During embryonic development and various healing processes, tissues consist of cells migrating collectively. Researchers have made strides toward fully explaining this complex phenomenon. Recent insights highlight the pivotal role of internal dissipation over traditional substrate friction mechanisms.
A remarkable study, conducted by a team led by J. Rozman, K. Chaithanya, and J.M. Yeomans, investigates how internal viscous dissipation enables sustained flows within epithelial tissues. This work extends upon existing vertex models used for simulating tissue dynamics, addressing limitations related to friction with underlying substrates, which prevail during early stages of development without solid support.
The team introduced modification to the established active nematic vertex model applicable to tissues, replacing the conventional substrate friction with internal dissipation. This adaptation permits cell interactions not only to drive local movements but also to contribute to long-range velocity correlations across tissues, promoting coherent flow patterns.
Supported by their simulations, the researchers demonstrated consistent achievement of coherent, unidirectional flows when internal dissipation is factored. They presented the vertex model characteristics, where sustained flows naturally emerged within channels, underscoring their findings by stating, “Internal dissipation dynamics allow the vertex model to develop channel-wide, unidirectional flows, which we do not observe in the substrate dissipation model.”
The significant result proposed by this research indicates how internal dissipation enhances the migratory efficiency of epithelial tissues. It provides insights applicable to processes such as wound healing and tissue engineering, which require well-coordinated cellular movement.
Describing the broader applications, the researchers elucidate the implications for early embryonic stages, where cells often operate without rigid supportive matrices. They assert, “This study is especially important in some early-stage embryos where cells are not supported by a substrate,” illuminating the necessity of this research.
The study not only broadens the scope of active vertex models by including viable friction dynamics for unconfined tissues, but critically connects the behaviors observed at the cell level with continuum theories of active nematics, paving new pathways for future studies on collective behaviors within tissues.
Overall, Rozman and colleagues have made meaningful contributions to our comprehension of cell migration mechanics, emphasizing the relevance of internal dissipation processes. Such insights promise improvements not only within theoretical models but also practical applications tied directly to human health outcomes during wound healing and developmental biology.