Sulfated hyaluronan‐containing artificial extracellular matrices promote proliferation of keratinocytes and melanotic phenotype of melanocytes from the outer root sheath of hair follicles

: The aim of this work was to establish improved cultivation conditions for human keratinocytes (HUKORS) and melanocytes (HUMORS) from the outer root sheath (ORS) of human hair follicles for purposes of generating an epidermal graft. To this end, the cells were cultivated on artificial extracellular matrix coatings composed of collagen (COLL) and hyaluronan (HA) with varying sulfation degrees. HUKORS and HUMORS were characterized based on their morphology and proliferation, marker gene expression, protein expression and melanin content in melanocytes. Depending on the sulfation degree, the matrices provided a favorable proliferation environment for HUKORS and improved the balance between proliferation and the exertion of melanotic phenotype (gene expression and melanin content) in HUMORS. Based on the increased gene expression of microphthalmia-associated transcription factor, as well as the downstream-affected melanotic genes premelanosome protein and tyrosinase in HUMORS cultivated on collagen matrices with high-sulfated HA, we assume that sulfated HA enhanced melanotic phenotype either by directly binding the CD44 receptor or by concentrating signaling mediators on site. Being a promising cultivation environment for both HUKORS and HUMORS, collagen matrices with sulfated HA have a potential of significantly improving the development of ORS-based epidermal grafts. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1640-1653, 2019.