Engineering a Pigmented Skin Equivalent That Is Responsive to External Stimuli

Area of Science:

• Dermatology
• In vitro models
• Skin biology

Background:

• Human skin equivalents (HSEs) are crucial preclinical tools in dermatological research.
• Existing HSE models often lack crucial cell types like melanocytes, limiting their ability to accurately simulate skin's response to stressors.
• This deficiency hinders the study of UV radiation effects and melanin's protective role.

Purpose of the Study:

• To develop an advanced full-thickness skin platform incorporating human melanocytes.
• To create a more physiologically relevant in vitro model for studying skin pigmentation and UV protection.
• To establish a robust platform for testing cosmetic ingredients and understanding cellular responses to environmental stressors.

Main Methods:

• Adaptation of a novel full-thickness skin platform.
• Incorporation of human melanocytes to produce and transfer melanin to keratinocytes.
• Utilisation of Alvetex® scaffold and endogenous extracellular matrix (ECM) secretion by fibroblasts for dermal foundation.
• Observation of melanin transfer and supranuclear cap formation.

Main Results:

• Successful integration of melanocytes, leading to melanin production and transfer to keratinocytes.
• Formation of apical supranuclear protective caps, mimicking physiological conditions.
• Demonstration of the model's responsiveness to melanogenesis regulation (upregulation and downregulation).
• Validation of the scaffold and fibroblast-secreted ECM in supporting pigmented epidermis and cap formation.

Conclusions:

• The developed HSE model accurately replicates key aspects of skin pigmentation and UV protection.
• This advanced model offers a superior in vitro tool for preclinical research, cosmetic active testing, and studying cellular responses to environmental factors.
• The inclusion of melanocytes and a robust dermal foundation enhances the physiological relevance of HSEs for dermatological applications.