Anti-cancer chlorambucil drug delivery by Pt, au, and Ir-decorated ZnO nanotubes

The pristine ZnO nanotube (ZnONT) and the X (X = Pt, Au, and Ir)-decorated ZnONT (X@ZnONT) forms were studied as drug delivery systems (DDSs) for the anti-cancer chlorambucil (ChB) drug using DFT computations. The pure ZnONT was not ideal for the drug delivery with the adhesion energy (AE) from −5.9 to −6.8 kcal/mol. The AE increased to −29.7, −27.1, and −30.8 kcal/mol after decorating the Pt, Au, and Ir onto the ZnONT, respectively. The presence of X atoms had a significant influence on creating the virtual orbitals in X@ZnONT. Consequently, it increases the adhesion capacity which makes the nanotube more favorable for drug delivery purposes. A drug release mechanism was proposed in low-pH cancerous tissues. In this mechanism, ChB becomes significantly protonated, causing it to separate from the surface. The reaction type of ChB with ZnONT changes from a covalent bond to a hydrogen bond in the acidic cancerous cells. • Potential application of ZnO nanotube (ZnO-NT) as a chlorambucil drug carrier is studied. • Decoration of Pt, Au, and Ir improve the ZnO-NT drug delivery ability. • A drug release mechanism is proposed based on the pH. • Pt, Au, and Ir-decorated ZnO-NT are electronically sensitive to the chlorambucil drug.