Novel γ-cyclodextrin-based metal–organic frameworks for the effective encapsulation of oregano essential oil and controlled release

Abstract

γ-cyclodextrin-based metal–organic frameworks (γ-CD-MOFs) have considerable potential as a novel porous material with biocompatible properties for use as carrier-based drug delivery. Oregano essential oil (OEO) has been remarkably applied in the food and medical field. Herein, γ-CD-MOFs were prepared in 88% yield by a modified vapor diffusion method for encapsulating liquid OEO. At optimal encapsulation conditions (120 °C for 1 h), encapsulation efficiency and loading capacity reached 27.32% and 8.43%, respectively. Moreover, crystal structure characterization revealed that encapsulation of OEO did not change the crystal state of γ-CD-MOFs. Thus, based on a thorough characterization of prepared inclusion complexes, it was demonstrated that OEO was successfully encapsulated with increased thermal stability. Moreover, γ-CD-MOFs exhibited outstanding release control in vitro experiments. Collectively, the results indicated that γ-CD-MOFs can be used as an effective carrier to deliver OEO.