Injectable nanocellulose-based polylipoic acid hydrogels with tunable rheology, strong adhesion and multifunctional bioactivity.

The development of injectable hydrogels that combine strong tissue adhesion, suitable rheological properties and effective antibacterial/antioxidant activities remains a major challenge for biomedical applications. Herein, we design nanocellulose-based dynamic hydrogels by integrating dopamine-grafted cellulose nanofibers (DCNF) with polylipoic acid (PTA). The DCNF not only constructs a percolated nanofibrous network that precisely regulates viscosity, shear-thinning behavior and structural recovery after injection, but also stabilizes PTA by quenching terminal sulfur radicals, thereby suppressing depolymerization. As a result, the obtained hydrogels exhibit excellent injectability, robust and repeatable adhesion on various substrates, and rapid network recovery, together with effective antibacterial activity against S. aureus and E. coli and pronounced antioxidant capacity. In vitro hemolysis and cytocompatibility assays confirm the good biocompatibility of the DCNF/PTA hydrogels. This work provided a simple nanocellulose-centered strategy to construct injectable, adhesive and bioactive hydrogels as promising handling performance in vitro for transdermal drug delivery and other biomedical applications.