Noritada Kaji

Nagoya University, Nagoya, Aichi, Japan

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Publications (183)581.42 Total impact

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    ABSTRACT: A novel nanopillar chip, which combines pillar structures (nanopillars) and dammed structures (nanoslits) at the nanometer scale inside a microchannel, was fabricated and applied to micro-RNA isolation from a mixture of nucleic acids. Electrophoretic behaviors of micro-RNA and DNA fragments in the nanopillar chip were carefully investigated and the isolation condition was optimized for the mixture of 10-kbp, lambda (48.5-kbp) and T4 DNA (165.5-kbp).
    No preview · Conference Paper · Oct 2013
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    ABSTRACT: To precisely quantitate the effect of chemoattractants on directional pollen tube growth, a new microdevice was developed. Torenia fournieri pollen tubes, which generally grow freely on agarose medium, were funneled through a narrow flow channel that splits into a T-shaped channel leading to two reservoirs. The main channel was thus divided in two so that pollen tubes could choose their growth in either the left or right direction. Liquid solution or plant tissues were loaded into the reservoir, and diffusible molecules from the materials gradually spread in the narrow channel, leading to a concentration gradient. When egg-cell containing ovules were placed in one reservoir, pollen tubes grew selectively in that direction, suggesting that materials secreted from the ovules attracted the pollen tubes. Furthermore, UV-irradiation of female gametophytes in ovules decreased their ability to attract pollen tube growth. These results suggest that this novel device provides a unique platform for screening materials that may attract pollen tubes and for quantitatively analyzing the chemical features of attractants.
    No preview · Article · Oct 2013 · RSC Advances
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    ABSTRACT: Technologies for the transfection of antigen-encoding genes into the dendritic cells, and subsequent immune-activation are both prerequisites for a successful DNA vaccine. We herein report on the density-dependent enhancement of transgene expression by the simple modification by stearyl-conjugated KALA, an α-helical peptide (STR-KALA), onto a lipid envelope-type nanoparticle (the R8-MEND, an octaarginine-modified multifunctional envelope-type nano device). The enhanced transgene expression in the KALA-modified R8-MEND (R8/KALA-MEND) cannot be explained by cellular uptake and nuclear delivery efficacy. Thus, the post-nuclear delivery process (i.e. transcription), but not intracellular trafficking processes attributed the enhanced transfection efficacy. Microarray analyses revealed that transfection with the R8/KALA-MEND resulted in a greater perturbation in host genes expression in comparison with the R8-MEND and that this effect was time-dependent. Further pathway analyses in the category of transcription-related genes and a gene ontology analysis indicated that the R8/KALA-MEND stimulated the expression of transcription factors that are closely related to immune-activation (i.e. NF-kB and STAT). Inhibition of the transfection efficacy by blockage of the STAT pathways revealed that the enhanced transcription activity is the result of immune-stimulation. Collectively, the R8/KALA-MEND mounts a "switch-on" function that triggers signal transduction forward to the immune-stimulation analogous to an adjuvant, and consequently elicits active transcription.
    No preview · Article · Aug 2013 · Biomaterials
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    ABSTRACT: We reported an optical DNA/protein microfluidic sensor which consists of single stranded (ss) DNA-Cy3 probes on gold surface and simple line-shape microfluidic channel. These ssDNA-Cy3 probes with random sequence in bulk solution or on gold surface exhibits fluorescence enhancement after binding with complementary ssDNA (cssDNA) targets. Particularly it did not require complicated design or hairpin-like stem-loop conformation, which made it easier to be made and applied in analytes detection by fluorescence switching techniques. Using ssDNA-cy3 probes attached on gold surface in a microfluidic channel, strong fluorescence enhancement was measured by ssDNA with cssDNA binding or ssDNA with cssDNA-biotin binding. The following introduction of streptavidin resulted in fluorescence quenching (fluorescence decrease) because of the binding of hybridized DNA-biotin with streptavidin. This sensor showed strong affinity and high sensitivity toward the streptavidin, the minimum detectable concentration for streptavidin was 1pM, equating to an absolute detection limit of 60amol in this microfluidic channel. Microfluidic channel height and flow rate is optimized to increase surface reaction efficiency and fluorescence switching efficiency. In contrast to previously reported optical molecular beacon approach, this sensor can be used not only for the detection of cssDNA target, but also for the detection of streptavidin. This microfluidic sensor offers the promise of analyzing kinds of molecular targets or immunoreactions.
    Full-text · Article · Aug 2013 · Biosensors & Bioelectronics

  • No preview · Article · Jun 2013 · International Journal of Antimicrobial Agents
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    ABSTRACT: For years, nanotechnology has shown great promise in the fields of biomedical and biotechnological sciences and medical research. In this review, we demonstrate its versatility and applicability in plant cell biology studies. Specifically, we discuss the ability of functionalized carbon nanotubes to penetrate the plant cell wall, target specific organelles, probe protein-carrier activity and induce organelle recycling in plant cells. We also, shed light on prospective applications of carbon nanomaterials in cell biology and plant cell transformation.
    No preview · Article · Mar 2013 · RSC Advances
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    ABSTRACT: Electrokinetic manipulations of biomolecules using artificial nanostructures within microchannels have proven capability for controlling the dynamics of biomolecules. Since there is an inherent spatial size limitation to lithographic technology, especially for nanostructures with a small diameter and high aspect ratio, manipulating a single small biomolecule such as in DNA elongation before nanopore sequencing is still troublesome. Here we show the feasibility for self-assembly of a nanowire array embedded in a microchannel on fused silica substrate as a means to manipulate the dynamics of a single long T4-DNA molecule and also separate DNA molecules. High-resolution optical microscopy measurements are used to clarify the presence of fully elongated T4-DNA molecules in the nanowire array. The spatial controllability of sub-lithographic scale nanowires within microchannels offers a flexible platform not only for manipulating and separating long DNA molecules, but also for integrating with other nanostructures to detect biomolecules in such methods as nanopore sequencing.
    Full-text · Article · Mar 2013 · ACS Nano
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    ABSTRACT: A microchip-based real-time polymerase chain reaction (PCR) device has been developed for the genetic tug-of-war (gTOW) method that provides quantitative data for research on biorobustness and systems biology. The device was constructed of a silicon glass chip, a temperature controlling Peltier element, and a microscope. A parallel real-time amplification process of target genes on the plasmids and the housekeeping genes in a model eukaryote Saccharomyces cerevisiae were detected simultaneously, and the copy number of the target genes were estimated. The device provides unique quantitative data that can be used to augment understanding of the system-level properties of living cells.
    No preview · Article · Mar 2013 · Analytical Sciences
  • Takao Yasui · Noritada Kaji · Yoshinobu Baba
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    ABSTRACT: Nanobiodevices have been developed to analyze biomolecules and cells for biomedical applications. In this review, we discuss several nanobiodevices used for disease-diagnostic devices, molecular imaging devices, regenerative medicine, and drug-delivery systems and describe the numerous advantages of nanobiodevices, especially in biological, medical, and clinical applications. This review also outlines the fabrication technologies for nanostructures and nanomaterials, including top-down nanofabrication and bottom-up molecular self-assembly approaches. We describe nanopillar arrays and nanowall arrays for the ultrafast separation of DNA or protein molecules and nanoball materials for the fast separation of a wide range of DNA molecules, and we present examples of applications of functionalized carbon nanotubes to obtain information about subcellular localization on the basis of mobility differences between free fluorophores and fluorophore-labeled carbon nanotubes. Finally, we discuss applications of newly synthesized quantum dots to the screening of small interfering RNA, highly sensitive detection of diseaserelated proteins, and development of cancer therapeutics and diagnostics. Expected final online publication date for the Annual Review of Analytical Chemistry Volume 6 is June 15, 2013. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
    No preview · Article · Mar 2013 · Annual Review of Analytical Chemistry (2008)
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    ABSTRACT: The technical development of long-term fluorescent observation of single DNA molecules is central to fields ranging from molecular biological detection to understanding the physical properties of them under a microscope. Here, we address this challenge using protocatechuic acid and protocatechuate-3,4-dioxygenase (PADase) and demonstrate fluorescent lifetimes of dyed single DNA molecules of 150–180 s, three times longer than those without any treatments.
    No preview · Article · Feb 2013 · RSC Advances
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    ABSTRACT: Staphylococcal enterotoxins (SEs), produced by Staphylococcus aureus, are a major cause of staphylococcal food poisoning. Traditionally, sandwich enzyme-linked immunosorbent assay (ELISA) and reverse passive latex agglutination with rabbit antibody IgG have been used to detect SEs. However, most of these kits require a long processing time and there is a risk of false-positive results since IgG reacts nonspecifically with protein A produced by S. aureus. In this study, we prepared antienterotoxin chicken IgY antibodies specific for each SE (SEA to SEE) without reaction with protein A, which enabled a drastic reduction in nonspecific reactions. ELISAs, lateral flow device (LFDs), and IgY-based immunopillar chips were developed for SE detection. All the ELISAs developed were as sensitive as commercially available kits. The SEs in milk were successfully detected by the ELISAs, LFDs, and immunopillar chips without any sample pretreatment. The LFD could detect SEA even at the low concentration of 0.2ng/ml within 15min in milk. The detection limit of the immunopillar chips for the SEs ranged from 0.01 to 0.1ng/ml in milk; the SEs were detected within 12min and specialized skills were not required. The ELISA and LFD detected SEA in dairy products artificially contaminated with S. aureus, including ice cream, yogurt, and café au lait, in a dose-dependent manner. In conclusion, IgY allows highly specific detection of SEs, and ELISAs, LFDs, and immunopillar chips should be useful tools for screening SEs in milk and dairy products.
    Full-text · Article · Jan 2013 · Journal of microbiological methods
  • D. Onoshima · N. Kaji · M. Tokeshi · Y. Baba
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    ABSTRACT: An intermittent molecular encounter leading to a site-specific DNA-break was unveiled under a limited protein's sliding-free condition. It reflects a transient molecular action by which the reaction rate and efficiency of restriction enzyme in bacterial cells is enhanced. This was experimentally verified for the first time in the world by using our microfluidic device.
    No preview · Article · Jan 2013
  • H. Yasaki · D. Onoshima · T. Yasui · T. Naito · N. Kaji · Y. Baba
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    ABSTRACT: We developed a method for making high-density arrayed DNA molecules on PDMS and glass substrates. Arrayed DNA could be applied to various observation methods, and were elongated and immobilized on cover plates without any modification to DNA molecules. The depth, size and shape of the devices were optimized. It enables researchers to make such a high-density array of DNA molecules in a simple way. Copyright © (2013) by the Chemical and Biological Microsystems Society All rights reserved.
    No preview · Article · Jan 2013
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    ABSTRACT: We have developed immunopillar devices for rapid and easy-to-use immunoassay with pM-fM detection sensitivity, but long total assay time (sample-in-answer-out) and the compatibility with a portable detection system have still remained as major problems toward the point-of-care testing (POCT). We report here next generation immunopillar devices and portable detection system suitable for them. Thin structure of those devices allowed us to wash nonspecifically bound antigens and fluorescent-labeled secondary antibodies in a minute, resulting in the dramatic reduction in the total assay time. In addition, by using the portable detection system, we gained the concentrations of C-reactive protein in human sera while preserving pM detection sensitivity. The total assay time was 20 minutes per sample. Our immunoassay system possesses the potential for use in POCT.
    No preview · Conference Paper · Jan 2013
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    ABSTRACT: We could achieve label-free detection and quantification of real-time DNA amplification using a one-dimensional (1D) photonic crystal embedded in microchannels. Our method could be applicable to ultra-highly sensitive detection of human papillomavirus (HPV) and tubercle bacillus (TB) from 1 zmol to 1 amol. The limit of detection (LOD) of TB sequence in our system was around 500 ymol.
    No preview · Article · Jan 2013
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    ABSTRACT: We developed microfluidic continuous purification devices based on free-flow electrophoresis for gene-delivery multifunctional envelope-type nanodevices (MEND) which consists of DNA core and phospholipid bilayer envelope. Various impurities, such as DNA, DNA-peptide complex, and liposomes, produced during the fabrication process were removed in an efficient manner and over 75% collection of the input plasmid DNA which corresponds to purified MEND was achieved.
    No preview · Article · Jan 2013
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    ABSTRACT: We present here a novel microchamber sealing valve that is self-actuated by a pressure change during the temperature change in the thermal activation of reactions. Actuation of our valve requires only the use of the same heating device as employed for the reactions. A thermoplastic UV-curable polymer is used as a device material; the polymer allows realization of the temperature-driven valve actuation as well as the fabrication of multi-layered devices. The self-actuated valve achieves effective sealing of the microchamber for the polymerase chain reaction (PCR) even at 90 °C, which is essential for developing highly parallel PCR array devices without the need for complicated peripherals to control the valve operation.
    Full-text · Article · Dec 2012 · Lab on a Chip
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    ABSTRACT: Magnetic resonance imaging (MRI) using contrast agents has been widely used to diagnose vascular diseases, to visualize the internal structure of organs, and to monitor transplanted cells and tissues. We recently developed a novel contrast agent for MRI using polysaccharide-modified magnetic iron oxide nanoparticles. The polysaccharide-magnetic particle complex has an advantage of low toxicity to cells and tissues and slow blood clearance over conventional contrast agents. However, because the surface charge of the particles is negative, transplanted cells such as pancreatic islet cells are less labeled. To overcome this problem, a complex of a polysaccharide and a positively charged magnetic metallic compound has been developed. These newly designed magnetic nanoparticles were efficiently transduced into various cells (for example pancreatic islet cells, MIN6 cells, HepG2 cells, hepatocytes, and somatic stem cells). The present chapter mainly describes the establishment of a cytotoxicity test system using our polysaccharide-based magnetic iron oxide nanoparticles. As a promising cell evaluation system, a new three-dimensional cell culture system "cell-array system" has been established. In the future, the system will be useful as a powerful tool for drug development.
    No preview · Chapter · Dec 2012
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    ABSTRACT: Dry film resist SU-8 was used to make a thick mold for soft lithography of a poly(dimethylsiloxane) (PDMS) microfluidic chip with deep channels. The stacking of the SU-8 film enabled an ultra-thick (up to 500 μm) resist process on Si wafer. This process was fast and highly reproducible compared with the conventional liquid SU-8 process. The deep channel in the PDMS chip was utilized as a micro-flow cell for sensitive absorbance measurement. Sunset Yellow FCF dye was used to demonstrate absorption spectroscopy in the deep channel. Since the channel depth was proportional to the optical path length, which was proportional to the absorbance value, the PDMS chip achieved a detection limit (15.9 μM) comparable to U- or Z-shaped microfabricated absorbance detection cells in glass. Calibration curves for different solution concentrations were obtained with good R2 values (1).
    No preview · Article · Nov 2012 · Analytical methods
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    ABSTRACT: To date, there is no consensus on the relationship between the physicochemical characteristics of carbon nanotubes (CNTs) and their biological behavior, however, there is growing evidence that the versatile characteristics make their biological fate largely unpredictable and remain an issue of limited knowledge. Here we introduce an experimental methodology for tracking and visualization of post-uptake behavior and the intracellular fate of CNTs based on the spatial distribution of diffusion values throughout the plant cell. By using raster scan image correlation spectroscopy (RICS), we were able to generate highly quantitative spatial maps of CNTs diffusion in different cell compartments. The spatial map of diffusion values revealed that the uptake of CNTs is associated with important subcellular events such as carrier-mediated vacuolar transport and autophagy. These results show that RICS is a useful methodology to elucidate the intracellular behavior mechanisms of carbon nanotubes and potentially other fluorescently labeled nanoparticles, which is of relevance for the important issues related to the environmental impact and health hazards.
    Preview · Article · Nov 2012 · Nano Letters

Publication Stats

2k Citations
581.42 Total Impact Points

Institutions

  • 2007-2015
    • Nagoya University
      • Graduate School of Engineering
      Nagoya, Aichi, Japan
  • 2000-2004
    • The University of Tokushima
      • • Department of Medicinal Biochemistry
      • • Faculty of Pharmaceutical Sciences
      Tokusima, Tokushima, Japan