Collective Behavior of Urease pH Clocks in Nano- and Microvesicles Controlled by Fast Ammonia Transport

The transmission of chemical signals via an extracellular solution plays a vital role in collective behavior in cellular biological systems and may be exploited in applications of lipid vesicles such as drug delivery. Here, we investigated chemical communication in synthetic micro-and nanovesicles containing urease in a solution of urea and acid. We combined experiments with simulations to demonstrate that the fast transport of ammonia to the external solution governs the pH-time profile and synchronizes the timing of the pH clock reaction in a heterogeneous population of vesicles. This study shows how the rate of production and emission of a small basic product controls pH changes in active vesicles with a distribution of sizes and enzyme amounts, which may be useful in bioreactor or healthcare applications.

Automated summary

The transmission of chemical signals through extracellular solution is important in cellular biological systems and lipid vesicles applications. This study investigates chemical communication in synthetic micro-and nanovesicles containing urease in a solution of urea and acid. Through experiments and simulations, it is demonstrated that the fast transport of ammonia to the external solution controls the pH-time profile and synchronizes the timing of the pH clock reaction in a heterogeneous population of vesicles. This research shows how the rate of production and emission of a small basic product controls pH changes in active vesicles with different sizes and enzyme amounts, which may have applications in bioreactors or healthcare.