Surface-functionalized alginate/polyurethane nonwoven with antibacterial and unidirectional fluid transport properties for accelerated healing of infected wound

Alginate nonwovens are favored as wound dressings due to their biocompatibility and fluid absorption. However, their limited antibacterial activity and poor exudate drainage restrict their use in infected wound care. To address these challenges, a sequential surface-functionalization strategy was developed to fabricate a guanidine-modified alginate/polyurethane (G-Alg/PU) nonwoven with antibacterial and unidirectional liquid transport ability. The electrospun hydrophobic PU layer was stably bonded to the alginate nonwoven fabric via hot-pressing process, enhancing the structural integrity while maintaining breathability. Electrostatic grafting of guanidine endowed G-Alg/PU with improved antibacterial property with the inhibition rate reaching 99.9 % against Escherichia coli and Staphylococcus aureus. Driven by the hydrophilic-hydrophobic gradient across the layers, G-Alg/PU achieved unidirectional liquid transport. In vitro assays confirmed the good cytocompatibility, hemocompatibility and hemostatic properties of G-Alg/PU. In vivo application proved that G-Alg/PU effectively promoted the infected wound healing by controlling exudate, reducing inflammation, and enhancing collagen deposition. This study provides an effective layer-functionalization strategy for developing alginate nonwovens-based dressings with integrated functionalities for advanced wound care.