3D bioprinting of skin equivalents: Towards functional wound healing models.

Developing physiologically relevant human skin models remains a critical challenge in regenerative medicine and disease modelling, particularly for chronic wounds that involve persistent inflammation and vascular dysfunction. Recent advances in 3D bioprinting provide improved spatial organisation and reproducibility compared with other engineering strategies, enabling the fabrication of skin equivalents with increasing structural and cellular complexity. Nevertheless, most current models do not capture the dynamic crosstalk between immune and vascular systems, which is central to wound healing and tissue homoeostasis. This review surveys recent progress in engineering skin models that incorporate immune and vascular elements, and discusses the biological and technological barriers that continue to limit their integration. We also highlight emerging strategies, including organoids, 4D bioprinting, and computational approaches, that may enable next-generation platforms. By more accurately modelling the wound microenvironment, such advances could accelerate translation from laboratory innovation to clinical application.