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

The Spherical Skin Model (SSM) is a novel 3D platform designed to improve drug and cosmetic testing by balancing biological accuracy with experimental efficiency. It features a core-shell structure with human fibroblasts embedded in collagen microcarriers and an outer layer of keratinocytes, produced using droplet microfluidics for rapid and consistent creation. The model demonstrates biological relevance through the expression of key epidermal and dermal markers and effective barrier function. Its utility in compound screening is highlighted by identifying the dose-dependent effects of vitamins in reducing oxidative stress and apoptosis. The SSM offers a scalable, high-throughput compatible solution for dermatological and cosmetic research.