LAUSR

Significance It is known that thin elastic nanofibers or flexible filaments could play essential roles in morphological evolution of cells or cellular compartments, thereby influencing various cellular activities. However, a fundamental understanding of the underlying biophysical mechanisms remains elusive. Here, we consider the model system of a flexible filament encapsulated in a vesicle and reveal how the elastic interaction between the filament and vesicle leads to various experimentally observed filament–vesicle morphologies. Our results, which include a set of phase diagrams on vesicle morphologies and symmetry transitions depending on the relative stiffness and size of the filament to vesicle, provide a theoretical basis to understand filament-controlled cell shaping and to help guide the design of artificial cells and biohybrid microrobots.