Microstructural evolution of multifunctional regenerated cellulose/collagen fibers toward protective medical textiles

Regenerated cellulose/collagen composite fibers hold great promise in biomedical textiles; however, their clinical translation is severely constrained by the trade-off between functionalization and mechanical integrity, as collagen aggregation inevitably induces internal structural defects. Here, multifunctional cellulose/collagen composite fibers were fabricated via tailored microstructural evolution and a crosslinking strategy. By regulating the composition of the C₂H₆O/H₂O/[Bmim]Cl coagulation bath, the coagulation kinetics and phase separation behavior were controlled, thereby suppressing structural defect formation and improving molecular chain orientation, which successfully enhanced the mechanical properties of the fibers. Furthermore, incorporating oxidized tannic acid (OTA) and citric acid constructed a robust 3D crosslinked network, reducing the peak heat release rate and total heat release by 85.6% and 90.4%, respectively, while endowing UV protection. Additionally, the fibers exhibited >99% antibacterial efficacy against E. coli and S. aureus with high cyclic durability and favorable biocompatibility. Overall, this eco-friendly fabrication approach provides a high-strength, fire-safe, and anti-infective material platform tailored for advanced protective medical textiles.