Study of the composition and structure of pig stratum corneum based on the action of different solubilizing agents

Abstract

The composition and structure of pig stratum correum (SC) tissue were investigated using different solubilization methods. Whereas chloroform-methanol mixtures resulted in an almost complete removal of the intercellular lipids of the SC tissue and a small amount of proteins, the action of the nonionic surfactant octyl glucoside (OG) at concentrations lower and higher than its critical micelle concentration (CMC) led to the disaggregation of the SC tissue due to the solubilization of the corneocyte envelope. From a structural viewpoint, the intercellular lipids were bound one to another by means of hydrophobic interactions and the amino acids building the keratinocyte envelopes were linked covalently to these lipids (predominantly ceramides). The material extracted by organic solvents was able to form liposomes (proteoliposomes), whereas that solubilized using OG surfactant (richer in proteins) did not form these structures. Two different approaches may be envisaged in the interaction of the OG and organic solvents with the SC tissue. On the one hand, the OG can be considered as a preferential and selective agent with respect to the use of organic solvents to obtain more specific information on the assembly properties of the lipids and amino acids building the corneocyte lipid envelope. On the other hand, the organic solvents appear to be specifically suitable for studying the lipid building the intercellular SC matrix. In addition to the generally accepted assumption that organic solvents exert a protein denaturing influence, it was demonstrated that the action of chloroform-methanol mixtures does not affect the architecture of the SC tissue, whereas the OG leads to its disaggregation.