Preparation of curcumol-loaded magnetic metal-organic framework using supercritical solution impregnation process

Abstract

A metal-organic frameworks (MOFs)-based drug delivery system was prepared by supercritical solution impregnation (SSI) technology. Firstly, core-shell structured Fe3O4@UiO-66 composite was synthesized by in situ growth of MOFs layers on the surface of carboxy-functionalized Fe3O4. The composite exhibited superparamagnetic properties with a magnetization saturation of 5.51 emu/g, allowing magnetic targeting and MR imaging along with effective drug loading and controlled release. A hydrophobic anti-cancer drug, curcumol (CUR) was encapsulated into the synthesized composite using the SSI process and ethanol impregnation. The effects of impregnating solvent, impregnation time, impregnation temperature and impregnation pressure on the drug loading content were investigated. In SSI process, the drug load reached impregnation equilibrium within 2 h. In the range of pressure 10–20 MPa and temperature 40–60 °C, the drug loading content was varied from 1.09 wt% to 5.72 wt% by adjusting the impregnation conditions. The optimal impregnation conditions were 50 °C and 20 MPa. SSI was more efficient and faster compared to conventional ethanol impregnation, and the final product can be obtained without further purification. In in vitro drug release experiment, Fe3O4@UiO-66 exhibited a sustained controlled drug release for up to 36 h. Overall, SSI technology proves to be a promising strategy to maximize the drug loading capacity of Fe3O4@UiO-66.