The scratch assay is relevant to evaluate the efficacy of active ingredients for irritated skins as well as for stretch marks. In cosmeto dermatology, this assay is commonly used to assess compounds efficiency on wound healing process (Heng, 2011).

We have developed a 96-well plate automated assay to allow screening and easy comparison between different active ingredient or compounds mixes.

Wound Healing

Figure 1 : Overview of scratched 96 well plate using our automated microscope.

Assessment of primary human keratinocytes wound healing process has been validated in R&D service of HCS Pharma. Thought the use of our automated assay, we evaluated the effects of further reference compounds according to bibliography (Liu et al., 2009; 2016).

wound-healing_results

Figure 2 : Effects of reference compounds on keratinocytes wound healing. (RA = Retinoic Acid; GG = Glyceryl Glucoside; Nic = Nicotinamide; Ins = Insuline; w/o EGF = Without EGF). Results illustrated 5 independents experiments and are compared to control condition using a T test (* = p<0,1).

We can also provide further investigation on demand. Scratch assay could be followed by immunocytochemistry analysis of keratinocytes phenotypes.

Wound healing process is a complex phenomenon involving several cellular response, including inflammation, proliferation, and cell differentiation. Here, we study the presence of a water and glycerol transporter the Aquaporine 3. This transporter is involved in skin hydration, and increased barrier function of healthy skins (Schrader et al., 2012). Localization of AQP3 in the wound area of glyceryl glucosid exposed keratinocytes can assessed using our guided images acquisition and analysis HCA system.

aquaporine & wound-healing

Figure 3 . Enhanced AQP3 production in keratinocytes in the wound area. Nucleus are stained in blue, and aquaporine 3 in Green.

All our studies conduct in dermatocosmetology can also be done using the human keratinocytes cell line HaCaT. This cell line has been wildely used to study human keratinocytes cellular process, such as differentiation or wound healing (Deyrieux and Wilson, 2007; Song et al., 2008).

For further information about our wound healing assay, contact us!

Bibliography :

Deyrieux, A.F., and Wilson, V.G. (2007). In vitro culture conditions to study keratinocyte differentiation using the HaCaT cell line. Cytotechnology 54, 77–83.

Heng, M.C.Y. (2011). Wound healing in adult skin: aiming for perfect regeneration. Int. J. Dermatol. 50, 1058–1066.

Liu, Y., Petreaca, M., Yao, M., and Martins-Green, M. (2009). Cell and molecular mechanisms of keratinocyte function stimulated by insulin during wound healing. BMC Cell Biol. 10, 1.

Schrader, A., Siefken, W., Kueper, T., Breitenbach, U., Gatermann, C., Sperling, G., Biernoth, T., Scherner, C., Stäb, F., Wenck, H., et al. (2012). Effects of Glyceryl Glucoside on AQP3 Expression, Barrier Function and Hydration of Human Skin. Skin Pharmacol. Physiol. 25, 192–199.

Song, X., Xu, A., Pan, W., Wallin, B., Kivlin, R., Lu, S., Cao, C., Bi, Z., and Wan, Y. (2008). Nicotinamide attenuates aquaporin 3 overexpression induced by retinoic acid through inhibition of EGFR/ERK in cultured human skin keratinocytes. Int. J. Mol. Med. 22, 229–236.

(2016). Cosmeceuticals and active cosmetics (Boca Raton: CRC Press, Taylor & Francis Group).