Understanding the effect of vitamin B6 and PEG functionalization on improving the performance of carbon nanotubes in temozolomide anticancer drug transportation

Density functional theory (DFT) and molecular dynamics (MD) simulation are employed to explore the efficiency of functionalized carbon nanotubes with polyethylene glycol (CNT-PEG) in temozolomide (TMZ) delivery. The obtained results from DFT calculations reveal that the interaction of the TMZ molecule with a nanocarrier has a physical nature. It is found that pi - pi stacking interaction between the drug and carbon nanotube rings has a principal role in the stability of the TMZ on the carrier surface. Moreover, the hydrogen bond formed between the drug molecule and PEG group leads to greater stability in the resulting complexes. The electronic structure analysis of TMZ shows that the structure of the drug molecule does not change considerably during the adsorption process. Also, it is observed that during the complexation, the charge is transferred from the carrier to drug. Moreover, MD simulation is performed to study the dynamics and diffusion of the drug molecule. The obtained results indicated that there are strong interactions between TMZ molecules and CNT-PEG in a biological environment. These interactions become stronger with the presence of vitamin B6. Therefore, it seems vitamin B6 can be used to improve the adsorption behavior of the TMZ drug molecule.