Abstract
Sacran is a sulfated polysaccharide isolated from an alga, Aphanothece sacrum (Suizenji-nori). Sacran shows unique characteristics in which the molecular weight and the length of one molecular are 29 MDa and about 10 μm, respectively. The chemical characteristics are expected to show skin protection properties due to film formation. We found that sacran formed a gel-like film which was hard to re-dissolve in water. Furthermore, the gel-like film formed in the presence of polyols such as 1,3-butylene glyco (1,3-BG) exhibited superior properties on aspects of skin protection to those in the absence of polyols. We named this film structure the “gel-sheet”. The gel sheet decreased the water evaporation rate and the penetration of chemicals. The results suggested that the gel-sheet works as an artificial barrier on the skin surface. In addition, we found that sacran-polyol complex emulsified oils and the emulsification potentials depended on the chemical structures of the polyols. Moreover, sacran-polyol complexes were able to emulsify oils without depending on their polarities. As a result, it was concluded that sacran-polyol complexes formed the gel-sheet after drying and also worked as an emulsifier. Therefore, we expected the sacran-polyol complexes to protect the skin.
