Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.
Methods for permanent localisation, dynamic localisation and spatial control of functional materials within MOF crystals are critical for the development of miniaturised MOF-based devices for a number of technological applications.
Understanding the stability of zeolitic imidazolate framework-8 (ZIF-8) under physiological conditions is critical in biotechnology and biomedicine for biosensing, biocatalysis, and drug delivery. The use of ZIF-8 has shown that this metal organic framework (MOF) and its derived bio-composites can degrade in presence of buffer solutions. Here we present an in-depth analysis of the structural and chemical changes of pure ZIF-8 particles exposed to phosphate buffered saline (PBS) media. Two different particle sizes (2 μm and 250 nm) were selected and the decomposition operated by 10 mM PBS (aka 1X) was studied using powder X-ray diffraction (PXRD), Fourier transformed infrared spectroscopy (FTIR), time resolved atomic force microscopy (AFM), in situ small angle X-ray scattering (SAXS), and 31P NMR.
16 September 2013 in Journal of Materials Chemistry A
The high and regular porosity of metal–organic frameworks (MOFs) provides exceptional properties suitable for technological applications. The increasing interest of the scientific community is based on the exploration of these advantageous properties for industrial applications. Pure MOFs are specifically designed to offer a huge surface area; such a high specific surface area has been explored and exploited for gas storage, separation, or catalysis in a variety of chemical processes. A different and promising scientific trend aims to combine MOFs with extrinsic functionalities such as functional nanoparticles; this strategy enables the preparation of new nanocomposite materials with unprecedented properties. An interesting case is offered by the synergic combination of magnetic particles with MOF crystals. In the resulting nanocomposite material, the adaptive functional responses can be triggered by an external magnetic field. In this context, different protocols have been developed for the efficient preparation of magnetic framework composites (MFCs), a class of materials that combines magnetic nano- or micro-particles with MOFs crystals. This application paper highlights the progress on MFCs for drug delivery, environmental control, catalysis, sensing and miniaturized device fabrication.