The toxicity and behavior (internalization, adhesion, dispersion) of manufactured polystyrene latex (PSL) nanoparticles (nominal diameter : 50 nm) with various functional groups toward the yeast Saccharomyces cerevisiae as a model eukaryote were examined using the colony count method and microscopic observation. The colony count tests suggested that the PSL nanoparticles with a negative surface charge had little or no toxicity toward the yeast. In contrast, PSL nanoparticles with an amine functional group and a positive surface charge (p-Amine) displayed a high toxicity in 5 mol/m³ NaCl, whereas the p-Amine were mostly unharmed in 154 mol/m³ NaCl, which was quite different with the toxicological effects of Escherichia coli as a model prokaryote. Confocal and atomic force microscopy indicated that in 5 mol/m³ NaCl the p-Amine nanoparticles entirely covered the surface of the yeast, and cell death occurred, whereas in 154 mol/m³ NaCl were internalized by endocytosis, and cell death did not occur.

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SiO₂@Au core-shell type particles are quite attractive because of their unique optical properties and potential biomedical applications including imaging, sensing, photothermal therapy, and gene-silencing technology. A widely-used preparation technique of Au nanoshells is the seed-mediated growth, which is composed of three steps: surface modification of core silica particles, Au seeds decoration of the modified silica surface and the shell growth by reduction of Au ions on the Au seeds. Although this technique allows good control in the shell thickness, it takes a long time on the order of days to complete the preparation process. In the present study, we develop a flow synthetic process by applying a microreactor separately to the Au seeds decoration and the shell growth processes. In the decoration process, we demonstrate that the microreactor enables one-step fabrication of gold decorated silica particles by directly reducing Au ions with a strong reducing agent (NaBH₄) in the presence of silica particles, which can remarkably shorten the preparation period. The microreactor flow synthesis is also demonstrated to be effective for the shell growth process when a mild reducing agent (NH₂OH·HCl) is used to suppress the nucleation in the solution phase instead of the Au seeds surface.

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This paper presents molecular dynamics (MD) simulations of penetration behavior of gold nanoparticles into a model biological membrane (lipid bilayer). Gold nanoparticles functionalized with alkanethiol ligands having different charge properties and different alkyl chain lengths were used as model particles. Effects of the particle surface properties on the nanoparticle penetration behavior into a lipid bilayer were investigated. The simulation results showed that the neutral and negatively charged gold nanoparticles did not penetrate into the lipid bilayer, while a positively charged gold nanoparticle spontaneously penetrated into the lipid bilayer and highly disrupted original structure of the lipid bilayer. However, positively charged gold nanoparticles modified by longer alkyl chain than that of lipid molecules were internalized into hydrophobic interior of the lipid bilayer without any disruption of the lipid bilayer. The simulation results can provide insight into design of the nanoparticles at molecular level to achieve various bio-applications of the gold nanoparticles.

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The one-step synthesis of ceramic coated magnetic metal nanoparticles is described using a radio-frequency (RF) thermal plasma. Phase compositions of the obtained nanoparticles were characterized by X-ray diffraction and shapes and size of the synthesized particles were analyzed by an electron microscope. Additionally, elements analysis of the coated particles was performed by energy dispersive spectroscopy. The phase composition of the prepared particles was mainly composed of amorphous ceramics and magnetic metal. It was confirmed that the magnetic metal particles was coated by ceramics. Furthermore, the mechanism of the formation of ceramic coated metal in the plasma was predicted. The obtained FeCo-Al₂O₃ core-shell nanoparticles have a magnetic value of 1.96×10^-3 A･m² / g and a coercivity of 46.2 kA / m. This method based on RF thermal plasma is advantageous over previous methods in suitability for large-scale production and the synthesized ceramic coated magnetic metal nanoparticles have wide applications in many fields.

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This study aims to understand granulation processes by fluidized bed numerically with Quality Engineering. The author defined a variety of drugs as a noise factor, designed experiment with L9 orthogonal array and conducted a model test.
Firstly, the author investigated distribution of drug content, spray liquid ingredient, constituent adherent to the inside of chamber. Secondly the author analyzed the distribution's result with Quality Engineering, and then calculated both sensitivities and signal-to-noise ratios. Finally the author confirmed its repeatability.
The results of analyses are as follows ; air volumes of fluidization and sprays are critical factors, which affect varieties of drug content significantly. Quantity of drug collected to filters is not related to drug content, but to control factors and types of drugs. It is necessary to control progress of granulation at the primary particle level in order to adjust contents distribution. In conclusion, numerical understandings of the above mentioned relation allows the author to optimize the distribution of drug contents.

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PLGA nanoparticles (NPs) have possibility to become the useful oral DDS for nucleic acid drug. The nanocomposite powder that PLGA NPs dispersed in matrix of excipient were prepared to make two kinds of solid dosage forms such as the enteric tablet and seamless capsule containing the NF-κB decoy nucleic acid loaded PLGA NPs for human oral administration model. These two solid dosage forms proposed here showed to be high applicable for the oral DDS.

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Since ancient times, people use "dry" to preserve foodstuff. The spray drying equipment which atomizes, and introduces a liquid solution of foodstuff into the hot wind and dries stuff, is widely used in the industrial sector. In spray drying, dry process and atomization are the most important factors. A comparison is introduced about various atomization methods and the outline of the importance and development of the atomization technology is described.

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The double cone type mixer is one of the typical container rotating mixers and it has been widely used due to its simple structure and easy for cleaning. However, dispersion speed of the materials at the axial part of container will be rather slow as they always rotate to only one direction. One of the major objectives to develop a new double cone type mixer, "Mugen Mixer" (model MM) was to solve this problem. Simply by inclining the cylindrical segment and setting the two cones asymmetrically, the double cone mixer offers high axial particle mobility, which results in high intermeshing action of the materials. In order to prove the outstanding characteristics and superior performances of "Mugen Mixer", the test results in numerical simulations, experimental mixing on test equipment and real-time monitoring of mixing state by using the Near-Infrared Spectroscopy (NIRS) are included in this report.

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