Iron concentrations in human dermis assessed by microdialysis associated with atomic absorption spectrometry

Until recently, the determination of metallic elements concentrations in normal skin, in vivo, was rare due to the lack of non-invasive techniques. Microdialysis has the advantage of being slightly invasive when applied to the collection in vivo of endogenous or exogenous substances from the skin. Iron is an active element in different cutaneous disorders. The aim of this work was to assess iron by atomic absorption spectrometry (AAS) after the collection of samples by microdialysis from human dermis. A first essential step, before determining the in vivo iron concentration in human dermis, was to establish an experimental protocol applicable to ex vivo as well as in vivo conditions. For this reason, this work deals only with the assessment of iron in ex vivo human dermis. A skin microdialysis technique and a calibration method, the No Net Flux, were used to quantify basal iron concentrations in human dermis and the same method was also used to determine in vitro and ex vivo iron recoveries. No differences were detected between in vitro and ex vivo recoveries. Ex vivo basal iron dermis concentrations ranged from 3.6 to 7.7 microg/l. This study shows that non-invasive microdialysis is an efficient method for sampling iron from human skin. A sensitive and accurate AAS technique was able to assess low iron concentrations in human dermis. The strategy adopted for this work was efficient and appropriate for the determination of iron in human skin and experiments will be carried out in vivo.