Characterization of MgO/CaO hybrid nanorods as an enhanced inorganic carrier of 5-Fluorouracil drug; loading, release, and cytotoxicity studies

Synthetic MgO/CaO hybrid nanorods (Mg/Ca_(NRs)) was characterized as a carrier for a 5-Fluorouracil drug. The structure has significant loading capacity (342.8 mg/g) and the loading capacity can be controlled based on the experimental factors. The loading process follows the Pseudo-first order kinetics (R² > 0.99) and classic Langmuir equilibrium (R² > 0.99). This reflected monolayer, physisorption, and homogenous loading process. Based on the Monolayer model of one energy, the structure exhibits 295.7 mg/g as loading sites density, and each site is loaded with dimer 5-Fu molecules (> 1 molecule) reflecting multi-molecular loading of the drug molecules. The estimated loading energy (10.09 kJ/mol) is within the energy limits of the physical processes as Van-der Waals forces, hydrogen bonding, and dipole bonding forces. The Mg/Ca_(NRs) structure exhibits slow and long release profiles that continued up to 100 h and 62 h within the gastric and intestinal fluids, respectively. The release behavior follows the Higuchi release kinetics which demonstrates the dominance of the diffusion processes as the occurred release mechanism. The cytotoxicity investigation reflects safe and biocompatible properties of Mg/Ca_(NRs) on the colorectal fibroblast cells (CCD-18Co) (300 µg mL^{− 1}; cell viability 83.6%). Additionally, it displays significant cytotoxicity effect on the HCT-116 cancer cells (300 µg mL^{− 1}; cell-viability 60.4%) which can induce the impact of the loaded drug as cancer therapy. This cytotoxic impact was enhanced strongly for the 5-Fu loaded Mg/Ca_(NRs) (300 µg mL^{− 1}; cell-viability 9.6%) as compared to free 5-Fu (cell-viability 34%).