The role of sophorolipid as carrier of active substances

Sophorolipid is a glycolipid-type biosurfactant, produced from natural sources by fermentation with a nonpathogenic yeast Starmerella bombicola. Its structure is composed of 2 hydrophilic parts, a sophorose unit, a glucose disaccharide glycosically linked to a hydroxyl fatty acid. Its structure spontaneously forms a vesicle of about 100 nm in an aqueous solution, which is similar to that of liposomes used as drug delivery systems and transdermal absorption promoters. It can be expected to have an effect of promoting permeation of active substances such as lactoferrin. Lactoferrin is an iron-binding glycoprotein having a molecular weight of about 80 kDa, and is most abundant in breast milk in the living body. Since it is also present in amniotic fluid that protects the mother and fetus, it is important to study the physiological relationship between skin and lactoferrin. The transdermal administration of lactoferrin with sophorolipid was verified, followed by the investigation protein-surfactant interactions between bovine lactoferrin and sophorolipid. Structural changes were further observed using spectroscopic, microscopic and biochemical methods under weakly acidic and neutral pH conditions. From particle size analysis by dynamic light scattering, microscopic observation by cryo-SEM, and digestion pattern observation by enzyme treatment, it was confirmed that bovine lactoferrin and sophorolipid interact with each other to form a sheet and nanometer-sized coagulation at pH 5.0 and 7.0 forming an aggregate, which was considered to be due to the self-organizing structure characteristic of sophorolipid. It can be concluded that sophorolipid has a potential of being a transport carrier of active substances, which can have vast applications not only in cosmetics but in drug delivery systems as well. Biosurfactants and biopolymers: Between interactions, orthogonality and mutual