An Antibacterial,Antioxidant Adherent Sponge Constructedfor Control of Arterial Bleeding Via Gallic Acid-Mediated Robust Assemblyof Fibrous Clay in Collagen

Acute hemorrhage death on battlefields, during clinical surgeries, and in major accidents is a widespread worldwide problem. Clay-based hemostatic materials have received considerable attention for their low cost and reliable clotting activity, especially in cases of severe bleeding, such as QuikClot, which is a kaolin-based hemostatic gauze that is preferred for battlefield resuscitation. However, the easy detachment of clay particles and the associated risk of thrombosis have seriously hindered the development of clay-based hemostatic materials. Here, inexpensive palygorskite (Pal) nanoclay was integrated into the collagen (COL) matrix by loading Ca²⁺ in the clay and further using gallic acid (GA) to mediate the robust assembly of clay on the COL matrix. This targeted interfacial design is a simple and gentle method that effectively improves the dispersion of the Pal particles and reduces the risk of shedding. Unlike QuikClot where the aqueous solution was significantly turbid after 2 min of ultrasonic washing, the aqueous solution of the composite sponge (Ca-Pal-GA-COL) remained clear and was accompanied by 82.71% of the mass residue after 10 min of ultrasonic washing. The composite sponge also exhibited excellent antibacterial (87.93% inhibition rate of Escherichia coli), antioxidant, and tissue adhesion properties. Importantly, the Ca-Pal-GA-COL sponge exhibited less blood loss (632 mg) and a shorter hemostasis time (151 s) in a rat femoral artery hemorrhage model than the medical gauze (3850 mg and 299 s), pure COL sponge (1627 mg and 201 s), and Pal-COL sponge (1494 mg and 193 s) in a co-mingled mode, which are comparable to those of QuikClot (559 mg and 142 s). Furthermore, certain tissue adhesion properties render the Ca-Pal-GA-COL sponge more suitable than QuikClot for severe femoral artery active bleeding scenarios. Cellular experiments confirmed that the composite dressing has a certain biosafety.