A hemostatic tissue sealant sponge and a spray for acute wounds are disclosed. The sponge comprises hydrophobically modified polymers that anchor themselves within the membrane of cells in the vicinity of the wound. The seal is strong enough to substantially prevent the loss of blood inside the boundaries of the sponge, yet weak enough to substantially prevent damage to newly formed tissue upon recovery and subsequent removal of the sponge. In examples, the polymers inherently prevent microbial infections and are suitable for oxygen transfer required during normal wound metabolism. The spray comprises hydrophobically modified polymers that form solid gel networks with blood cells to create a physical clotting mechanism to prevent loss of blood. In an example, the spray further comprises at least one reagent that increases the mechanical integrity of the clot. In another example, the reagent prevents microbial infection of the wound.