Construction of 3D-fabric-based triple-decker agar/sodium alginate/Ca2+ dual-network composite for wound dressing

This study designed a novel multifunctional Janus structure dressing (DNCD dressing) composed of spacer fabric, agar/sodium alginate/calcium ion dual-network aerogel, methylene blue, and AgNO 3 -added thermoplastic polyurethane nanofiber membrane. The unidirectional liquid transport and absorbency tests prove that the DNCD dressing can unidirectionally transport liquids within just two seconds and possesses a liquid absorption ratio of 875.3 %. The unique open structure formed by the spacer fabric and liquid transport channels provides excellent air permeability as well as a suitable water vapor transmission rate, reaching 584.96 mm/s, 10.3 L/min, and 1104.82 g/m 2 /24 h, respectively. The exceptional compressive strength (216.78 kPa) and compressive modulus (515.23 kPa) of the dressing can provide protection for the wound. Antibacterial tests demonstrate that the silver ion-added DNCD dressing can eradicate >99 % of Escherichia coli and Staphylococcus aureus , while the added methylene blue can effectively monitor the survival status of bacteria. The low BCI value and the hemolysis ratio of <5 % indicate that the DNCD dressing has a certain hemostatic ability and does not cause hemolysis. The results of cytotoxicity tests and full-thickness skin defect models show that the DNCD dressing has good cytocompatibility and the potential to promote wound healing.