862 Pain, itch and quality of life in persons with keloids

Abstract

United StatesMelanoDermÔ, supplied by MatTek Corporation, Ashland, MA is a commonly used in vitro model to test a formula or ingredient's impact on melanin and therefore their ability to even or lighten skin tone. MelanoDermÔ is a 3D constructed, live, manufactured skin culture that is widely used as a screening tool in the cosmetic industry to study melanogenesis and pigmentation. In this study, we evaluated well-known cosmetic compounds i.e. hydroquinone and kojic acid causing effects on melanin and melanogenesis in vivo, as relevant benchmark positive controls for in vitro screening architecture of other actives alone or in combination. Hydroquinone was tested in water solution as a single ingredient or as finished goods formulation at the concentration of 2% and Kojic Acid was investigated in water solutions at two different concentrations (1% and 2%) for their ability to reduce existing and new pigment formation on MelanoDermÔ (MEB-300B) tissues after 14 days of topical application. Cell viability was assessed with MTT assay, color measurements (L*, a*, b* values) with chromameter, and in situ histology of the selected tissues was performed with Hematoxylin and Eosin staining. Hydroquinone evaluation in this model was somewhat challenging due to its known cytotoxicity geared specifically towards melanocytes, while kojic acid was safe at the concentration of 1%. Generated data indicate that both actives may be used as positive controls and thus serve as a validated model in screening architecture of the new perspective skin lightening/brightening actives and represent a translation platform between vitro-to-vivo studies. It is well known that the cosmetic property of evening skin tone can help reduce the visible signs of aging on photodamaged skin. Photodamage originates from a variety of environmental aggressors including UV exposure, high energy visible light, and pollutants. Mel-anoDermÔ is a commonly used in vitro method to test a formula or ingredient's impact on melanin and therefore ability to even skin tone. MelanoDermÔ, supplied by MatTek Corporation, Ashland, MA, is a 3D constructed, live, synthetic skin culture that is widely used in the cosmetic industry. L-ascorbic acid is a known reactive oxygen species (ROS) scavenger and is often claimed to even skin tone through several biological pathways, including its ability to interrupt melanin synthesis by interacting with the copper ions at the active site of the enzyme Tyrosinase, a key enzyme in melanogenesis (pheomelanin and eumelanin); an increase in the amount and location of melanin in the skin is responsible for areas of uneven skin tone, and thus the appearance of aged skin upon exposure to environmental aggressors. This study was designed to test several topical dermatologics containing different levels of Lascorbic acid, and its esters, along with other ingredients in their ability reduce melanin pigment and its further formation on MelanoDermÔ (MEL-300B) tissues after 14 days of topical application. The CIE L*a*b* values were recorded with S...