Discontinuous wrapping transition of spherical nanoparticles by tensionless lipid membranes

We present a numerical study of the wrapping of spherical nanoparticles by tensionless lipid membranes using molecular dynamics simulations of a coarse-grained implicit solvent model. We found that the degree of wrapping of small nanoparticles increases continuously with the adhesion strength for nanoparticles with diameter less than or about 15 nm. In contrast, the increase in the degree of wrapping becomes discontinuous for larger nanoparticles and exhibits a clear hysteresis when upward and downward annealing scans with respect to adhesion strength are performed. The gap in the degree of wrapping increases with the increase in the diameter of nanoparticles. These results are in qualitative agreement with the mean field prediction that large nanoparticles are either unbound or completely wrapped by tensionless lipid membranes.