Photocrosslinkable Chitosan–Nanocellulose Composite Hydrogels for Hemostatic, Antibacterial, and Soft-Tissue Biomedical Applications

Bleeding and bacterial infection remain major challenges in surgical procedures. Thus, hemostatic biomaterials capable of controlling bleeding rapidly while preventing microbial contamination are highly desirable. This study developed and evaluated photocrosslinkable composite hydrogels made of methacrylated chitosan (ChiMA) and methacrylated oxidized cellulose nanofibers (OCNFMA) for antibacterial hemostatic applications. Chitosan (Chi) was methacrylated using methacrylic anhydride, cellulose nanofibers were oxidized with sodium periodate, and 2-aminoethyl methacrylate (AEMA) was added to introduce photocrosslinkable groups. For the preparation of composite hydrogel networks, the precursor solutions were mixed and photocrosslinked under UV irradiation (365 nm) in the presence of lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). A Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and rheological analysis were utilized to characterize the materials. Hydrogels were evaluated for swelling behavior, degradation profile, and blood clotting ability. Furthermore, antibacterial activity against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) was evaluated, and cytocompatibility was evaluated using NIH3T3 fibroblasts and MC3T3 preosteoblasts. Incorporating OCNFMA with low degrees of functionalization (L) or high degrees of functionalization (H) at different ratios into the ChiMA network significantly influenced the physicochemical and structural properties of the hydrogels. The composite hydrogels exhibited interconnected porous structures, improved mechanical stability, and tunable swelling and degradation behavior. Furthermore, some formulations demonstrated measurable antibacterial activity against both bacterial strains. Moreover, cytocompatibility studies revealed that the composite hydrogels supported higher cell viability than ChiMA alone. The developed ChiMA–OCNFMA composite hydrogels exhibit promising physicochemical, antibacterial, and biological properties. The findings suggest that the materials may be useful as multifunctional hydrogels for wound management, as well as candidates for broader biomedical applications.