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Takeshi Serizawa - One of the best experts on this subject based on the ideXlab platform.

  • Affinity-based thermoresponsive fluorescence switching of proteins conjugated with a Polymer-Binding peptide.
    Soft matter, 2020
    Co-Authors: Toshiki Sawada, Seigo Suzuki, Takeshi Serizawa
    Abstract:

    The affinity-based thermoresponsive fluorescence switching of proteins conjugated with a Polymer-Binding peptide is demonstrated. The specific affinity of the peptide and thermoresponsive structural transitions of the Polymer are essential for reliable fluorescence switching behavior.

  • Preparation of Biocomposite Soft Nanoparticles Composed of Poly(Propylene Oxide) and the Polymer-Binding Peptides
    Processes, 2020
    Co-Authors: Toshiki Sawada, Hiroki Fukuta, Takeshi Serizawa
    Abstract:

    The molecular recognition capability of naturally occurring biomolecules is generally expressed against biomolecules in the biological milieu. Recently, it was demonstrated that the specific interactions of biomolecules such as short peptides were applicable to artificial materials. We have developed peptides with specific affinities for synthetic Polymers toward functional biocomposite Polymeric materials. In this study, we demonstrated the preparation of biocomposite nanoparticles composed of poly(propylene oxide) (PPO) and PPO-Binding peptides. A simple injection of a concentrated PPO solution dissolved in an organic solvent into the peptide solution under sonication resulted in the formation of nanospherical structures. Morphological observation indicated characteristic softness and high applicability as a molecular carrier of the biocomposite nanoparticles. Structural characterization of PPO and the PPO-Binding peptide revealed the structural conformability of these molecules to interact specifically with each other. Our findings expand the potential applicability of Polymer-Binding peptides for the future construction of biomedical materials composed of peptides and various Polymers.

  • Preparation and Dynamic Behavior of Protein-Polymer Complexes Formed with Polymer-Binding Peptides
    Bulletin of the Chemical Society of Japan, 2020
    Co-Authors: Samyukta Ravishankar, Toshiki Sawada, Seigo Suzuki, Sierin Lim, Takeshi Serizawa
    Abstract:

    The development of protein-Polymer complexes using protein cages is garnering attention as a strategy to overcome challenges that relate to immunogenicity and protease degradation. We propose the u...

  • Affinity-Based Functionalization of Biomedically UtilizedMicelles Composed of Triblock CoPolymers through Polymer-Binding Peptides
    ACS biomaterials science & engineering, 2019
    Co-Authors: Toshiki Sawada, Misaki Takizawa, Takeshi Serizawa
    Abstract:

    Polymeric micelles and vesicles that are self-assembled from amphiphilic block coPolymers are frequently used in biomedical applications. Poly(ethylene oxide) (PEO)–poly(propylene oxide) (PPO)–PEO, so-called Pluronic, is a Food and Drug Administration approved triblock coPolymer utilized in biomedical applications. However, the control of drug loading and surface functionalization of micelles remain challenging due to structural limitations. In this study, Pluronic micelles with various structures were rationally functionalized via the PPO-Binding peptide, which was previously identified using a biologically constructed peptide library displayed on filamentous phages. The interactions between the peptide and Pluronic micelles were characterized in detail based on fluorescence changes in an extrinsic fluorescence dye, and a sufficient PPO chain length of Pluronic was essential for the interactions. Furthermore, enzymatic degradation of the model substrate-conjugated peptide loaded into Pluronic micelles sh...

  • Affinity-based thermoresponsive precipitation of proteins modified with Polymer-Binding peptides
    Chemical communications (Cambridge England), 2016
    Co-Authors: Seigo Suzuki, Toshiki Sawada, Takashi Ishizone, Takeshi Serizawa
    Abstract:

    A 12-mer peptide with an affinity for the meso diad sequence of poly(N-isopropylacrylamide) (PNIPAM) was identified through affinity-based peptide screening. A model protein (i.e., human serum albumin (HSA)) chemically modified with the peptide was successfully precipitated with PNIPAM above the lower critical solution temperature (LCST) of PNIPAM.

Toshiki Sawada - One of the best experts on this subject based on the ideXlab platform.

  • Affinity-based thermoresponsive fluorescence switching of proteins conjugated with a Polymer-Binding peptide.
    Soft matter, 2020
    Co-Authors: Toshiki Sawada, Seigo Suzuki, Takeshi Serizawa
    Abstract:

    The affinity-based thermoresponsive fluorescence switching of proteins conjugated with a Polymer-Binding peptide is demonstrated. The specific affinity of the peptide and thermoresponsive structural transitions of the Polymer are essential for reliable fluorescence switching behavior.

  • Preparation of Biocomposite Soft Nanoparticles Composed of Poly(Propylene Oxide) and the Polymer-Binding Peptides
    Processes, 2020
    Co-Authors: Toshiki Sawada, Hiroki Fukuta, Takeshi Serizawa
    Abstract:

    The molecular recognition capability of naturally occurring biomolecules is generally expressed against biomolecules in the biological milieu. Recently, it was demonstrated that the specific interactions of biomolecules such as short peptides were applicable to artificial materials. We have developed peptides with specific affinities for synthetic Polymers toward functional biocomposite Polymeric materials. In this study, we demonstrated the preparation of biocomposite nanoparticles composed of poly(propylene oxide) (PPO) and PPO-Binding peptides. A simple injection of a concentrated PPO solution dissolved in an organic solvent into the peptide solution under sonication resulted in the formation of nanospherical structures. Morphological observation indicated characteristic softness and high applicability as a molecular carrier of the biocomposite nanoparticles. Structural characterization of PPO and the PPO-Binding peptide revealed the structural conformability of these molecules to interact specifically with each other. Our findings expand the potential applicability of Polymer-Binding peptides for the future construction of biomedical materials composed of peptides and various Polymers.

  • Preparation and Dynamic Behavior of Protein-Polymer Complexes Formed with Polymer-Binding Peptides
    Bulletin of the Chemical Society of Japan, 2020
    Co-Authors: Samyukta Ravishankar, Toshiki Sawada, Seigo Suzuki, Sierin Lim, Takeshi Serizawa
    Abstract:

    The development of protein-Polymer complexes using protein cages is garnering attention as a strategy to overcome challenges that relate to immunogenicity and protease degradation. We propose the u...

  • Affinity-Based Functionalization of Biomedically UtilizedMicelles Composed of Triblock CoPolymers through Polymer-Binding Peptides
    ACS biomaterials science & engineering, 2019
    Co-Authors: Toshiki Sawada, Misaki Takizawa, Takeshi Serizawa
    Abstract:

    Polymeric micelles and vesicles that are self-assembled from amphiphilic block coPolymers are frequently used in biomedical applications. Poly(ethylene oxide) (PEO)–poly(propylene oxide) (PPO)–PEO, so-called Pluronic, is a Food and Drug Administration approved triblock coPolymer utilized in biomedical applications. However, the control of drug loading and surface functionalization of micelles remain challenging due to structural limitations. In this study, Pluronic micelles with various structures were rationally functionalized via the PPO-Binding peptide, which was previously identified using a biologically constructed peptide library displayed on filamentous phages. The interactions between the peptide and Pluronic micelles were characterized in detail based on fluorescence changes in an extrinsic fluorescence dye, and a sufficient PPO chain length of Pluronic was essential for the interactions. Furthermore, enzymatic degradation of the model substrate-conjugated peptide loaded into Pluronic micelles sh...

  • Affinity-based thermoresponsive precipitation of proteins modified with Polymer-Binding peptides
    Chemical communications (Cambridge England), 2016
    Co-Authors: Seigo Suzuki, Toshiki Sawada, Takashi Ishizone, Takeshi Serizawa
    Abstract:

    A 12-mer peptide with an affinity for the meso diad sequence of poly(N-isopropylacrylamide) (PNIPAM) was identified through affinity-based peptide screening. A model protein (i.e., human serum albumin (HSA)) chemically modified with the peptide was successfully precipitated with PNIPAM above the lower critical solution temperature (LCST) of PNIPAM.

A Slocombe - One of the best experts on this subject based on the ideXlab platform.

  • The effect of pigment addition in diode laser ablation machining of ceramic/Polymer composite material
    Applied Surface Science, 2000
    Co-Authors: A Slocombe, J Clarke
    Abstract:

    This paper reports on the laser machining of ceramic materials by the ablation of a low temperature pigmented Polymer Binding material. Through initial compacting and infiltration of various blends of ceramic powder with a low temperature Polymer Binding material (with added pigments) it is possible to ablate the composite material with much reduced energy requirement compared to that for solid ceramic blocks. It was found that out of three different black pigments tested (graphite plasticiser, ink and powder paint) the powder paint proved to be the best form of pigmentation to be added to the composite mixture in order to achieve increased laser beam absorptivity and machinability. The variation of laser beam absorptivity with the amount of pigment was established. It was found that the laser beam absorption could be increased from 12% without any pigment to over 90% with just over 1% pigment.

  • Laser ablation machining of metal/Polymer composite materials
    Applied Surface Science, 2000
    Co-Authors: A Slocombe
    Abstract:

    This paper reports on the laser machining of metallic materials by the ablation of a low temperature Polymer Binding material. Through initial compacting and infiltration of various blends of metal powders with a low temperature Polymer Binding material, it is possible to laser machine high surface quality three-dimensional parts. The machining mechanism has been found to be one of absorption of the laser beam by the metal powders and heat conduction transfer to the Polymer causing instant vaporisation of the Polymer which breaks the bonds between metal powders and, with the help of an inert gas jet, in turn ejects the metal powder.

  • Diode laser ablation machining of 316L stainless steel powder/Polymer composite material: Effect of powder geometry
    Applied Surface Science, 2000
    Co-Authors: A Slocombe, A. Taufik
    Abstract:

    This paper reports on the laser machining of 316L stainless steel by the ablation of a low temperature Polymer Binding material. This investigation compares the effect of powder geometry on laser machinabilty. It was found that only spherical powders can be effectively removed using this technique, whilst irregular powders formed mechanical interlock due to compaction which hindered the material removal, hence the formation of doss.

  • Feasibility and effects of producing high temperature/strength superalloyed solid parts through diode laser machining of metal/Polymer composite material
    International Congress on Applications of Lasers & Electro-Optics, 1999
    Co-Authors: A Slocombe
    Abstract:

    This paper reports on the laser machining of high temperature/strength superalloyed NiCr solid parts by the ablation of a low temperature Polymer Binding material using a 60W diode laser with coaxal gas jet. Through initial compacting and infiltration of nickel alloy powders with a low temperature Polymer Binding material it is possible to laser machine high surface quality grooves. A thermoset Polymer rather than a thermoplast Polymer is required for the matrix material. The machining mechanism has been found to be one of absorption of the laser beam by the nickel alloy powders and heat conduction transfer to the Polymer causing instant vaporization of the Polymer which breaks the bonds between metal powders and with the help of an inert gas jet, the metal powders are ejected.

Yu Chi Wang - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of molecular imprinted organic–inorganic hybrid Polymer Binding caffeine
    Analytica Chimica Acta, 2003
    Co-Authors: Abraham K Joseph, Chao Kang Chang, Yu Chi Wang
    Abstract:

    Abstract Random coPolymers of poly{(methacrylamide)-co-(vinyl trimethoxysilane)} and poly{(methacrylic acid)-co-(vinyl trimethoxysilane)} were synthesized via a free radical Polymerization reaction. Acid catalyzed sol–gel process of tetraethylorthosilicate (TEOS) with aforementioned Polymers in the presence of methyl xanthine class of alkaloid like caffeine resulted in the formation of highly transparent monoliths. Solvent extraction of the template leaves behind the recognition sites intact with high selectivity towards the print molecule. The ionic and non-specific adsorptions, which are considered to be the main disadvantages of the molecularly imprinted Polymers (MIP), are prevented to a considerable extent by the end capping of surface silanol groups. The template Binding efficiencies of MIP were determined by HPLC analysis.

Paola Fiorani - One of the best experts on this subject based on the ideXlab platform.

  • Mutations of human DNA topoisomerase I at poly (ADP-ribose) Binding sites: modulation of camptothecin activity by ADP-ribose Polymers
    Journal of experimental & clinical cancer research : CR, 2014
    Co-Authors: Cinzia Tesauro, Grazia Graziani, Barbara Arnò, Laura Zuccaro, Alessia Muzi, Ilda D'annessa, Elettra Santori, Lucio Tentori, Carlo Leonetti, Paola Fiorani
    Abstract:

    Background: DNA topoisomerases are key enzymes that modulate the topological state of DNA through the breaking and rejoining of DNA strands. Human topoisomerase I belongs to the family of poly(ADP-ribose)-Binding proteins and is the target of camptothecin derived anticancer drugs. Poly(ADP-ribosyl)ation occurs at specific sites of the enzyme inhibiting the cleavage and enhancing the religation steps during the catalytic cycle. Thus, ADP-ribose Polymers antagonize the activity of topoisomerase I poisons, whereas PARP inhibitors increase their antitumor effects. Methods: Using site-directed mutagenesis we have analyzed the interaction of human topoisomerase I and poly (ADP-ribose) through enzymatic activity and Binding procedures. Results: Mutations of the human topoisomerase I hydrophobic or charged residues, located on the putative Polymer Binding sites, are not sufficient to abolish or reduce the Binding of the poly(ADP-ribose) to the protein. These results suggest either the presence of additional Binding sites or that the mutations are not enough perturbative to destroy the poly(ADP-ribose) interaction, although in one mutant they fully abolish the enzyme activity. Conclusions: It can be concluded that mutations at the hydrophobic or charged residues of the putative Polymer Binding sites do not interfere with the ability of poly(ADP-ribose) to antagonize the antitumor activity of topoisomerase I poisons.