Alginate-coated ZIF-8 metal-organic framework as a green and bioactive platform for controlled drug release

This work reports an in-situ approach to both synthesis and coat of an imidazole Zn-based metal-organic framework (ZIF-8 MOF) using sodium alginate, to achieve an effective platform for controlled drug release. The alginate-coated ZIF-8 nanoparticles (ZIF-8@alginate NPs) were prepared through a convenient and green one-pot solvent-free mechanochemical ball-milling of the MOF components and sodium alginate powder. According to several characterization techniques, the MOF particles were well distributed and embedded inside the polymer. It was expected that this drug delivery system (DDS) overcomes the problem of rapid degradation of ZIF-8 in acidic pH, to be utilizable as a DDS for acid-sensitive drugs while improving the drug's bioavailability. Metformin, an oral antihyperglycemic agent for the treatment of type II diabetes was chosen as a model drug. It was trapped inside the alginate-coated ZIF-8 pores. The regular porosity of the DDS and in particular, the presence of the zinc ions, could help to increase the effectiveness and controlled release of metformin.