(I) E 0 U) 0 � SKIN PENETRATION BY COPPER-PEPTIDE COMPLEXES 65 2,50 2,00 ';"(I) •E 1,50 0 U) 0 � 1,00 0,50 0,00 Cu2+ GSH-Cu GHK-Cu Figure 2. The influence of peptide complexes on the permeability of copper ions. 0,020 0,015 0,010 0,005 0,000 GHK-Cu GHK GSH-Cu GSH Figure 3. The influence of complexation on the permeation coefficients of peptides GHK and GSH. The tripeptide GHK was identified by a mass spectrum, in which a signal at m/z 339 was registered and identified as a quasi-molecular ion of GHK (Figure 4a). A signal for GSH compound was registered at m/z 306 (Figure 46). ESI-MS study proves that tripeptides GHK and GSH penetrate from the emulsion through the modeling stratum corneum membrane (Table I). The GHK-Cu complex from the emulsion penetrates in different forms, like tripeptide GHK and GHK-Cu (Figure 5a). The mass spectrum for these studies consists of two signals at m/z 339 for GHK and 400 for GHK-Cu. These results are similar to those in our investigations for aquae's solution (25) and show the influence of the structure of the complexes on the penetration ability of the copper tripeptide complexes. This can suggest that GHK-Cu is the most important species in the penetration ability of copper complexes with GHK. It can be confirmed by the fact that the permeability coefficient K P for copper from the GHK-Cu complex is higher than that for copper ions alone. All the signals were compared to the theoretical profiles. The ESI-MS results for the penetration ability of the GSH-Cu complex show that the compounds that penetrate through the membrane are GSH and a very small amount of

66 a) 100 80 60 % 40 20 0 __ t JOURNAL OF COSMETIC SCIENCE b) 100 � 80 53' = I = % Q. 40 i � ') ai ') ') Jl1.L1H�_L. 20 JL 0 200 400 m/z 200 Figure 4. Mass spectra for (a) GHK and (6) GSH from emulsion in acceptor cells. Table I Ionized Species Observed in ESI-MS Spectra of GHK-Cu and GSH-Cu Solutions Positive ion Negative ion mlz Proposed ion mlz Proposed ion 341 [GHK + H} + 339 [GHK + H}- 402 [CuGHK + H} + 400 [CuGHK - H} 306 [GSH - Hr 304 [GSH - Hr 369 [GSH - Hr 367 [GSH - Hr 400 m/z GSH-Cu (Figure 56). The mass spectrum for these studies consists of two signals at mlz 306 for GSH and 369 for GSH-Cu. The participation of the GSH ligand form in the penetration ability of copper shows the important role of these species in the transport process. The ligand influence can be confirmed by the fact that the K P for copper from these complexes is lower than for copper from the GHK-Cu complex. All signals were compared to the theoretical profiles. This result supports the thesis that copper com­ plexes with bioligands can be formed and penetrate through the model membrane from the emulsion. CONCLUSIONS The biological activities of the copper tripeptide complex play an important role in the protection and regeneration of skin tissue, and GHK-Cu and GSH-Cu are a very good copper ion source. The research on copper transport through membrane modeling stra­ tum corneum proved that the tripeptide-copper complex may permeate through a horny layer of epidermis. GHK significantly participates in the wound-healing process: due to its properties it influences the elasticity and strength of the skin. What's more, GSH play a very