Solubilization mechanism of α-glycosylated naringin based on self-assembled nanostructures and its application to skin formulation.

We previously reported that α-glycosylated naringin (naringin-G), synthesized by enzyme-catalyzed transglycosylation, can enhance the solubility of poorly water-soluble compounds without surface-active property. However, the solubilization mechanism has not been fully elucidated. In this study, the solubilization mechanism of naringin-G was investigated using nuclear magnetic resonance (NMR) spectroscopy, and its application in skin formulations was further investigated. 1H NMR and dynamic light scattering measurements at various concentrations confirmed the self-assembled nanostructures of naringin-G above a critical aggregation concentration of approximately 2.2 mg/mL. Two-dimensional 1H-1H nuclear Overhauser effect spectroscopy and solubility tests revealed that flavone with poor water solubility, could be solubilized in its self-assembled structure with a stoichiometric relationship with naringin-G. When naringin-G was included in the skin formulation, the permeated amount and permeability coefficient (Papp) of flavones improved up to four times with increasing amounts of naringin-G. However, flavone solubilization by adding an excessive amount of naringin-G resulted in a decreased permeated amount and Papp of flavones, indicating the interplay between the apparent solubility and skin permeability of flavones. Naringin-G, which forms a nanoaggregate structure without exhibiting surface-active properties, has the potential to enhance the solubility and skin permeation of poorly water-soluble compounds.

Structure consideration of platinum nanoparticles constructing nanostructures obtained by electrochemical dealloying of a Cu-Pt alloy.

Many nanoporous metals have been applied for catalysis and show active properties. In this study, nanoporous platinum was successfully prepared from a Cu-Pt (50/50 w/w) alloy plate by electrochemical dealloying. In order to reveal their detailed structures in nanometer order, TEM observation of the surface area of the alloy plate was performed by using focused ion beam (FIB) for sample preparation. Peeling off the surface platinum nanoparticles could be also successfully preformed by using ultra sonification and their TEM observation revealed the units of the platinum nanoporous structures.