Certain plant polysaccharides such as alginates and pectins have a modular structure determined by the biosynthesis. The modular structure of alginates, their analysis, and their importance in the gelation to form biomaterials will be briefly discussed.
A second approach to modular polysaccharides involves covalently assembling oligosaccharides from different sources to form hybrid block polysaccharides. This allows the design of new biopolymers with multiple built-in properties analogous to synthetic block polymers. We have explored the use of two key bioconjugation methods often used in glycosciences, namely dioxyamine and dihydrazide chemistry to form a range of diblock polysaccharides based on alginate, chitin, chitosan, dextran and β-1,3-glucans. These studies also include the use of 2-picoline borane as reductant. Recent results will be presented.