Theoretical study on the use of carbon nanotube as carrier for targeted drug delivery system

Abstract

The objective of this research is to understand the behavior of drug delivery system (DDS) based on carbon nanomaterial at molecular level. Firstly, graphene sheets were selected as mimic models to study the binding interactions between anti-cancer drug and carbon nanomaterials by density functional theory (DFT) and density functional theory tight binding (DFTB). As suggested by the calculations, the drug-graphene bindings were mainly governed by π-π interactions. The loading capacity of gemcitabine drug inside single-walled carbon nanotube (SWCNT) cavity was subsequently studied by molecular dynamics (MD). The results showed that more than one anti-cancer drug can be encapsulated inside the tube cavity through the partial π-π stacking interaction between the aromatic cytosine ring of gemcitabine and the inner surface of the SWCNT together with the interactions among gemcitabine molecules themselves. Then, the effect of the length of chitosan (CS), an epidermal growth factor (EGF)-SWCNT linker, has been explored by replica exchange MD simulation. The appropriate chitosan length with a minimum mass ratio of chitosan per SWCNT of 1.26 can preserve EGF conformation and prevent the steric effect from SWCNT towards binding interface of EGF and its receptor, epidermal growth factor receptor (EGFR). Importantly, the EGF of EGF-CS-SWCNT had similar binding affinity with EGFR respect to the EGF alone as indicated from MD results. Taken together, these basic details of DDS behavior are helpful for the design and development of efficient device for cancer therapy in the near future.