New mechanisms of vesicles migration.

In multicellular organisms, both health and disease are defined by means of communication patterns involving the component cells. Despite the intricate networks of soluble mediators, cells are also programed to exchange complex messages pre-assembled as multimolecular cargo of membranous structures known as extracellular vesicles (EVs). Several biogenetic pathways produce EVs with different properties able to orchestrate neighboring cell reactions or to establish an environment ripe for spreading tumor cells. Such an effect is in fact an extension of similar physiological roles played by exosomes in guiding cell migration under nontumoral tissue remodeling and organogenesis. We start with a biological thought experiment equivalent to Bénard's experiment, involving a fluid layer of EVs adherent to an extracellular matrix, in a haptotactic gradient, then, we build and present the first Lorenz model for EVs migration. Using Galerkin's method of reducing a system of partial differential equations to a system of ordinary differential equations, a biological Lorenz system is developed. Such a physical frame distributing individual molecular or exosomal type cell-guiding cues in the extracellular matrix space could serve as a guide for tissue neoformation of the budding pattern in nontumoral or tumoral instances.