Molecular dynamics insights into non-covalent functionalization of boron nitride nanotubes for doxorubicin delivery

Developing effective drug delivery systems is an ongoing challenge for the treatment of cancer, in particular, enhancing the efficacy of chemotherapeutic agents like doxorubicin. This study explores the potential of pristine and non-covalently functionalized boron nitride nanotubes (BNNTs) as carriers for doxorubicin, leveraging their chemical stability, biocompatibility, and mechanical strength. Molecular dynamics simulations were conducted to analyze the effect of adding functional groups such as chitosan, ethylene glycol, poly-L-lysine, and folic acid onto the surface of BNNTs. The impact of polymers, their chain length, and the number of functional groups on optimizing drug loading profiles was investigated. Functionalization of boron nitride has increased hydrogen bonding with water and drugs. As a result, boron nitride functionalization increases the solubility of BNNTs and enhances drug loading. Analysis of the radial distribution function shows that the non-covalent functionalization of boron nitride causes the drug to be more adsorbed on the nanotube wall. In contrast, the drug in the pristine nanotube is more trapped inside it. From van der Waals (vdW) interaction energies and free energy calculations, it was revealed that functionalization using poly-L-lysine enhanced the interactions between the carrier and doxorubicin. These findings underscore the potential of functionalized BNNTs as effective carriers for targeted cancer therapy.