Investigating the effect of functionalized carbon nanotube with COOH group on the drug delivery process of doxorubicin in capillary networks around cancer tumors using molecular dynamics simulation

•Molecular dynamics method was implemented.•We investigate the influence of carbon nanotube functionalization on the transport and release mechanism of doxorubicin within the capillaries surrounding cancer tumors.•augmenting the atomic ratio of the COOH group results in a substantial increase in the maximum density of the structure,•increase in the atomic ratio of the COOH group correlates with a corresponding increase in shear stress within the structure.•Ultimately, as the COOH group atomic ratio increases, there is a notable decrease in both mean square displacement (MSD). This study investigated the interaction between functionalized carbon nanotubes and doxorubicin, a commonly used chemotherapy drug, aiming to enhance cancer therapy. Functionalizing CNTs with carboxyl (-COOH) groups aimed to improve the precision of drug delivery system, enabling more effective targeting of cancerous tumors while minimizing side effects on healthy tissues. Molecular dynamics simulations indicated that after 10 ns, the system stabilized at a potential energy of 5.676 kcal/mol and a total energy of 6.62 kcal/mol, suggesting thermodynamic equilibrium. Increasing the atomic ratio of COOH groups from 2.5% to 10% significantly raised the maximum structural density from 0.0035 atm/ų to 0.0042 atm/ų, thereby enhancing drug-loading capacity through stronger intermolecular interactions. Thermal stability improved as the maximum temperature decreased from 360.64 K to 346.08 K, indicating better heat dissipation and enhanced doxorubicin stability. Moreover, shear stress increased from 3.52 Pa to 3.79 Pa, indicating enhanced mechanical resistance. The mean squared displacement (MSD) decreased from 3.42 Ų to 3.24 Ų, and the root mean square deviation (RMSD) decreased from 1.85 Å to 1.80 Å. These reductions indicated decreased molecular mobility and increased structural stability. These findings demonstrate that functionalized CNTs enhanced drug encapsulation, stability, and controlled release, maximizing the therapeutic effects of doxorubicin while minimizing side effects. This study highlighted the potential of nanotechnology to revolutionize drug delivery systems and improve cancer treatment outcomes.