01738nas a2200229   4500000000100000008004100001260001500042100002200057700001700079700001400096700001600110700001600126700002300142700001900165700002300184700001800207245005200225856005200277300001400329490000600343520115900349       2023                            d  c2023-11-131 aElizabeth Footner1 aKate Firipis1 aEmily Liu1 aChris Baker1 aPeter Foley1 aRobert M. I. Kapsa1 aElena Pirogova1 aCathal O’Connell1 aAnita Quigley00aLayer-by-Layer Analysis of In Vitro Skin Models  uhttps://doi.org/10.1021/acsbiomaterials.3c00283  a5933-59520 v93 aIn vitro human skin models are evolving into versatile platforms for the study of skin biology and disorders. These models have many potential applications in the fields of drug testing and safety assessment, as well as cosmetic and new treatment development. The development of in vitro skin models that accurately mimic native human skin can reduce reliance on animal models and also allow for more precise, clinically relevant testing. Recent advances in biofabrication techniques and biomaterials have led to the creation of increasingly complex, multilayered skin models that incorporate important functional components of skin, such as the skin barrier, mechanical properties, pigmentation, vasculature, hair follicles, glands, and subcutaneous layer. This improved ability to recapitulate the functional aspects of native skin enhances the ability to model the behavior and response of native human skin, as the complex interplay of cell-to-cell and cell-to-material interactions are incorporated. In this review, we summarize the recent developments in in vitro skin models, with a focus on their applications, limitations, and future directions.