We report two ternary phase diagrams that show the synthesis conditions to prepare protein@ZIF biocomposites with different phases, including BSA@ZIF-C and insulin@ZIF-C. For each biocomposite, we measured distinct encapsulation efficiency and release profile properties.

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MOFs have demonstrated outstanding properties for the protection and controlled release of different bio-entities, from proteins to living cells. Carbohydrates, as pure molecules or as a component of proteins and cells, perform essential biological functions. Thus, an understanding of the role of carbohydrates in the formation of MOF-based bio-composites will facilitate their application to biotechnology and medicine. Here, we investigate the role of carbohydrate molecular weight and chemical functionalization in the formation of carbohydrate@MOF composites. We find that chemical functionalization, such as carboxylation, that leads to an enhancement of metal cation concentration at the surface of the molecule triggers the rapid self-assembly of the MOF material, zeolitic-imidazolate framework 8 (ZIF-8). Furthermore, we determine the encapsulation efficiency and measure the release properties of the carbohydrate under controlled conditions. Our findings show that MOFs can be used to prepare a new class of biocomposites for the delivery of carbohydrate-based therapeutics. † Electronic supplementary information (ESI) available: Additional figures, movies and experimental details. Substrates used and their formulas, schematic overviews of the performed syntheses and workups, time-dependent MOFformation experiments induced by different carbohydrates and concentrations, yield calculations, SEM image of ZIF-8 on glass and paper, FTIR spectra of the starting materials and the obtained products, schematic of the ion-permeable spherical model, kinetics studies, UV-Vis analyses, photographs of solutions using different polysaccharides, and video showing the succesfull biomimetic mineralisation of CM-dextran. SeeCarbohydrate-based therapeutics are relevant drugs for the treatment of cancer, diabetes, viral and bacterial infections. Therefore the efficient encapsulation and controlled release of carbohydrates has great potential in biomedicine. Here, we present a successful strategy to trigger the spontaneous crystallization of metal-organic frameworks (MOFs) on carbohydrates. The encapsulation of carbohydrates within ZIF-8 and polymorphs (zinc-imidazolate-based MOFs) can be obtained in water. The identification of conditions suitable for the successful preparation of the composite were experimentally and computationally identified. By controlling the chemical functionalization of the carbohydrate, the formation of bio-composites can be obtained in seconds. A 100% encapsulation efficiency was obtained. The controlled release of carbohydrates from the MOF biocomposite was demonstrated. This proof-of-concept study shows that a new generation of MOF biocomposites can be exploited for biomedical applications.

Glycosaminoglycans (GAGs) are biomacromolecules necessary for the regulation of different biological functions. In medicine, GAGs are important commercial therapeutics widely used for the treatment of thrombosis, inflammations, osteoarthritis and wound...

Here we systematically varied the composition of the relative amounts of ligand (2-methylimidazole), metal precursor (Zn(OAc)2∙2H2O, and protein to prepare a series of protein@ZIF biocomposites. The effect of post synthetic treatments (i.e. washes with water or water/ethanol) was investigated. The XRD data of the examined samples were used to construct ternary diagrams. Five different phases were identified. The encapsulation efficiency (of bovine serum albumin and insulin) were phase dependent.