Visit Us at SID 2017 at Booth #103
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Poster Session I: Thursday Morning, 4/27, 10:15 AM-12:15 PM
Abstract 825 Measurement of Skin Pigmentation Using a Chromameter in a 3-Dimensional Epidermal Model Containing Functional Melanocytes
B Breyfogle, M Bachelor and M Klausner
MatTek Corporation, Ashland, MA
Various cosmetic or skin care pharmaceutical formulations augment skin pigmentation either for the intended purpose of skin lightening or as an off target drug effect. A convenient way to screen such effects utilizes MelanoDerm, a highly differentiated, three-dimensional tissue culture model of human epidermis containing normal human melanocytes and keratinocytes. Use of this model can provide valuable in vitro data as an early screening tool prior to the commencement of costly clinical trials. In this study, pigmentation was evaluated over the course of 2-3 weeks using a tristimulus chromometer to measure brightness (L*), yellowness (b*) and redness (a*) in MelanoDerm tissue produced with normal human melanocytes from Black, Asian, or Caucasian donors. In parallel to measurements taken with the chromameter, total melanin content of tissues was also quantified. Over time, cultures became increasingly pigmented with retention of normal epithelial morphology with the expected pigmentation level of the donor tissue, i.e. Black>Asian>Caucasian when cultured in media containing alpha-MSH and beta-FGF. Several OTC skin lightening products were also evaluated in cultures containing normal human melanocytes from Black donors. Over the 2-3 week treatment period, control cultures became increasingly pigmented while tissues treated topically with cosmetic skin lightening agents containing tyosinase inhibitors such as kojic acid and magnesium ascorbyl phosphate remained distinctly lighter when compared to control cultures. After 14 days in culture, total melanin content was found to inversely correlate with surface reflectance (L*). The results described herein suggest that this model is useful for evaluating melanogenesis, skin lightening, and other pigmentation phenomena of skin in vitro. In particular, this study highlights two distinct endpoints, total melanin content and skin color measurement that can be used to evaluate skin pigmentation in vitro.
Poster Session II: Friday Mid-Morning-Early Afternoon, 4/28, 11:30 AM – 1:30 PM
Abstract 460 Development of an In Vitro Method to Evaluate the Skin Hydration Potential of Topical Formulations
M Bachelor, K Guntur, A Plotkin, J Oldach and A Armento
MatTek Corporation, Ashland, MA
Skin hydration is vital in maintaining the barrier function of skin. Moisturizers, including creams, gels and lotions contain substances that both promote retention of water and reduce water loss from the skin. Current moisturizer product development is limited to expensive and highly variable human clinical studies and cell based models which lack relevant tissue structure and function. In addition, cell based models restrict potential test compounds/formulations due to solubility issues. In this study, EpiDermFT, an in vitro 3D human skin model, was used to evaluate the skin hydration potential of several commercially available skin moisturizers. EpiDermFT is cultured at the Air-liquid Interface and is amenable to topical exposures of test compounds or formulations regardless of water solubility. Following a 90 minute equilibration at room temperature and humidity, the in vitro skin model was exposed to various skin moisturizers for 60 minutes. Following exposure, the moisturizers were removed and skin hydration was immediately evaluated by measuring the electrical impedance of the tissue surface (DPM 9003 Nova Meter, Nova Technologies). Total RNA was extracted from the epidermis and changes in the expression of genes modulating barrier function were evaluated. Analysis of skin hydration by electrical impedance demonstrated significant 2-5 fold differences between moisturizer treated tissues and untreated or PBS treated tissues. Furthermore, although all moisturizers demonstrated increased epidermal hydration, significant differences were observed among the various moisturizers tested. Altogether, assessment of skin hydration following treatment with topically applied moisturizers in the EpiDermFT in vitro human skin model is a valuable in vitro method for use in product development and claims substantiation studies.
Poster Session III: Saturday Morning, 4/29, 10:15 AM – 12:15 PM
Abstract 710 Use of Mass Spectrometry Imaging and a Full Thickness 3D Skin Equivalent for Evaluation of Percutaneous Absorption
M Bachelor1, E Seeley2, C Walsh2, A Armento1 and H Goodman2
1MatTek Corporation, Ashland, MA and 2Protea Biosciences, Inc, Morgantown, WV
Human skin equivalents are a useful tool for the evaluation of percutaneous permeation and absorption of topical actives. Standard evaluation typically involves determining quantities of active that (1) traverse the skin equivalent into a receiver solution below the tissue over a given period of time (2) remain on the apical surface and (3) are retained within the tissue. Incorporating the use of mass spectrometry imaging (MSI) into this type of study allows for localization of endogenous and exogenous compounds along with their relative concentrations in thin tissue sections. Utilization of MSI technology has the added benefit of determining exactly how much of a dosed compound reaches its target location. In this study, retinoic acid was applied topically to EpiDermFT, a full thickness skin equivalent, to evaluate permeation and localization within the epidermal and dermal layers of the tissue model. Twelve-micron tissue sections were coated with a dihydroxybenzoic acid matrix using a SunCollect robotic reagent sprayer and imaged in reflectron positive ion mode using a MALDI TOF/TOF MS. Significant differences in permeation were observed in skin equivalents treated with retinoic acid solution compared to a commercially available retinol complex formulation. Compounds specific to either the epidermal or dermal layer of the skin equivalent were also detected by MSI following a single 24 hour treatment. In addition, unique lipid species were modulated in tissues treated with a retinol formulation but not unformulated retinoic acid. As the EpiDermFT tissue model has previously demonstrated drug metabolizing capabilities, both technologies can be exploited to gain insight not only into the localization of applied actives, but also drug metabolites and other biomolecules following treatment in pursuit of cosmetic and pharmaceutical drug development.