Spherical Skin Model: Stratified Co-Culture of Fibroblasts and Keratinocytes on Spherical Beads Toward Compound Screening

The study introduces a novel Spherical Skin Model (SSM) that uses a stratified co-culture of fibroblasts and keratinocytes on spherical beads for high-throughput screening of cosmetic compounds and modeling skin lesions. This 3D model replicates key structural and functional features of human skin, with fibroblasts in a collagen matrix forming a dermis-like core and a keratinocyte shell mimicking the epidermis. The SSM supports cell viability, proliferation, and differentiation, showing increased expression of skin differentiation markers compared to 2D cultures. It effectively demonstrates selective permeability, allowing small molecules to pass while restricting larger ones, similar to human skin. The model was used to screen antioxidant molecules, with vitamin C showing a stronger protective effect against oxidative stress than vitamin E. The SSM offers a scalable and reproducible platform for dermatological research and compound testing, with potential applications in cosmetic drug testing and modeling cutaneous lesions.