PHMCD), cyclic 1,4-cyclohexanedimethanol (PCHCD), or their copolymerized carbonate oligomers using the sol-gel method. The oxygen permeability of the hybrid film decreased as the ratio of the ring structure increased by a factor of approximately 32 from PHMCD with only the chain structure to PCHCD with only the ring structure. These hybrid films can generate Ti3+ under a UV irradiation of 250 W for 2 h, and the difference in oxygen permeability significantly affected the lifetime of the Ti3+ by a factor of up to 120. In addition, the tensile tests and IR measurements demonstrated that UV irradiation had little effect on the mechanical intensity and matrix chemical structure. Moreover, the magnetic susceptibility of Ti3+ present in PCHCD was confirmed to be 6.2 (10-3 emu/g(titania)) under an external magnetic field of 5 T induced using a superconducting quantum interference device.

One-pot synthesis of monodisperse CoFe2O4@Ag core-shell nanoparticles and their characterization.

In recent years, monodispersed magnetic nanoparticles with a core/shell structure are expected for their wide applications including magnetic fluid, recoverable catalysts, and biological analysis. However, their synthesis method needs numerous processes such as solvent substitution, exchange of protective agents, and centrifugation. A simple and rapid method for the synthesis of monodispersed core-shell nanoparticles makes it possible to accelerate their further applications. This paper describes a simple and rapid one-pot synthesis of core (CoFe2O4)-shell (Ag) nanoparticles with high monodispersity. The synthesized nanoparticles showed plasmonic light absorption owing to the Ag shell. Moreover, the magnetic property of the nanoparticles had a soft magnetic behavior at room temperature and a hard magnetic behavior at 5 K. In addition, the nanoparticles showed high monodispersity with a low polydispersity index (PDI) value of 0.083 in hexane.

Preparation of Crystallites for Oriented Poly(Lactic Acid) Films Using a Casting Method under a Magnetic Field.

Poly-l-lactic acid (PLLA) has biocompatibility and unique characteristics such as piezoelectric properties. This attracts attention not only in the environmental field but also in the biomedical and electronic materials fields. In recent years, the literature about orienting PLLA crystals has been promoting new applications for PLLA such as high strength fiberization and piezoelectric properties. This paper presents a new technique to orient the PLLA crystalline through casting under magnetic irradiation. The advantage of this technique is that it is possible to radiate the magnetic field to the PLLA crystalline in an extremely low viscosity environment. Moreover, the heat treatment condition was optimized in order to improve the low crystallinity of casting, and it succeeded in producing a PLLA film with a high degree of orientation and high crystallinity. Furthermore, PLLA/1-butyl-3-methylimidazolium dibutylphosphate (bmimjdbp) composite films were prepared under the same conditions, and this also succeeded in the further improvement of crystallinity.

Ribosome display and photo-cross-linking techniques for in vitro identification of target proteins of bioactive small molecules.

The identification of target proteins of bioactive small molecules as bioprobe candidates or drug seeds is indispensable for elucidating their actions and predicting their side effects. To meet the current need, we developed a scheme for detection and identification of target proteins by using ribosome display and photo-cross-linking techniques, and demonstrated the feasibility. The mRNAs encoding full-length human proteins (FHPs) were constructed and translated in vitro to prepare pools of FHP-ribosome-mRNA complexes used for ribosome display selection. Expression levels of the FHPs were confirmed by Western blot analysis, and photo-cross-linked small-molecule beads were assessed through cell-free synthesized FHP binding assay. After ribosome display selection against photo-cross-linked small-molecule beads, RT-PCR using mRNAs recovered from the selected ternary complexes and electrophoresis of the PCR products allowed specific detection of the target proteins binding to the beads. In addition, a repeat of ribosome display selection enabled us to identify the target proteins even if the molar quantity was one ten-thousandth of that of the other proteins in a cell-free synthesized FHP pool. Therefore, these results showed that ribosome display using photo-cross-linked small-molecule beads and further extended FHP pool could be one of the powerful techniques for identification of unknown target proteins of bioactive small molecules.

Stabilized ribosome display for in vitro selection.

Ribosome display is a very effective and powerful technology for screening functional peptides or polypeptides in vitro. In ribosome display, each peptide or polypeptide (phenotype) links with its corresponding mRNA (genotype) through a ribosome. This link can be achieved by the absence of a stop codon in the mRNA, therefore stalling the ribosome at the end of translation with the nascent random sequence peptide extended by a spacer outside of the ribosome tunnel. In this chapter, we describe a method for the use of a further stabilized peptide-ribosome-mRNA complex for ribosome display.

Polypeptide aptamer selection using a stabilized ribosome display.

A newly developed ribosome display protocol was applied to the in vitro selection of polypeptide aptamers to small molecular weight chemicals, 6-[hydroxy(4-nitrobenzyl)phosphonyl]hexanoic acid and vitamin B12, chosen from a peptide library of random sequences. New peptide sequences binding to the targets were found after six rounds of this protocol.