Fusion and fission pathways of vesicles from amphiphilic triblock copolymers: a dissipative particle dynamics simulation study.

Dissipative particle dynamics (DPD) simulations are employed to study the fusion and fission dynamics of polymeric vesicles formed from amphiphilic triblock copolymers. The amphiphilic molecule is built from two hydrophilic blocks and a hydrophobic middle block. Two different pathways for both fusion and fission processes of two-component vesicles with polymer-based symmetric membranes have been found in the simulations. For each of the pathways, the conditions required to obtain complete fusion and fission have been investigated. Moreover, the fission process of single-component vesicles with polymer-based asymmetric membranes has also been studied in the simulations. Interestingly, the daughter vesicles have the same composition as the parent vesicle and only one fission pathway has been observed. Furthermore, the fusion and fission pathways have been compared and distinct vesicle recycling pathways have been suggested according to the results from the simulations. These findings may be helpful in explaining the fusion and fission dynamics of vesicles and understanding the general principle of membranes.