Single Crystals of V‐Amylose Complexed with Bicyclic Organic Compounds

Bottom-Up Synthesized Glucan Materials: Opportunities from Applied Biocatalysis

Linear d-glucans are natural polysaccharides of simple chemical structure. They are comprised of d-glucosyl units linked by a single type of glycosidic bond. Noncovalent interactions within, and between, the d-glucan chains give rise to a broad variety of macromolecular nanostructures that can assemble into crystalline-organized materials of tunable morphology. Structure design and functionalization of d-glucans for diverse material applications largely relies on top-down processing and chemical derivatization of naturally derived starting materials. The top-down approach encounters critical limitations in efficiency, selectivity, and flexibility. Bottom-up approaches of d-glucan synthesis offer different, and often more precise, ways of polymer structure control and provide means of functional diversification widely inaccessible to top-down routes of polysaccharide material processing. Here the natural and engineered enzymes (glycosyltransferases, glycoside hydrolases and phosphorylases, glycosynthases) for d-glucan polymerization are described and the use of applied biocatalysis for the bottom-up assembly of specific d-glucan structures is shown. Advanced material applications of the resulting polymeric products are further shown and their important role in the development of sustainable macromolecular materials in a bio-based circular economy is discussed.

Targeted delivery of flufenamic acid by V-amylose

Aim: Controlled release of flufenamic acid by helical V-amylose to achieve enzyme-responsive, targeted release of the cargo drug. Materials & methods: Solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS NMR), Fourier transform IR and x-ray diffraction (XRD) analysis validated the entrapment of flufenamic acid inside the helical structure of V-amylose. Scanning electron microscopy (SEM) investigations established the morphology of conjugates in simulated gastric environment (pH 1.2) and simulated intestine media (pH 7.2) containing hydrolyzing enzyme. Results & discussion: V-amylose–flufenamic acid complex displayed a sustained release of flufenamic acid for 12 h with a marked stability in simulated gastric pH, while showing a controlled release of drug in simulated intestine media. Conclusion: The V-amylose–flufenamic acid system achieves intestine-targeted delivery of flufenamic acid. The controlled release of flufenamic acid may ensure minimal ulcerogenicity and application as enteric coatings.