Design of Multifunctional Polysaccharides for Biomedical Applications: A Critical Review

Background: Natural polysaccharides such as alginates, pectins, and chitins, possess a wide versatility in addition to the variability of the typical structural features of polysaccharides, as they include amino-, amido-, carboxylic acid, and esters groups. Objective: These functional groups can be exploited to graft specific moieties and macromolecules, thus tailoring the specific characteristics when envisioning improved functionality, such as targeted-drug delivery, antimicrobial, and thermo- or pHresponsiveness. Ad hoc covalent modifications of the polysaccharidic backbone can promote the loading and interactions with a wide variety of both hydrophilic and hydrophobic substances, as well as enhanced cell adhesion able to promote regeneration events. Additionally, enzymatic modifications have been conducted to have precise control of both functional groups and biodegradation. Conclusion: This review intends to give an overview over chemical and enzymatic reactions to modify the backbone of polysaccharides aiming to exploit organic chemistry tools applied to meet the diverse needs of biomedicine.