Construction of cyclodextrin-based organic frameworks with adjustable size: Enhanced the physicochemical stability and controlled release characteristics of apigenin

The poor physicochemical stability and bioavailability of apigenin were main factors that limited its application in the food industry. The γ-cyclodextrin-metal-organic frameworks (γ-CD-MOFs) were prepared using polyethylene glycol (PEG) as surfactants to solve these issues. The size of γ-CD-MOFs, ranging from nanometer to micrometer dimensions, could be controlled by using PEG with different molecular weights. The γ-CD-MOFs based on PEG 10000 (molecular weight of 10000) had a small pore size (1.58 nm) and high BET surface area (810.15 m2/g), leading to a high encapsulation efficiency (74.23%) and loading capacity (41.17%) for apigenin. Apigenin interacted with γ-CD-MOFs through van der Waals forces, hydrophobic interactions and hydrogen bonding, but did not affect the inherent crystallinity of γ-CD-MOFs. Furthermore, γ-CD-MOF-10000 protected apigenin better against UV light and temperature, resulting in better anti-cancer properties and controlled release efficiency (79.89%). This strategy of constructing γ-CD-MOFs nanocarriers with tunable size may open new possibilities for hydrophobic drug applications.