Within two days after inflicting injury, a membrane-like structure had formed in the wound area. This structure did not appear to be epithelial in nature and formed on the basis of the wound. One or two mice from each group were sacrificed on day 4, and their dorsal skin was sampled to examine the phenomenon (Fig. ). The membrane-like structure consisted mainly of fibroblasts with occasional keratinocytes found on the wound's edges in skin treated with RADA16-I, RADA-IM, RADA-GHK, and RADA-KGHK. All the applied hybrid peptides significantly increased the thickness of the membrane in comparison to RADA16-I. Statistical analysis proved the differences between the control treated with RADA16-I and those treated with peptide-hybrids to be significant (p-value <0.001), except for skin treated with RADA-GHK (Fig. ). The RADA-IM and RADA-KGHK peptides promoted formation of the membrane-like structure most effectively.