Ligands influence a carbon nanotube penetration through a lipid bilayer

The interactions between nanomaterials and biological membranes are important for the safe use of nanomaterials. We explore the nano-bio interface by studying the penetration of a carbon nanotube (CNT) coated with ligands through a lipid bilayer. With a dissipative particle dynamics model, the mechanism of ligands influencing nano-bio interaction is analyzed. The CNTs with different ligands are tested. The simulation shows that the increase of the total number of ligand particles decreases the capability of a CNT penetrating through a membrane. For the CNTs with the same number of ligand particles, the arrangements of their ligands determine their behaviors. The asymmetrical pattern generates an upside down phenomenon, which requires more energy to get through the membrane; the uniform distribution penetrates through a membrane with less difficulty. Decreasing the stiffness, the length of ligands or preferring hydrophobic ligands increases the penetration capability of CNTs.