Modes of adhesion of spherocylindrical nanoparticles to tensionless lipid bilayers

The adhesion modes and endocytosis pathway of spherocylindrical nanoparticles (NPs) are investigated numerically using molecular dynamics simulations of a coarse-grained implicit-solvent model. The investigation is performed systematically with respect to the adhesion energy density xi, NP's diameter D, and NP's aspect ratio alpha. At weak xi, the NP adheres to the membrane through a parallel mode, i.e., its principal axis is parallel to the membrane. However, for relatively large xi, the NP adheres through a perpendicular mode, i.e., the NP is invaginated, such as its principal axis is nearly perpendicular to the membrane. The value of xi at the transition from the parallel to the perpendicular mode decreases with increasing the D or alpha, in agreement with theoretical arguments based on the Helfrich Hamiltonian. As xi is further increased, the NP undergoes endocytosis, with the value of xi at the endocytosis threshold that is independent of the aspect ratio but decreases with increasing D. The kinetics of endocytosis depends strongly on xi and D. While for low values of D, the NP first rotates to a parallel orientation then to a perpendicular orientation. At high values of xi or D, the NP is endocytosed while in the parallel orientation. Published under an exclusive license by AIP Publishing.

Automated summary

The adhesion modes and endocytosis pathway of spherocylindrical nanoparticles were investigated using molecular dynamics simulations. The study found that the adhesion mode changes from parallel to perpendicular as the adhesion energy increases, and the endocytosis process is influenced by the adhesion energy and nanoparticle parameters.