IRMOF-8-encapsulated curcumin as a biocompatible, sustained-release nano-preparation

Metal-organic frameworks (MOFs) are porous coordination polymers formed by metal ions and organic ligands through coordination bonds. In drug delivery applications, MOFs can impart sustained release, targeting, protection of easily degradable drugs, and improved drug solubility. Isoreticular metal-organic framework-8 (IRMOF-8) is a mesoporous MOF with a network topology bridged in the form of an octahedral cluster. Compared with other materials, it has the remarkable advantages of high porosity and a regular pore structure. Curcumin (CUR) is a diketone compound with potent antitumor effects. Due to its poor solubility and stability, its clinical application is limited. Therefore, we used IRMOF-8 as a carrier for the encapsulation of CUR to overcome the shortcomings of CUR itself and expand its clinical application. In this study, IRMOF-8 was synthesized through direct mixing of triethylamine (TEA). In vitro cell experiments demonstrated the biocompatibility of IRMOF-8. Using the solvent adsorption method, CUR was encapsulated by IRMOF-8 with a drug loading content of 58.86 ± 0.98 wt%. In vitro drug release experiments performed at pH levels of 7.2 and 5.5 showed that the preparation had a sustained-release effect over 7 days. Through cytotoxicity experiments after drug loading, it was found that CUR@IRMOF-8 had a strong cytotoxic effect on HepG2 cells, promoted cell apoptosis and intracellular uptake, decreased mitochondrial membrane potential, and increased reactive oxygen species. Hence, CUR@IRMOF-8 is expected to become an excellent sustained-release preparation for potential applications in tumor treatment.