Delivery of Cisplatin Anti-cancer Drug by Si-Decorated Al24N24 Nanocage: DFT Evaluation of Electronic and Structural Features

We investigated the potential application of Al₂₄N₂₄ nanocage (AlN-NC) as a drug delivery system for the anticancer drug cisplatin (CP) through density functional theory computations. Results indicate that CP drug very weakly interacts with the AlN-NC with the adsorption energy (AD-E) of around − 6.8 kcal/mol. This makes the AlN-NC inappropriate for the drug delivery. To overcome this problem, the AlN-NC has been decorated with Si impurity atoms. Decoration of the Si into the structure of the AlN-NC increased the AD-E of CP to − 33.4 kcal/mol. Based on the analysis of the partial density of states, the Si atom considerably contributed to the generation of the virtual orbitals of the Si-decorated AlN-NC (Si@AlN-NC), which showed that this atom was suitable for nucleophilic attack compared to the Al atoms. Finally, the adsorption performance and capacity of CP increased after decorating the Si, which made the AlN-NC more suitable for drug delivery. A mechanism of drug release was introduced into the cancerous tissues, which showed that, in cancerous cells with low pH, CP was significantly protonated, which led to the separation of CP from the surface of the Si@AlN-NC. The reaction nature of CP with the AlN-NC changed from covalent bonding in the natural environment to H-bonding in the acidic cancer cells.