Insights into hemihydrate nanostructure as a carrier for cisplatin chemotherapy agent: A DFT and AIMD investigation

Reducing the systemic toxicity of cisplatin remains a major challenge in cancer therapy, highlighting the need for efficient targeted drug delivery systems. This study explores the potential of hemihydrate (CaSO₄⋅0.5H₂O) nanostructure as a targeted drug delivery system for cisplatin chemotherapy agent, utilizing density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulation. Structural properties, chemical reactivity, electronic structure, optical properties, MEP surfaces, adsorption behavior, and thermal stability are studied. The results show that pristine hemihydrate crystallizes in the monoclinic I₁₂₁ space group and exhibits insulating properties with a bandgap of 5.75 eV (PBE-D3), and cisplatin demonstrates good chemical stability and moderate chemical reactivity with chemical hardness and electrophilicity index values of 1.455 and 1.234 eV, respectively. Monte Carlo simulations were performed for identifying adsorption sites, followed by DFT studies. After adsorption, a remarkably strong interaction forms between hemihydrate and cisplatin, with an adsorption energy of -12 eV and no alterations in the molecular geometry of cisplatin. Structural analysis shows a geometry rearrangement of hemihydrate to partially encapsulate the molecule, accompanied by charge transfer from hemihydrate to cisplatin. Additionally, Density of states indicate the metallic behavior of the complex and optical properties show that pristine hemihydrate exhibits low polarizibility and strong ultraviolet absorption characteristics, while the hemihydrate-cisplatin complex show vacuum-like behavior. The AIMD simulations at 300 K demonstrate the stability of the interaction under the effect of heat. These results highlight hemihydrate as a promising candidate for cisplatin delivery and provide subatomic insights into the adsorption mechanism and electronic and optical properties following drug loading.