Polycyclic, highly-conjugated, and ortho-fused aromatic compound, 9-tetraethyleneglycoxy-11-oxa[9]helicene (TO9H), was synthesized and used to explore the feasibility of fabricating thin films and the photoelectrochemical properties of resultant films. Since TO9H has both the hydrophobic helicene part and the hydrophilic tetraethyleneglycoxy (TEG) chain, it behaved as a water-insoluble amphiphile and hence formed a stable Langmuir monolayer at the air–water interface. Homogeneous films with thickness up to a few hundred angstroms were deposited by using a spin-coating method. Both of the monolayers and the spin-coated films were characterized by several methods. Brewster angle microscopic (BAM) images and atomic force microscopic (AFM) topographic images revealed the homogeneous surface of the TO9H monolayer at the air–water interface and of the deposited monolayer and films on solid substrates, respectively. By using an X-ray reflectivity (XR) technique, the thickness, roughness, and electron density of layers or films were determined. The photocurrent evolution was measured using conventional three-electrode systems with light irradiation from a xenon lamp and obtained results showed that the compound TO9H generated a substantial amount of photocurrent under illumination of light.

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Mixed micellar nanoparticle consisting of amphotericin B (AmB) and poly styrene-block-poly ethylene oxide (PS-block-PEO) was prepared by high pressure homogenizer. Nephrotoxicity of the nanoparticle was investigated along with antifungal activity and self-aggregation status of the drug in the nanoparticle. Nephrotoxicity was markedly reduced when AmB was intravenously administered to rats as mixed micellar nanoparticle with PS-block-PEO in terms of transmission electron microscopy of tubular cells and creatinine clearance. Antifungal activity of AmB was not altered when the drug was in the form of mixed micellar nanoparticle compared to both conventional formulation and AmB micelle treated by same procedure without PS-block-PEO. Self-aggregation status of AmB molecules revealed monomeric in the mixed micellar nanoparticle with PS-block-PEO up to the therapeutic level of the drug (1-3 mM). The reduced nephrotoxicity of AmB in mixed micellar nanoparticle may be associated with the existence of the drug as monomeric form in the nanoparticle. Based on our result, formulation of AmB as mixed micellar nanoparticle with PS-block-PEO may be a promising alternative for the treatment of fungal diseases in patients who are at risk of renal dysfunction.

A highly π-conjugated helical compound, 11-oxa [9]helicene (O9H), and its derivative 9-diethyleneglycoxy-11-oxa[9]helicene (2EO9H) were used to prepare thin films by the Langmuir technique, and their structures and photoelectrochemical properties were evaluated. Brewster angle microscopic (BAM) observation implied that 2EO9H molecules formed a homogeneous, flat monolayer but O9H molecules three-dimensionally aggregated at the air-water interface. The same morphological features were also observed for films deposited on silicon wafers using atomic force microscopy (AFM). The film structures on solid supports were estimated by X-ray reflectivity (XR) measurements. The XR fitting analysis and theoretical calculation suggested that in the 2EO9H monolayer the hydrophobic aromatic planes of helicene moiety oriented perpendicularly to the monolayer plane and the hydrophilic diethyleneglycoxy group (DEG) was bended/twisted. It was also indicated that optical band gaps estimated from UV-visible spectra are not much changed due to introduction of DEG chain to the O9H moiety, but the 2EO9H monolayer showed larger photocurrent densities.

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