Session: Session 5

Hyaluronic acid detection and relative quantification by mass spectrometry imaging in human skin tissues

Raphael LEGOUFFE¹, Olivier JEANNETON², Mathieu GAUDIN¹, Aurore TOMEZYK¹, Amandine GERSTENBERG¹, Marc DUMAS², Catherine HEUSÈLE², David BONNEL¹, Sylvianne SCHNEBERT²

¹Aliri, LOOS, France
²LVMH Recherche, St Jean de Braye, France

INTRODUCTION:

In this study, MALDI Mass Spectrometry Imaging has been used to study global (endogenous and exogenous) Hyaluronic Acid (HA) distribution and relative quantification within skin tissue to support the development of a cosmetic product.

METHODOLOGY:

Human skin tissue samples were topically treated for 6 days with a cosmetic formula containing HA or not (placebo). At the end of the preparation step, the surface of the explants was washed and the samples were snap frozen. Tissue sections at 10µm of thickness were prepared in a cryostat at -20°C and mounted on ITO slides for analysis.

The hyaluronidase enzyme was sprayed at 300 Units/mL onto the tissue sections with the TM-sprayerTM system before an 18 hour digestion at 37°C. After the incubation, MALDI matrix was sprayed with the same device over the tissue sections. These slides were analyzed with a 7T MALDI-FTICR.

RESULTS:

After enzymatic digestion, HA was detected within each skin section (control, placebo and treated). HA signal localization and intensity within the tissue sections was different between the groups, highlighting the impact of the formulation containing HA. For the control and placebo tissues, the signal was mainly localized in the epidermis and in the first layers of the dermis whereas for the treated tissues, HA was detected in the entire section (i.e. epidermis, upper dermis and lower dermis). These results confirm the efficacy of the formulation to increase the HA level in the skin layers and to conclude on an effective tissue exposure.

CONCLUSION:

We described for the first time a detailed workflow for HA detection within skin tissue by MALDI-FTICR Mass Spectrometry Imaging. The workflow combined the specificity of the MALDI-FTICR Mass Spectrometry Imaging and histology to measure the HA increase in the different skin layers (i.e. epidermis, upper dermis and lower dermis) after treatment and to conclude on the benefit of cosmetic formula containing HA to increase HA content in the dermis.