Lipid bilayers, which make up cell membranes, can change shape in response to external stimuli. To reproduce this behaviour in a synthetic system, Jan van Esch at Delft University of Technology in the Netherlands and his co-workers have produced a vesicle — a water-filled compartment bounded by a bilayer membrane — that forms and collapses in response to changes in pH.
The system comprises a solution containing a molecule with two 'tails', each of which can form reversible covalent bonds with another molecule. When there is a sufficiently high number of the molecules, the bonds form and the vesicles spontaneously take shape; conversely, when bonds break, the vesicles eventually collapse (pictured). The stability of the bonds is also affected by the solution's pH, with vesicles forming at a pH of more than 7, and dissociating completely when pH falls below 4.
These reversible vesicles might be useful for applications that require controlled encapsulation and delivery.
Rights and permissions
About this article
Cite this article
Vesicles form with pH shift. Nature 471, 550 (2011). https://doi.org/10.1038/471550c
Published:
Issue Date:
DOI: https://doi.org/10.1038/471550c
