The state of art in the prediction of mechanism and modeling of the processes of surface functionalized carbon nanotubes into the membrane cell

Abstract

Carbon nanotubes (CNTs), due to their unique properties, are attracting increasing attention in biomedicine applications. Chemically functionalized CNTs (fCNTs) are being developed for therapeutic and diagnostic applications, and it is important to understand how they penetrate living cells. By examining the behavior of CNT around the membrane cell, it is possible to find which types of interactions are involved in the insertion mechanism, as well as what kinds of functional groups the nanotube surface has to offer. Here, classical molecular dynamics (MD) simulations are used to investigate the interactions of CNT and fCNT with a cell membrane model. The MD simulation results showed that in all systems during the simulation, the nanotubes with a “nanoneedle” mechanism spontaneously move from the water bulk toward the membrane center. The type of functional group on the nanotube can strongly affect the “permeation” phase. The interaction of fCNTs with membrane head groups is enhanced due to the presence of functional groups on their surface. The van der Waals interaction energy for CNT, NH2-CNT, and COOH-CNT systems reached ∼−1059, −1180, and −1255 kJ/mol, respectively, which indicates the COOH-CNT has a stronger interaction with the lipid bilayer than the CNT and NH2-CNT. It is found that the location of functional groups can be affected the diffusion of CNT into the membrane.