In addition, a diastereomer of Esc(1–21), named Esc(1–21)-1c, containing only two d-amino acid substitutions at the C-terminal region (dLeu14 and dSer17) was lately synthesized and found to be significantly more stable than the corresponding all-L peptide and less susceptible to enzymatic degradation (i.e. human and bacterial elastases)29; less toxic towards mammalian cells; more active against P. aeruginosa biofilms and more efficient in stimulating bronchial cells migration and presumably in restoring the integrity of an injured bronchial epithelium, a property which is not shown by any traditional antibiotic28, 30.