In vitro modelling of extracellular matrix changes during skin aging: from static 2D to 3D dynamic microphysiological systems

Skin aging results from a combination of intrinsic factors and exogenous stimuli, leading to changes in the structure and components of the extracellular matrix (including the skin basement membrane), which directly influence the aging process. In vitro models are powerful tools for exploring skin aging and overcoming inter-species differences and ethical issues associated with animal models, thus demonstrating powerful potential in skin aging research and anti-aging drug development. In this review, the advantages and disadvantages of in vitro models are discussed, including 2D monolayer models, 3D static reconstructed human skin models, 3D bioprinting models, organoid models, and Skin-on-Chip models for studying skin aging and anti-aging drug development. Finally, concepts and perspectives for the next-generation skin aging models are proposed. These models are expected to provide innovative tools for investigating the mechanisms of skin aging in depth, as well as skin aging repair and prevention.