Development of In Vitro models for investigating human fibroblast and keratinocyte migratory behaviours into adjacent...

To facilitate the clinical translation of engineered tissues, improved insight into cell behaviour at graft-host interfaces is essential. Due to the constraints of animal models in resolving detailed cell migration, this study developed in vitro systems to examine the migratory responses of human dermal fibroblasts (HDFs) and immortalised human keratinocytes (HaCaT) at interfaces between fibrin clots and different culture environments. HDFs exhibited spindle-like morphology and stochastic migration on solid substrates, including culture plastic and porous scaffolds. Within the pores of nickel and cellulosic scaffolds, HDFs coordinated their movements to form cellular bridges and dense multicellular membranes. Across all the invstigated conditions, HDFs demonstrated pronounced sprouting into surrounding fibrin, forming branched, interconnected networks. In contrast, HaCaTs showed limited migration, forming compact colonies on solid substrates and within fibrin. Detailed imaging revealed that HDF migration in fibrin was regulated by both cell-cell and cell-extracellular matrix interactions, while additional cell-substrate interactions influenced behaviour in porous environments. Co-culture studies further indicated that HDF migration into fibrin was modulated by neighbouring HDFs or HaCaTs, whereas HaCaT cell dynamics remained largely unaffected. These findings provide mechanistic insight into cell-specific migration and might inform the rational design of tissue-engineered constructs and implantation strategies.