Development of a 3D bioprinted human skin model for predictive toxicology

Three-dimensional (3D) cultures represent an advanced approach for mimicking the architecture and cellular complexity of human tissues, providing a valuable alternative to conventional two-dimensional models. In particular, 3D bioprinting enables the generation of precise, standardized and biomimetic tissue constructs, with controlled spatial organization. The aim of the study was to design a novel 3D bioprinted full-thickness human skin model 3D protocol able to replicate human skin layers. The model is based on a high-concentration type I collagen bioink combined with dermal fibroblasts and keratinocytes, in which the use of dense collagen I enhances the mechanical properties and biomimetic features of the construct, providing dermal and epidermal contributions, and a physiologically relevant extracellular matrix. The skin like tissue (SLT) obtained was evaluated using established irritant and sensitizer controls, demonstrating its ability to respond to chemically induced stimuli without implying quantitative performance comparisons. Overall, this 3D skin model provides a biologically relevant and reproducible platform for early-stage testing of topically applied compounds, with potential applications in cosmetic safety assessment, drug screening, and alternative in vitro testing strategies.