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Research paper−169 Synthesiology - English edition Vol.1 No.3 (2009) hollow space within an organic nanotube is 10 times larger than that within a cyclodextrin; therefore, the former can incorporate large substances, such as proteins, nucleic acids, viruses, and metallic nanoparticles, that do not fit in the cavities of cyclodextrins. In previous studies, we incorporated gold nanoparticles (sizes: 1-20 nm)[3][4] and the spherical protein ferritin (diameter: 12 nm)[5] into organic nanotubes (Figure 2). Through their development and application in agriculture, foodstuffs, healthcare, medicine, and the environment, we suspect that organic nanotube-based materials will become new, commercially competitive products.The discoveries of the unique structures and properties of fullerenes (1984), which led to the award of the Nobel Prize in Chemistry in 1996[6], and carbon nanotubes (1991)[7] were major nanotechnological breakthroughs; R&D activity continues apace to develop the practical applications of these materials. Notably, although organic nanotubes were developed[8]-[10] in 1984—several years prior to the discovery 1 Research objectiveOrganic nanotubes are hollow-fiber substances formed through spontaneous aggregation (or self-assembly) of amphiphilic molecules that feature both water-soluble (hydrophilic) and oil-soluble (hydrophobic) moieties, much like surfactant molecules.Although the sizes of organic nanotubes differ according to the type of molecule used, in general they possess interior diameters of 10-200 nm, exterior diameters of 40-1000 nm, and lengths of up to several hundreds of micrometers[1].Amphiphilic molecules have good dispersibility in water because they possess a cylindrically arranged bilayer membrane structure with the hydrophilic parts facing the solvent (Figure 1).The cyclodextrins, cyclic molecules comprising six to eight glucose molecules arranged in a ring, are used widely in food, drug, and home products. Because various organic low molecular components can be incorporated within the hollow space of a cyclodextrin, unstable substances can be stabilized, drugs and fragrance can be released slowly, and substances that do not dissolve readily in water can be solvated[2]. The - Integration of molecular design, molecular synthesis and safety assessment for materials having market competitiveness-Masumi Asakawa*, Masaru Aoyagi, Naohiro Kameta, Masaki Kogiso, Mitsutoshi Masuda, Hiroyuki Minamikawa and Toshimi ShimizuNanotube Research Center, AIST Tsukuba Central 5, Higashi 1-1-1, Tsukuba 305-8565, Japan *E-mail : Organic nanotubes are hollow fibers formed through the self-assembly of amphiphilic molecules in a solvent. Because nanoparticles and proteins can be included within their hollow interiors, such nanotubes can be applied to a wide range of fields. To promote the practical use of organic nanotube, we have developed a strategic scenario that fulfills several conditions, including mass synthesis (by integrating molecular design, synthesis, and self-assembly technologies), practical use, low cost, and safety.Development of massive synthesis method of organic nanotube toward practical useKeywords : Organic nanotube, mass synthesis, self-assembly, inclusion, safety assessment[Translation from Synthesiology, Vol.1, No.3, p.183-189 (2008)](15)−Fig. 1 Schematic representation of the formation of the organic nanotube structure.Fig. 2 TEM images displaying the inclusion of (left, middle) gold nanoparticles of various sizes and (right) the spherical protein ferritin within organic nanotubes.Amphiphilic moleculesOrganic nanotubeHydrophilicHydrophobic1-3 nm12 nm15-20 nmGold nanoparticlesFerritinEnergy/ keVFeKaCuKa7896

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