A Phase-field model of cell motility in biodegradable hydrogel scaffolds for tissue engineering applications

Tissue engineering aims at producing in the laboratory new biological tissues by combining cells, scaffold materials, and biochemistry. Recent successes in the field are promising, but sustainability and reproducibility issues still limit the large-scale applications of this technique. The present work addresses the development of a computational model that describes cell motility in biodegradable hydrogel scaffolds. The goal is to support the understanding and the control of the first stage of tissue formation, when cells seeded into the scaffold congregate to form clusters, necessary precursors of tissue blocks. Cellular migration is treated as an advective/diffusive process modeled via the phase-field approach. The chemo-biological mechanisms incorporated in the modeling framework are: (i) the natural degradation of the hydrogel; (ii) chemotaxis induced by cell-cell signaling pathways; (iii) nutrient diffusion through the construct and its consumption by cells. Each cell initially moves following a random path, subsequently switching to a directed chemically-driven motion when the presence of other cells is sensed in its neighborhood. Numerical results highlight the role of the interplay between nutrient availability in the construct, chemoattractant production, scaffold degradation and cell motility, showing that the proposed model could pave the way towards efficient computationally-aided tools for the optimization of neotissue mass production.