Development of a Preclinical Tool for Measuring Percutaneous Transfer of Dihydrogen, with a View to Optimizing Medical Devices Adapted to Focal Therapies in Dermatology

Numerous studies have demonstrated the efficacy of dihydrogen (H2) in dermatological pathologies, with no attributed adverse effects. However, there is no formal proof of percutaneous transfer of H2 through the skin. The aim of the present study is to demonstrate this transfer and to characterize the H2 diffusion coefficient in the skin. Rat abdominal skin is affixed to the center of a diffusion cell. In a first compartment, a gas mixture containing different proportions of H2 combined with air is injected. A second compartment contains either air or physiological medium + air. A H2 sensor is connected to the second compartment and records H2 concentration. A bi-exponential model of H2 concentration is then fitted. The mean value of the flow is 0.40 nmol.s−1.cm−2, and the mean value of the H2 diffusion coefficient is 4.2 10–5 cm2.s−1, which is very close to H2 diffusion coefficient in water (D = 4.58 10–5 cm2.s−1). Our model confirms the major interest of designing new approaches to deliver H2 for dermatology applications, because the local concentration of H2 in the target zones will be by several orders of magnitude higher than what can be achieved with oral administration.