Understanding adsorption ability of CNT (6, 6-6) and BNNT (6, 6-7) nanotubes for a novel hybrid pyrazole-indole drug, InPy-7a

Abstract

The quest for enhanced drug delivery efficacy across diverse physiological conditions has spurred the exploration of various nanomaterials, including carbon-based materials like carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs). These materials offer high surface areas conducive to increased drug loading, with considerations such as surface charge, size, shape, and biocompatibility being paramount. The hybrid drug, synthesized by combining indole derivatives with a pyrazole moiety, has shown promising cytotoxicity against various cancer cell lines. In this context, we have explored the adsorption ability of CNT (6, 6-6) and BNNT (6, 6-7) nanotubes for a novel hybrid drug, InPy-7a, using density functional theory (DFT) calculations. Our study has aimed to elucidate the adsorption mechanisms and electronic properties of InPy-7a on the surfaces of CNT (6, 6-6) and BNNT (6, 6-7). Through computational tools, we have analyzed the geometry optimization of InPy-7a onto the nanotube surfaces, evaluating molecular interactions, quantum descriptors, frontier molecular orbitals (FMO), natural bond orbitals (NBO), nuclear magnetic resonance (NMR), and molecular electrostatic potential (MEP). Our results have illuminated the underlying mechanisms by revealing unique interactions and electronic changes during complexation. Based on predicted electronic aspects and molecular interactions, the CNT@InPy-7a-S5 complex system showed greater chemical reactivity, adsorption, and stability than BNNT@InPy-7a-S6. These findings open up opportunities for additional experimental validations and offer insightful information about the possible uses of drug delivery systems based on nanotubes.