An Antibacterial, Antioxidant Adherent Sponge Constructed for Control of Arterial Bleeding Via Gallic Acid-Mediated Robust Assembly of 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 Ca 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 ), 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.