Molecular dynamics study on the configuration and arrangement of doxorubicin in carbon nanotubes

Carbon nanotubes are potential candidates for drug delivery system (DDS) design due to their capacity to internalize and control the release of molecules. In this work, single-walled carbon nanotubes (SWCNTs) are the high-capacity drug carrier under study, and doxorubicin (DOX) is the model drug. Molecular dynamics simulations were performed to investigate the configuration and arrangement of different loading amounts of DOX in SWCNTs. The results show that the orientation and arrangement of DOX molecules can be influenced by drug concentration and by the diameter of the SWCNT. If the diameter of SWCNT is relatively small and there is strong confinement (e.g., in SWCNT (10,10)), DOX molecules prefer to form a single-file helix inside the SWCNT, which suggests that the controlled loading and release of a single drug molecule can be achieved by precise manufacture of SWCNTs with specific diameters, thus overcoming the disadvantage of aggregated DOX structure in solution and reducing chemotherapy dosage.