Biomass-derived dextran for high-value bioproducts: From production and functionalization to quality-by-design...

Dextran is a microbial polysaccharide with a long pharmaceutical history and renewed relevance as a biomass-derived platform macromolecule for high-value bioproducts. This structured narrative review synthesizes peer-reviewed literature published between 2020 and 2025, identified through a structured narrative search conducted between January and March 2025 and a final targeted update completed in December 2025. The review integrates three connected dimensions: (i) dextran production from sucrose-rich biomass streams, particularly sugarcane molasses, and the associated techno-economic and purification challenges; (ii) functionalization strategies, including oxidation, methacrylation, disulfide incorporation, thermoresponsive grafting, and nanocomposite design; and (iii) emerging applications in hydrogel-based wound dressings, regenerative matrices, responsive delivery systems, biosensing interfaces, and other high-value bioproducts. Emphasis is placed on hydrogel-based wound-healing, regenerative, and stimulus-responsive delivery systems, because these are the most experimentally mature and translation-ready dextran product archetypes. The recent literature shows a clear transition from passive hydrated carriers to multifunctional dextran networks that combine injectability, self-healing, adhesion, antimicrobial and antioxidant activity, controlled release, and stimulus responsiveness. However, the principal barrier to translation is not the lack of chemical versatility but the insufficiently reproducible control of molecular weight distribution, degree of substitution, impurity burden, residual reagents, sterilization compatibility, and shelf stability. A quality-by-design roadmap is proposed to connect feedstock variability, polymer specification, network architecture, and end-use performance through defined critical quality attributes and critical process parameters. Dextran is most competitive when biomass valorization, aqueous processing, modular functionalization, and application-specific specification are integrated into a single development framework rather than treated as isolated steps.