Transdermal delivery enhanced by antimicrobial peptides.

Magainin antimicrobial peptide has been shown to increase skin permeability by perturbing stratum corneum lipids in the skin. In this study, we hypothesized that skin permeation enhancement depends on peptide structure. We therefore measured skin permeability enhancement by modified magainin derivitives and 20 different antimicrobial peptides in a formulation containing ethanol and N-lauroyl sarcosine (NLS). We found that modification of magainin structure did not improve skin permeability enhancement. Although all six magainin-based peptides had alpha-helical structure and fluidized stratum corneum lipids, only magainin and a Gly-Ala substituted magainin with NLS and ethanol significantly increased skin permeability. Among the 20 antimicrobial peptides, only magainin itself and a Lys-Leu analog peptide showed enhancement. Overall, this is the first study to survey skin permeability enhancement by antimicrobial peptides. We conclude that over the range of conditions studied here, most antimicrobial peptides did not enhance skin permeability and that magainin peptide provided the optimal structure.