Exploring the structural and electronic properties of boron nitride nanotube (BNNT) as nanocarrier for drug delivery applications: DFT approach.

Boron nitride nanotubes (BNNTs) have garnered significant interest due to their exceptional mechanical strength, chemical stability, and biocompatibility. However, their limited solubility in aqueous environments poses a major challenge for biomedical applications. In this study, we employ density functional theory (DFT) calculations to explore the impact of hydroxyl (-OH) and amine (-NH) functionalization on the structural, electronic, and solubility characteristics of BNNTs. The pristine (5,5) BNNT exhibits a bandgap of 4.46 eV, which decreases upon functionalization, indicating enhanced electronic tunability. Structural modifications, including bond length elongation and charge redistribution, further influence the nanotube's chemical reactivity and interaction with surrounding molecules. A crucial aspect of this work is the investigation of carrier solubility, which reveals a strong correlation between hydration and system stability. The Gibbs free energy of solvation becomes increasingly negative, from - 602.02 kJ/mol for BNNT4Am to - 720.18 kJ/mol for BNNT4Am-6W, suggesting enhanced solubility in aqueous environments. Stronger interactions between the functionalized BNNTs and water molecules suggest them as promising candidates for drug delivery applications. Additionally, drug interaction studies were carried out between BNNT4Am and Indole-3-Carbinol, which reflects weak electrostatic interactions and polarization effects contributing to the favorable energetics and stability of nanobiohybrid complex formation.