Lipid-Coated MOFs: a breakthrough platform for hydrophobic drug delivery
|To develop more effective drug delivery platforms, scientists have increasingly turned to hybrid materials. In a recent study, researchers have combined the structural versatility of metal-organic frameworks (MOFs) such as Zeolitic Imidazolate Framework-8 (ZIF-8), which provide a crystalline scaffold that is both porous and pH-responsive – stable under neutral conditions but quickly degradable in acidic environments, such as those found in tumours – with the biocompatibility of lipid supramolecular assemblies such as micelles, vesicles, and liposomes.
Dr. Mary Cano-Sarabia/Prof. Daniel Maspoch (Catalan Institute of Nanoscience and Nanotechnology), Prof. Heinz Amenitsch/Prof. Paolo Falcaro (Graz University of Technology) and colleagues explored the in situ formation of ZIF-8 in the presence of two amphiphilic lipid self-assemblies – CTAB-cholesterol vesicles and DMPC-cholesterol liposomes—to yield hybrid lipid/ZIF-8 biocomposites. Using different analytical techniques, including Small Angle X-Ray Scattering (SAXS) available at the CERIC Austrian Partner Facility in Elettra Sincrotrone Trieste, scientists studied structure and behaviour of the hybrid materials. They discovered that hydrophobic drug molecules loaded-vesicles coat the surface of the ZIF-8, while liposomes had them distributed throughout the whole particle. Liposomes also accelerate the conversion of ZIF-8 to a denser phase ZIF-C in physiologically relevant media. These differences led to varied degradation behavior – liposomes were significantly more stable – in physiologically media. Moreover, even if both vesicle- and liposome-derived biocomposites achieved high encapsulation efficiency, researchers discovered that liposomes exhibited a better, sustained release behaviour.
This study explains how supramolecular lipid assemblies can influence MOF formation, stability, and, crucially, cargo encapsulation and release, highlighting the great potential of lipid/ZIF-8 hybrids as tunable (i.e. with personalised release profiles) platforms for drug delivery, particularly for hydrophobic and unstable therapeutic agents.
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