Pigment Research Using In Vitro Models (For Professionals)

• Mattek is a company which produces artificial skin models and the authors show application for pigmentary disorders models such as melasma (chloasma, pregnancy mask) and postinflammatory hyperpigmentation.

• In the study the authors used MelanoDermTM, which is a three-dimensional tissue culture model of human epidermis that contains normal human melanocytes (NHM) and keratinocytes (NHK). The origin of donors (African American, Asian) as well as phototype were recorded.
• Several over-the-counter skin lightening products were evaluated (Kojic acid, magnesium ascorbyl phosphate or ascorbyl glucoside)
• Tissues were treated topically three times a week over a two to three week treatment period to mimic consumer application.
• The skin lightening effect on treated tissues was quantitatively evaluated for melanin content using both a solvable melanin assay and spectrophotometric measurement.

• Results show that tissues treated topically with cosmetic skin lightening agents containing remained distinctly lighter than control cultures.  Control cultures (treated with water only) on the other hand progressively became increasingly pigmented with retention of normal epithelial morphology.
• Treated tissues showed varied although significant changes in overall melanin content (reductions of 12–21%) compared to water-treated tissues (control cultures)

Comment:

• MelanoDerm offers a good compromise for research on human resembling skin especially in all the ethical requirements to develop a cosmetic product
• However it is probably not as accurate as in vivo in humans, or in animals.
• In vitro: It is probably the most accurate method. It is much better than researching single cell cultures where conclusions tend to be more haphazardous to verify.

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

Source of Information: M Bachelor, B Breyfogle, E Gustafson and M Klausner MatTek Corporation, Ashland, MA, USA. An epidermal model containing functional melanocytes for skin lightening and pigmentation disorder studies. International Investigative Dermatology (IID) 2013 – Edinburgh, United Kingdom