Evaluation of dermal extracellular matrix and epidermal-dermal junction modifications using matrix-assisted laser desorption/ionization mass spectrometric imaging, in vivo reflectance confocal microscopy, echography, and histology: effect of age and peptide applications

J Cosmet Dermatol. 2015 Jun;14(2):152-60. doi: 10.1111/jocd.12135. Epub 2015 Mar 27.


This study was conducted to establish a new methodology for evaluating elements of dermal extracellular matrix (ECM), of epidermal-dermal junction (EDJ), and effects of molecules which can modulate their synthesis. This methodology is based on matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI). In vivo reflectance confocal microscopy (in vivo RCM) and echography were also used. Using immunohistochemistry methods on explants, age-related modification data were obtained for selected dermal ECM and EDJ proteins (collagen I, collagen IV, collagen VII, collagen XVII, nidogen I, decorin/decorunt) and used as reference for MALDI-MSI studies. A methodology was developed with MALDI-MSI to map epidermis and dermis proteins. Then MALDI-MSI was used to study age modifications. In vivo RCM and high-frequency ultrasounds were used to evaluate ECM and EDJ undulation modifications caused by aging. Anti-aging molecule evaluations were performed with a blend of palmitoyl oligopeptide and palmitoyl tetrapeptide-7. Immunohistochemistry studies demonstrated that the selected proteins were found to be less abundant in aged group explants vs. young group except for decorin. MALDI-MSI studies correlated the results obtained for decorin. In vivo RCM measurements indicated a decrease of EDJ undulation depth with age and ECM modifications in the upper part of dermis. Echography demonstrated that the peptide blend reduced subepidermal low-echogenic band thickness and improved its density. In vivo RCM studies indicated that the peptides improved the ECM structure vs. placebo. This preliminary MALDI-MSI study raised some technical difficulties that were overcome. Further studies will be conducted to identify more proteins and to demonstrate the interest of this method for cosmetic evaluations.

Keywords: confocal microscopy; cosmetic efficacy; evaluation methods; measuring methods; skin structure; spectrophotometry.

MeSH terms

  • Adult
  • Aged
  • Aging / metabolism*
  • Collagen / metabolism
  • Decorin / metabolism
  • Dermis / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Epidermis / metabolism*
  • Extracellular Matrix / metabolism*
  • Extracellular Matrix Proteins / metabolism*
  • Female
  • Humans
  • Immunohistochemistry
  • Membrane Glycoproteins / metabolism
  • Microscopy, Confocal
  • Middle Aged
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Ultrasonography


  • Decorin
  • Extracellular Matrix Proteins
  • Membrane Glycoproteins
  • nidogen
  • Collagen