Keratinocyte primary cells are fundamental components of the epidermis, playing a crucial role in forming the skin barrier and mediating various skin functions. Isolating and culturing these cells from human skin biopsies have significantly advanced dermatological research and therapeutic applications.​

Isolation and Culture Techniques

Establishing primary cultures of human keratinocytes typically involves enzymatic digestion of skin biopsies to obtain viable cells. Recent studies have optimized culture conditions by supplementing media with epidermal growth factor (EGF), enhancing cell proliferation and differentiation. For instance, research has demonstrated that human skin keratinocyte primary cultures can be efficiently established from skin biopsies using media containing EGF, although further optimization is necessary to accelerate the procedure and obtain cultures in less time. ​

Immortalized Keratinocyte Cell Lines

While primary keratinocytes are invaluable for research, their limited lifespan in culture poses challenges. To address this, scientists have developed immortalized keratinocyte cell lines, such as N/TERT, by introducing genes like SV40 large T antigen and human telomerase reverse transcriptase (hTERT). These cell lines provide an unlimited, biologically relevant cell source for in vitro studies on epidermal biology, inflammatory skin diseases, and therapeutic testing. 

Functional Characteristics

Primary keratinocytes exhibit characteristics essential for studying skin physiology, including the formation of a functional barrier, differentiation kinetics, and specific protein expression profiles. Immortalized keratinocyte cell lines have been shown to retain many of these characteristics, such as barrier formation and differentiation kinetics, making them suitable for various research applications. 

Applications in Disease Modeling

Keratinocyte cultures, both primary and immortalized, serve as valuable models for studying skin diseases, including psoriasis, eczema, and cancer. They facilitate the investigation of disease mechanisms, drug testing, and the development of therapeutic interventions. For example, research has utilized keratinocyte cell lines to study the pathogenesis of inflammatory skin diseases and to evaluate potential therapeutic agents.