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USE OF EPIDERM FULL THICKNESS (EFT) SKIN CULTURES AS AN IN VITRO MODEL FOR WOUND HEALING.

Kaluzhny1, Y., Kandárová2, H., Hayden1, P., Kubilus1, J., d’Argembeau-Thornton1, L., and Klausner1, M. 1MatTek Corporation, Ashland, MA, USA; 2MatTek In Vitro Life Science Laboratories, Bratislava, Slovakia.
Abstract

Background:  Wound healing is a natural process which involves the regeneration of epidermal and dermal tissue with expression of growth factors and inflammatory markers. The objective of this study was to evaluate the EpiDerm full thickness (EpiDerm-FT, EFT) skin culture as an in-vitro wound healing model to understand the healing process after chemical induced wounding. Methods:  A strong base, 32N KOH and 2 strong acids, conc H2SO4 and acrylic acid, were selected for making chemical wounds. The dose of chemical and exposure time required to generate a significant wound were optimized. After Inducing a wound, cultures were washed thoroughly with PBS and incubated at 37°C for 6 days. The EFT tissues were collected for histological, immunohistochemistry and western blot studies. The culture medium was collected to study the release of inflammatory markers such as Interleukin-6 (IL-6) and Interleukin-8 (IL-8). Results:  Hematoxylin and eosin staining showed significant damage to the stratum corneum and upper layers of the epidermis for 32N KOH, deeper epidermal damage for conc H2SO4 and dermal damage for acrylic acid. Western blot studies showed that the ratio of colIagen IV to β-actin was increased In the order of acrylic acid > conc H2SO4 > 32N KOH while the ratio of Ki67 to β-actin was Increased in the order of conc H2SO4 > acrylic acid > 32N KOH. Similar results were observed with immunohistochemistry studies suggesting a strong correlation between the two techniques. These data were further supported by cytokine studies which showed that the release of IL-6 and IL-8 was significantly increased (P<0.001 vs control) on day 1 and thereafter it was significantly decreased (p<0.01 vs control) for all chemicals suggesting wound healing. Conclusion:  These results strongly support that the EFT cultures could be used as an in-vitro model for studying the cutaneous wound healing process.

Keywords

Acantholysis, Basal cell proliferation, Cyclopyrimidine dimer, EFT-400, EpiDerm-FT , IL-8 release, Ki67, MMP-1 activity, Morphological analysis, Pyknotic nuclei, Skin healing , Solar stimulator, UV-induced damage, Wound healing

Materials Tested

UVA, UVB

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