title: Cortisol extraction through human skin by reverse iontophoresis.
abstract: Continuous monitoring of cortisol at the surface of the skin would advance the diagnosis and treatment of cortisol-related diseases, or of elevated cortisol levels related to stress in otherwise healthy populations. Reliable and accurate detection of cortisol at the skin surface remains a limiting factor in real-time monitoring of cortisol. To address this limitation, cortisol extraction through excised human skin by reverse iontophoresis was studied in vitro in side-by-side diffusion cells using a radiolabeled probe. The skin was subjected to four direct current regimens (0, 28, 56, 113μAcm-2) with the anode in the donor chamber and the cumulative cortisol concentrations recorded in the receiver chamber. The 56 and 113μAcm-2regimens significantly increased transport of3H-cortisol through the skin, and current density correlated directly with transcutaneous transport of3H-cortisol. The threshold of detection of electroosmotic versus passive diffusion of cortisol through the skin was between 28 and 56μAcm-2. The results of this study are significant in examining how lipophilic analytes found in the bloodstream respond to reverse iontophoresis across the skin. In addition, a device integration technique is presented which illustrates how continuous cortisol extraction and sensing could potentially be achieved in a conventional wearable format.
authors.affiliation: James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH 45267-0004, USA. Electronic address: ventursa@mail.uc.edu.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Ventura
authors.affiliation: College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH 45219, USA. Electronic address: heikenjc@ucmail.uc.edu.
authors.forename: Jason
authors.initials: J
authors.lastname: Heikenfeld
authors.affiliation: College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH 45219, USA. Electronic address: brookst5@mail.uc.edu.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Brooks
authors.affiliation: College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH 45219, USA. Electronic address: esfandla@ucmail.uc.edu.
authors.forename: Leyla
authors.initials: L
authors.lastname: Esfandiari
authors.affiliation: College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA. Electronic address: boycest@ucmail.uc.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Boyce
authors.affiliation: College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH 45219, USA. Electronic address: parkye@ucmail.uc.edu.
authors.forename: Yoonjee
authors.initials: Y
authors.lastname: Park
authors.affiliation: James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH 45267-0004, USA. Electronic address: Gerald.Kasting@uc.edu.
authors.forename: Gerald B
authors.initials: GB
authors.lastname: Kasting
mesh_terms: D004058:Diffusion; D053841:Electroosmosis; D006801:Humans; D006854:Hydrocortisone / Q000737:chemistry / Q000302:isolation & purification*; D007478:Iontophoresis / Q000379:methods*; D010539:Permeability; D012867:Skin / Q000737:chemistry*; D013997:Time Factors
chemical_list: D006854:Hydrocortisone
keywords: Biomonitoring; Cortisol; Electroosmosis; Reverse iontophoresis; Skin sensor