Cell-laden 3D bioprinted hydrogels for wound healing: cellular mechanism, bioprinting determinants and translational perspectives.

Cell-laden three-dimensional (3D) bioprinted hydrogels have emerged as a promising technique for enhanced wound healing by integrating biomaterials, living cells, and precise fabrication technology. Chronic wounds that persist for an extended period of time, especially when pathologically affected by diseases like diabetes, can pose a serious threat to patients' health. Conventional dressing materials typically fail to provide adequate mechanical strength, drug release control, and complete tissue regeneration. In contrast, 3D bioprinting can allow for the selective deposition of cells into the extracellular matrix-mimetic hydrogels, making it possible to construct biomimetic scaffolds for tissue regeneration. This review provides a clear overview of how key cellular components such as mesenchymal stem cells (MSCs), adipose-derived stem cells (ADSCs), fibroblasts, and multicellular systems contribute to important wound healing processes like immunomodulation, angiogenesis, cell proliferation, and re-epithelialization. It also explores how bioprinting factors, including bioink rheology, cross-linking methods, and processing conditions, influence printability, the structural stability of scaffolds, and cell survival. The close relationship between scaffold design and how cells respond is emphasized as a key factor in determining how effective the treatment will be. Although pre-clinical studies have shown promising results, bringing this research into real-world clinical use remains challenging due to issues like lack of standardization, difficulties in scaling up, regulatory hurdles, and high costs.