H₂O₂-driven dual-functional modification of Tremella fuciformis polysaccharides: Molecular weight reduction and...

High molecular weight and inert functional groups limit the biomedical utility of natural polysaccharides, such as Tremella fuciformis polysaccharides (TFPs). In this study, we describe a H₂O₂-driven, one-step method for the concurrent oxidation and degradation of TFPs, which reduces the molecular weight from 1079.6 to 4.6 kDa while introducing aldehyde (0 %-0.99 %) and carboxyl (1.22 %-9.80 %) groups. By altering the H₂O₂ concentration, we obtained oxidized TFPs (OTFPs) with defined properties, namely OTFP-1 (13.5 kDa, 0.36 % aldehyde) exhibiting low cytotoxicity (73 % viability at 15 mg/mL); OTFP-3 (5.0 kDa, 0.80 % aldehyde) exhibiting enhanced antioxidant (DPPH/ABTS: 83 %/89 %), anti-inflammatory (IL-6/TNF-α reduction: 46 %/53 %), and ultraviolet B repair (36 % recovery) activities; and OTFP-4 (4.6 kDa, 0.99 % aldehyde) displaying broad-spectrum antibacterial activity (minimum inhibitory concentration: 7-9 mg/mL). The aldehyde groups also yielded injectable, self-healing hydrogels through dynamic Schiff base bonds. This green strategy decouples molecular weight and functionalization and provides a versatile platform for tailored bioactive materials.