Kang Liang1 2 Joseph Richardson3

1, University of New South Wales, Sydney, New South Wales, Australia
2, University of New South Wales, Sydney, New South Wales, Australia
3, The University of Melbourne, Melbourne, Victoria, Australia

We report for the first time the biomimetic mineralization of metal-organic frameworks from biomolecules and living cells. This bioinspired mineralization process leads to the formation of ultra-porous crystal coatings around bioentities, showing promise in various biotechnological applications.
Metal-organic frameworks (MOFs) have attracted tremendous research efforts in the last two decades. This ultra-porous, organic-inorganic hybrid material exhibits extraordinary degree of variability of their chemical structures and physiochemical properties and has shown promise in clean energy and catalysis applications[1]. However, the application in biotechnology is still in its infancy, largely owing to their harsh synthetic conditions that makes them incompatible to most of the biomolecules of interest.
Inspired by biological biominerlization processes, scientists have been trying to adopt and transform this natural process into ‘biomimetic’ strategies for the preparation of the next generation of functional materials[2]. Here, we present the first example of unconventional biomineralization of MOFs[3]. This biologically induced self-assembly process leads to the formation of a highly porous, protective MOF shell around biomacromolecules (e.g. proteins, enzymes, polysaccharides, and DNA)[3-6], and around living entities (e.g. prokaryotic and eukaryotic cells)[7-8]. As a result, the porous MOF shell allows selective transport of small molecules, enabling selective interaction of the encapsulated biomolecules and cells with the external environment, while significantly enhancing their stability. Moreover, the biomineralized MOF coatings can be engineered responsive to biological triggers, which enable them to release cargo at target site on demand. This discovery proposes MOFs as ideal candidate materials for a range of biotechnological applications, such as industrial biocatalysis, drug delivery, biomedical lab-on-a-chip device fabrication, and cell manipulation[2-8].

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