What does efficacy mean?

The overall definition for efficacy is the capacity to produce an effect, e.g. a beneficial change by a given treatment in healthcare studies or a maximum response achievable from a drug to produce a certain (beneficial) effect in pharmacological studies.

What are possible efficacy applications for reconstructed human epidermis models?

The use of reconstruced human epidermis shows clear advantages over "normal" monolayer cell cultures which grow under submerse conditions. Due to their three-dimensional growth and the differentiation from proliferating basal cells into cornified upper layers, these models closely mimic normal human skin.

Some example applications:

  • Barrier function
  • Transepithelial resistance
  • Differentiation markers (e.g. Filaggrin, Cytokeratins,Transglutaminase, Loricrin)
  • Protein markers
  • Collagen structure
  • Photo damage
  • Transepidermal water loss
  • Elasticity/Firmness

Additional examples using pigmented epidermis models:

  • Lightening
  • Tanning, pigmentation
  • Melanin studies

Topical exposure of test substances at the air liquid interface as well as baso-lateral exposure into the culture medium allows a variety of different experimental set-ups. For a specific application a lot of different approaches and experimental set-ups should be considered to conduct the most efficient and meaningful investigation. E.g. the choice of cells or skin models of interest, the application of test substances into the culture medium or topical exposure onto the surface of the tissues, as well as the exposure duration and possible intervals between repeated exposures.