Engineering Multifunctional Capsules through the Assembly of Metal–Phenolic Networks

• DOI: 10.1002/ange.201311136
• Publication Date: 2014-04-02T15:29:18Z
• Authors: Junling Guo; Yuan Ping; Hirotaka Ejima; Karen Alt; Mirko Meissner; Joseph J. Richardson; Yan Yan; Karlheinz Peter; Dominik von Elver...; Christoph E. Hage...; Frank Caruso
• Keywords: 610; Contrast Media; Polyphenols; Capsules; 02 engineering and technology; 540; Magnetic Resonance Imaging; 01 natural sciences; Catalysis; Permeability; Cell Line; 0104 chemical sciences; Mice; Phenols; Coordination Complexes; Metals; Positron-Emission Tomography; Animals; Tomography, X-Ray Computed; 0210 nano-technology; Tannins

AbstractMetal–organic coordination materials are of widespread interest because of the coupled benefits of inorganic and organic building blocks. These materials can be assembled into hollow capsules with a range of properties, which include selective permeability, enhanced mechanical/thermal stability, and stimuli‐responsiveness. Previous studies have primarily focused on the assembly aspects of metal‐coordination capsules; however, the engineering of metal‐specific functionality for capsule design has not been explored. A library of functional metal–phenolic network (MPN) capsules prepared from a phenolic ligand (tannic acid) and a range of metals is reported. The properties of the MPN capsules are determined by the coordinated metals, allowing for control over film thickness, disassembly characteristics, and fluorescence behavior. Furthermore, the functional properties of the MPN capsules were tailored for drug delivery, positron emission tomography (PET), magnetic resonance imaging (MRI), and catalysis. The ability to incorporate multiple metals into MPN capsules demonstrates that a diverse range of functional materials can be generated.