Establishment of a novel in vitro viable human skin model as a basis for the treatment of human and veterinary chronic skin diseases

Abstract Transdermal drug delivery avoids first-pass metabolism and provides decreased toxicity risk and higher patient compliance compared to gastrointestinal drug administration. Drug development may be significantly shortened by transfer from in vivo to in vitro testing. The aim of this pilot study was to obtain a viable in vitro human skin model, employable for drug development of new formulations for the treatment of cutaneous diseases. Herefore several skin specimens were cultivated under simplest conditions serum-free over 14 days in unsupplemented Dulbecco's modified Eagle's medium at 37 °C/5% CO 2 with the stratum corneum at the air liquid interface. Skin viability was determined with the lactate dehydrogenase (LDH) release assay which is generally designed for cell culture systems. The second aim of this study was therefore the modification of a commercial LDH assay for tissue application. The results of skin cultivation demonstrate, that the skin specimens could be kept at a viability level of ≥60% for the first seven cultivation days, followed by a sharp decrease afterwards, being comparable to studies with more complex cultivation conditions. The LDH measurement method was validated, hence it was concluded that the modified assay can be a reliable and useful tool for the viability evaluation of skin tissues.