Molecular dynamics study of functionalized carbon nanotube loaded with multiple doxorubicin targeted to folate...

Two novel targeted drug delivery systems (DDSs) were designed: folate (FOL) conjugated (9, 9) carbon nanotube (CNT) loaded with 20 doxorubicin (DOX) molecules (FOL-CNT/20DOX) and folate (FOL) conjugated carboxylated (9, 9) CNT (COOH-CNT) loaded with 24 doxorubicin (DOX) molecules (FOL-COOH-CNT/24DOX). The targeted property to folate receptor α (FRα) was calculated using molecular dynamics (MD) calculations. The structures of the FRα/FOL-CNT/20DOX and FRα/FOL-COOH-CNT/24DOX complexes were analyzed in detail. Radial distribution functions were calculated to analyze the distribution of DOX molecules around the CNTs in the complexes. The variation of representative distances and angles between novel DDSs and FRα, number of hydrogen bonds, and secondary structures of FRα during the MD simulations were studied to analyze the dynamic properties of the novel DDSs targeted to FRα. We further analyzed the root mean square displacement and root mean square fluctuation in detail. The results indicate that the two novel DDSs were very stable and well targeted with FRα, and FOL-COOH-CNT/24DOX had better targeting and stability than FOL-CNT/20DOX. This study is expected to provide insights for the design of efficient nano drug delivery systems with good FRα targeting and controllable drug loading dosage.