Reverse Iontophoretic Extraction of Skin Cancer-Related Biomarkers

Maxim Morin, Sebastian Björklund, Skaidre Jankovskaja, Kieran Moore, Begona Delgado-Charro, Tautgirdas Ruzgas, Richard Guy, Johan Engblom

Research output: Contribution to journalArticlepeer-review

3 Citations (SciVal)


Non-invasive methods for early diagnosis of skin cancer are highly valued. One possibleapproach is to monitor relevant biomarkers such as tryptophan (Trp) and kynurenine (Kyn), onthe skin surface. The primary aim of this in vitro investigation was, therefore, to examine whetherreverse iontophoresis (RI) can enhance the extraction of Trp and Kyn, and to demonstrate how theTrp/Kyn ratio acquired from the skin surface reflects that in the epidermal tissue. The study alsoexplored whether the pH of the receiver medium impacted on extraction efficiency, and assessedthe suitability of a bicontinuous cubic liquid crystal as an alternative to a simple buffer solution forthis purpose. RI substantially enhanced the extraction of Trp and Kyn, in particular towards thecathode. The Trp/Kyn ratio obtained on the surface matched that in the viable skin. Increasingthe receiver solution pH from 4 to 9 improved extraction of both analytes, but did not significantlychange the Trp/Kyn ratio. RI extraction of Trp and Kyn into the cubic liquid crystal was comparableto that achieved with simple aqueous receiver solutions. We conclude that RI offers a potential fornon-invasive sampling of low-molecular weight biomarkers and further investigations in vivo aretherefore warranted.
Original languageEnglish
Article number79
Issue number1
Early online date29 Dec 2021
Publication statusPublished - 31 Jan 2022


  • Bicontinuous cubic liquid crystals
  • Cancer-related biomarkers
  • Kynurenine
  • Non-invasive extraction
  • Tryptophan
  • Tryptophan-to-kynurenine ratio

ASJC Scopus subject areas

  • Pharmaceutical Science


Dive into the research topics of 'Reverse Iontophoretic Extraction of Skin Cancer-Related Biomarkers'. Together they form a unique fingerprint.

Cite this