Delivering living medicines with polysaccharide derivatives for disease treatment.

Living medicines represent a revolutionary approach to modern therapeutics, but their effective delivery and in vivo functional maintenance pose significant challenges. Polysaccharide derivatives have emerged as ideal materials for the construction of advanced delivery systems owing to their exceptional biocompatibility, ECM-mimetic microenvironment and mechanically tunable properties. This review systematically analyses the applications of polysaccharide derivatives in live medicine delivery, elucidating their chemical modification strategies, design principles of delivery systems, and disease-specific applications. We focused on the latest advances in polysaccharide-based delivery systems for inflammatory bowel disease, cancer, central nervous system disorders, and tissue regeneration, while addressing the challenges in clinical translation and future directions. In summary, this review thus bridges fundamental material design with translational goals, offering guidance for developing effective polysaccharide-based delivery systems for living medicines.