A Biopsy-Sized 3D Skin Model With a Perifollicular Vascular Plexus Enables Studying Immune Cell Trafficking in the Skin

This study presents a miniaturized 3D skin-on-a-chip (3D-SoC) model, created using digital-light-processing bioprinting, that mimics the human skin's vascular network and hair follicles. The model, the size of a 6 mm punch biopsy, allows for real-time observation of immune cell interactions with endothelial cells, such as tethering, rolling, and extravasation. It captures physiological shear rates, influencing T cell trafficking, with Th1 cells showing stronger attachment than naïve T cells. The presence of an epidermis is crucial for Th1 cell migration, highlighting its role in T cell infiltration. This model advances the study of immune cell and skin vasculature interactions, offering a more anatomically and functionally complex representation of human skin.