Influence of ligand distribution on uptake efficiency.

Cellular uptake is a crucial process in nanomedicine and drug-delivery; however, the factors that affect its efficiency/speed are not well understood. We report computer simulations on passive uptake via receptor-mediated endocytosis of nanoparticle coated with ligands. In particular, we study how the distribution of ligands on the nanoparticle surface influences the uptake rate. The speed of membrane wrapping and uptake was found to be the fastest for nanoparticles with homogeneous ligand distributions, where ligands are spread evenly on the surface. We show that the diffusion of the ligands on the nanoparticle can hinder its uptake, since upon the interaction with the membrane the ligand distribution becomes extremely inhomogeneous, with a large ligand-free patch. When the ligand-free-area was more than 20% of the surface, we did not observe uptake within the scale of our simulations.