Publications by authors named "Mutsumi Yoshida"

Affinity maturation increases antigen-binding affinity and specificity of antibodies by somatic hypermutation. Various monoclonal antibodies against (4-hydroxy-3-nitrophenyl)acetyl (NP) were obtained during affinity maturation. Among them, highly matured anti-NP antibodies, such as E11 and E3, possess Cys96 and Cys100 in the complementarity-determining region 3 of the heavy chain, which would form a disulfide bond.

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Along with traditional attributes such as the size, shape, and chemical structure of polymeric micro-objects, control over material distribution, or selective compartmentalization, appears to be increasingly important for maximizing the functionality and efficacy of biomaterials. The fabrication of tri- and tetracompartmental colloids made from biodegradable poly(lactide-co-glycolide) polymers via electrohydrodynamic co-jetting is demonstrated. The presence of three compartments is confirmed via flow cytometry.

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Biocompatible anisotropic polymer particles with bipolar affinity towards human endothelial cells are a novel type of building blocks for microstructured bio-hybrid materials. Functional polarity due to two biologically distinct hemispheres has been achieved by synthesis of anisotropic particles via electro-hydrodynamic co-jetting of two different polymer solutions and subsequent selective surface modification.

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Biocompatible anisotropic polymer particles with bipolar affinity towards human endothelial cells are a novel type of building blocks for microstructured biohybrid materials, report Joerg Lahann and co-workers on p. 4920. Functional polarity due to two biologically distinct hemispheres has been achieved by synthesis of anisotropic particles via electro-hydrodynamic co-jetting of two different polymer solutions and subsequent selective surface modification.

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Biodegradable, compositionally anisotropic microparticles with two distinct compartments that exhibit controlled shapes and sizes are fabricated. These multifunctional particles are prepared by electrohydrodynamic co-jetting of poly(lactide-co-glycolide) polymer solutions. By varying different solution and process parameters, namely, concentration and flow rate, a variety of non-equilibrium bicompartmental shapes, such as discoid and rod-shaped microparticles are produced in high yields.

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"Smart" materialsmaterials that respond to a stimulus or their environment to produce a dynamic and reversible change in critical propertieshave enabled progress in many areas, including display technologies, drug delivery, and self-healing materials for coating applications, among others. Many of the current examples of smart materials are biomimetic, since nature employs and depends on dynamic and rapid switching for critical functions such as vision, camouflage, and ion channel regulation. Despite progress in designing smart materials and surfaces, much work is still needed in this area to increase their implementation in useful applications.

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Electrified co-jetting of two aqueous polymer solutions followed by a thermal cross-linking step was used to create water-stable biphasic nanocolloids. For this purpose, aqueous solution mixtures of poly(acrylamide-co-acrylic acid) and poly(acrylic acid) were employed as jetting solutions. When the biphasic nanocolloids created by side-by-side electrified co-jetting were thermally treated, a cross-linking reaction occurred between amide groups and carboxylic groups to form stable imide groups.

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Advances in nanotechnology, in particular the development of novel types of nanoparticles, will result in advanced tools for biomedical research and clinical practice. One exciting aspect of future nanomaterial research will be the possibility to combine therapy and imaging in multifunctional nanoparticle designs. In this context, anisotropic particles with subcellular dimensions may offer so far unattainable capabilities, because they could provide access to directional information with respect to nanoparticle-cell interactions.

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The ability of immature dendritic cells (iDCs) derived from human peripheral blood mononuclear cells to phagocytose poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) as compared to polystyrene MPs and the molecular aspects of this phagocytosis were investigated. Treating iDCs with PLGA or polystyrene fluorospheres of approximately 3 microm in diameter resulted in the internalization of the particles as evidenced by confocal laser scanning micrographs. This uptake of fluorospheres by DCs was decreased by pretreatment of cells with cytochalasin D or by incubation with the fluorospheres at 4 degrees C, and was sensitive to EDTA and trypsin pretreatments in a dose-dependent manner.

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Understanding of biomaterial adjuvant effect and its mechanisms is essential for the effective design and selection of appropriate materials for specific applications. We have previously shown that poly(lactic-co-glycolic acid) (PLGA), one of the most commonly studied polymers in tissue engineering, supports an adjuvant effect as measured by enhanced immune response against a co-delivered model antigen, which was dependent on the form of the biomaterial. Furthermore, we have shown that PLGA induces the maturation of human peripheral blood mononuclear cell-derived dendritic cells (DCs) in vitro.

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Application of biomaterials in combination products in which the biomaterial is presented to the host with a biological component prompts the need for understanding the biomaterial-associated adjuvant effect in the immune response against antigens associated with such a product. We have previously demonstrated that a polymer commonly used in tissue engineering and vaccine delivery, poly(lactic-co-glycolic acid) (PLGA), exerts an adjuvant effect in vivo, which was supported by PLGA-induced dendritic cell (DC) maturation in vitro. In this study, the effects of agarose and PLGA on DC maturation were compared in vitro to establish differential biomaterial effects.

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Immature dendritic cells (iDCs) were derived from human peripheral blood monocytes, and treated with 75:25 poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) or film to assess the resultant dendritic cell (DC) maturation as compared to positive control of lipopolysaccharide (LPS) treatment for DC maturation or negative control of untreated iDCs. The effect of PLGA contact on DC maturation was examined as one possible explanation for the PLGA adjuvant effect we have observed in the enhancement of an immune response to codelivered model antigen, as adjuvants act through the maturation of DCs. Culturing iDCs with PLGA MPs or PLGA film resulted in morphology similar to that of LPS-matured DCs and the association, or possible internalization, of PLGA MPs.

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Ranges in diurnal variation and the patterns of body temperature (T), blood pressure (BP), heart rate (HR) and locomotor activity (LA) in 61 laboratory beagle dogs were analyzed using a telemetry system. Body temperature, BP, HR and LA increased remarkably at feeding time. Locomotor activity increased sporadically during the other periods.

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