Enzymatic Synthesis of Artificial Polysaccharides

Polysaccharides are the most important renewable polymers on Earth and hold an enormous potential for the production of ecofriendly functional materials. In addition to being sustainable, they have superior properties to synthetic polymers, particularly in the biomedical field where biocompatibility and biodegradability are vital. Derivatization of polysaccharides obtained from plant biomass paves the path forward for the design and manufacturing of advanced materials with specific properties adapted to meet definitive needs. However, these advances have been severely limited due to issues with establishing structure-property relationships, which are hampered by the heterogeneity of target polysaccharides and the random distribution of functional groups obtained after their chemical modification. An accurate correlation of structure-property relationships at multiple length scales requires substrates with defined sizes, sequences, and substitution patterns. Such tailor-made polysaccharides may be obtained by implementing a bottom-up approach, starting from monosaccharide or oligosaccharide building blocks followed by their polymerization and substitution through catalysis by different carbohydrate-active enzymes such as glycosynthases, phosphorylases, sucrases, and glycosyltransferases. Recent progress in the enzymatic synthesis of artificial polysaccharides is reviewed, with an emphasis on the potential of the synthesized products, either as new materials or as tools to study structure-property relationships. The obtained information will guide future developments of rationally designed biobased materials for industrial and biomedical applications.