• Polymer(Korea)
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• v.33 no.1
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• pp.7-12
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• 2009

PLGA microspheres have been known as an injectable system for tissue engineering. The purpose of this study was to investigate the condition of emulsion formation and cell adhesion on the microsphere surface. BSA-loaded PLGA microsphere was fabricated by oil-in-water (O/W) and water-in-oil-in-water (W/O/W) solvent evaporation method. Sodium alginate was dissolved in water phase to control initial burst release and to improve lag time by PLGA bulk degradation. In addition, the morphology of cells attached on the micro spheres was studied using a scanning electron microscopy (SEM). Cellular proliferation behavior of human disc cells cultivated on PLGA micro spheres was analyzed using a MTT assay. MTT assay revealed that the cells can attach and proliferate on PLGA microspheres. According to these results, we concluded that BSA -loaded alginate/PLGA microspheres can be used as an injectable system for tissue engineering application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.399-399
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• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.295-305
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• 2004

Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.

• Journal of Life Science
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• v.19 no.1
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• pp.94-100
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• 2009

This study was carried out to examine the antimicrobial effects of grapefruit seed extract (GSE) and processed sulfur solution (PSS) against human skin pathogens: Malassezia furfur, M. restricta, Propionibacterium arnes, Trichophyton mentagrophytes and T. rubrum. The antimicrobial effects of GSE and PSS were tested by agar diffusion method and micro broth dilution method. As the results, the MIC values of GSE against M. furfur, M. restricta, P. acnes, T. mentagrophytes and T. rubrum were 3.91, 3.91, 0.004, 0.024, and $0.012{\mu}l/ml$, respectively. The MIC values of PSS were 0.03, 0.03, 0.156, 0.003, and $0.012{\mu}l/ml$, respectively. Antimicrobial activity of skin care emulsion products containing 0.5% GSE and 0.5% PSS against human skin pathogens were 5.2, 4.3, 8.0, 9.5 and 12.8 mm, respectively. Refractive index, pH, viscosity and color value of skin care emulsions containing GSE and PSS were measured. According to these results, it was concluded that the GSE and PSS were the promising sources of antibacterial agent which could be useful for skin and hair care products as well as for the alternative medicine development in treatment of certain types of skin ailments.