Applications of Zeolitic Imidazolate Frameworks in Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a cross-sectional, non-ionizing and non-invasive imaging method for diagnosing many diseases. MRI contrast agents are used to improve MRI sensitivity and the images contrast. Zeolitic imidazolate frameworks (ZIFs) are microporous materials with large surface area, pH-responsiveness and good thermal and chemical stability. Due to their unique physicochemical properties, ZIFs have the potential to be used in MRI. This study aimed to review the applications of ZIFs in MRI. ZIFs-based nanomaterials, due to their porous structure, good stability under physiological conditions and long circulation half-life, can be used as the support for MRI nano contrast agents. Besides, their high loading capacity and porosity allow anticancer drug loading. ZIFs can be modified with ligands to release the drug in the acidic tumor microenvironment. Simultaneous loading of the MRI nano contrast agents and chemotherapy drugs to ZIFs produces nanotheranostics, which allows for cancer treatment under MRI monitoring. Additionally, incorporating the photosensitizers into the structure of the nanotheranostic provides multifunctional probes for MRI and photothermal chemotherapy. Among different types of ZIFs, ZIF-۸, ZIF-۶۷, ZIF-۹۰, and ZIF-۷ have been used for the in vitro studies and animal MRI and drug delivery. ZIF-۸ is the most widely used ZIF in MRI because of the presence of zinc and zinc ions in its structure, which provides good biocompatibility, and also its large surface area to load the contrast agent and high stability. As a conclusion, the use of ZIFs in MRI can provide advances in diagnostic imaging and image-guided therapy.

کلیدواژه ها:

Zeolitic imidazolate frameworks ، Magnetic resonance imaging ، Contrast agent ، Nanotheranostics