Cyclodextrin metal–organic framework@SiO2 nanocomposites for poorly soluble drug loading and release

Abstract

The development of non-toxic drug carrier materials with high loading capacity, sustained release properties, stability, and biocompatibility holds significant medical value and potential for loading and releasing poorly soluble drugs. In this study, we synthesized a biocompatible, non-toxic, environmentally friendly CD-MOF porous material with high specific surface area and tunable structure. By incorporating SiO₂ to enhance the stability of MOF materials, the synthesized CD-MOF@SiO₂ material shows promising applications in drug delivery. The obtained CD-MOF@SiO₂ nanocomposite was utilized as a carrier for the poorly soluble drug, folic acid. Characterization of the drug-loaded composite before and after drug loading was performed using scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, N₂ adsorption–desorption, and X-ray diffraction analyses, showing improved stability as indicated by thermogravimetric analysis and derivative thermogravimetry data. UV spectrophotometry was used to investigate the loading and sustained release of folic acid under different conditions in PBS buffer, demonstrating that the well-structured CD-MOF@SiO₂ material exhibits high drug loading and controllable release properties. The CD-MOF@SiO₂ achieved a high drug loading efficiency (166.78%) and encapsulation rate (83.39%) for folic acid, leading to a significant increase in apparent solubility from 1.6 μg mL⁻¹ in its free form to 21.74 mg mL⁻¹, a 13 588-fold expansion. This work presents a novel, efficient, and highly valuable approach for the development of carrier materials for loading and releasing poorly soluble drugs.