(379e) Polymeric Foams Capable of Arresting Bleeding from Non-Compressible Injuries

Bleeding from injuries in the truncal region is a leading cause of fatalities in the military and in young adults. Direct pressure cannot be applied to stop bleeding in these cases. Our lab has been particularly interested in developing foams to treat such ‘non-compressible’ hemorrhage. Foams can be effective because the expansion of the foam in the injured cavity can counteract blood loss without the need for compression. As an active ‘hemostatic agent’ in these foams, we use hydrophobically modified (hm) derivatives of biopolymers like chitosan and alginate (termed hmC and hmA, respectively). These polymers have the ability to coagulate blood cells and thus stop bleeding.

In this talk, we will describe aqueous foams that can be delivered out of a double-barreled syringe by combining precursors in the two barrels that produce bubbles of gas in situ. In addition, one barrel contains hmC and the other hmA, and the amphiphilic nature of these polymers enables them to stabilize gas bubbles without the need for additional surfactants. Most interestingly, these polymer-based foams have enhanced rheological properties compared to typical foams that can be prepared in a lab. This rheological enhancement is quantified in our work, and is due to electrostatic interactions between the cationic hmC and the anionic hmA chains. Preliminary studies in animal wound models also confirm that hmC-hmA foams form effective barriers to blood loss due to their greater mechanical integrity.