Investigation of thermodynamic and structural properties of drug delivery system based on carbon nanotubes as a carboplatin drug carrier by molecular dynamics simulations

Drug delivery is an important application of nanotechnology, in particular the targeted delivery of anticancer drugs using carbon nanotubes. To investigate the anticancer carboplatin's drug delivery system based on single-walled carbon nanotubes (SWCNTs), molecular dynamic (MD) simulations were applied to carboplatin filling inside pristine SWCNT and wrapping outside the pristine and functionalized SWCNT, and the drug in the free state. No significant difference was observed in the drug conformation in the free form in comparison to complex states with SWCNT. Situating carboplatin inside the pristine nanotube close to the end of the tube is an important option for releasing the drug. The typical motion of the drug outside the pristine SWCNT was along the end to one-third of the tube length, whereas carboxylic group on functionalized SWCNT kept the drug in the tube's centerline. In addition, our energy analysis determined that the lowest binding free energy belongs to filling carboplatin in the SWCNT, resulting from the van der Waals interactions. MD simulations in comparison to previous experimental evidence confirm that the suitable model for a platinum-based anticancer drug delivery system based on SWCNTs is the encapsulation of these drugs inside nanotubes.