Simple cellular potts model of scratch assays on healthy and keloid fibroblasts driven by contact inhibition of locomotion

In this study, we propose and validate a simple agent-based model to study cell-cell interactions and cell migration during in vitro scratch assays in the context of cutaneous fibrosis (keloid). For model parametrization, we collect data from in vitro experiments performed with healthy or keloid fibroblasts treated (or not) with type 1 or 2 macrophages secretome to mimic specific in vivo environments. All experiments were performed with mitomycin to inhibit cell proliferation, and subsequently isolate the sole contribution of migration to wound filling over time. The scratch assays are modeled within the cellular Potts model framework. The calibration process, via Levenberg-Maquart algorithm, gives a mean error of 4.53 ± 0.77% across the four modalities (healthy, control, M1 and M2 secretum) and the evaluation dataset gives a mean error of 10.55 ± 0.77%. With the help of this model, we test whether the hypothesis of contact inhibition of locomotion (CIL) can explain the movement of keloid fibroblasts. The simulation results and their comparison with the experimental data suggest that CIL might not characterize the movement of keloid fibroblasts, which is in contrast to the importance of CIL for the movement of healthy fibroblasts.