DermaCult Keratinocyte Expansion Medium: A Serum- and BPE-Free Medium Supporting Long-Term Feeder-Free Expansion of Primary Human Epidermal and Pluripotent Stem Cell-Derived Keratinocytes

The study developed DermaCult™ Keratinocyte Expansion Medium (KEM), a serum- and bovine pituitary extract-free medium that supports long-term growth of Human Epidermal Keratinocytes (HEKs) beyond the typical 15 - 30 population doublings (PDs), while maintaining their differentiation potential. The medium supported 50 - 70 PDs for adult-derived HEKs (HEKa) and over 70 PDs for neonatal-derived HEKs (HEKn) before cell senescence. HEKs cultured in DermaCult™ KEM maintained a cobblestone morphology, expressed basal cell markers, and were devoid of suprabasal marker KRT10. In air liquid interface culture, HEKs generated a stratified epithelium with the appropriate cellular architecture and expression of basal and suprabasal markers comparable to their in vivo counterparts. Keratinocytes obtained from human pluripotent stem cell-derived hair-bearing skin organoids and expanded in DermaCult™ KEM resembled those generated from primary HEKs, expressed basal keratinocyte markers, and sustained over 50 PDs before senescence.