Backyard to battlefield: multifunctional medical foam for enhanced wound management

Abstract

Acute open wounds as a result of traumatic injuries are a prevalent issue for civilians and military personnel across the world. Unfortunately, advanced hospital care for these severe injuries is not always readily available, leaving the morbidity and mortality outcomes of people who suffer these injuries to rely on primary wound care, hopefully applied before it is too late. A complete understanding of traumatic injury's effect on the body remains elusive. However, known complications include hemorrhage and infection of wounds if not treated quickly and effectively. Many primary wound care products exist, but few can perform more than one function. For example, packing a wound with gauze can help stop bleeding, but will not do anything to combat infection. Thus, this work sought to generate a multifunctional therapeutic approach to primary wound care that includes bleeding (tranexamic acid) and infection (vancomycin) control agents delivered through a biopolymer carboxymethyl cellulose foam. This non-solidifying, volume-filling foam was hypothesized to improve the quality of care for those who sustain open wounds from traumatic injuries, especially those who are injured in rural or austere environments without immediate access to advanced care. This work is comprised of four aims that will contribute to the field of emergency wound care. The first aim included generating and characterizing the base foam responsible for delivering selected bleeding and infection control therapeutics topically to the wound. 200% tunability in temporal stability and volumetric expansion was demonstrated, indicating precise control over physical properties. The second aim was to evaluate the in vitro safety of the foam through monolayer live/dead staining of fibroblasts, one of the most prevalent cell types in skin. The foam and its constituents were found to be non-cytotoxic to both murine and human fibroblasts in vitro, indicating base-level safety of the material and potential for successful in vivo experimentation. The third aim focused on in vitro/ex vivo efficacy evaluation of antifibrinolytic and hemostatic properties of the foam on ovine blood with the chosen bleeding control therapeutic. Delivery with the foam demonstrated low clot lysis rates and mechanically robust blood clot rheology compared to other treatment formulations, indicating potential for successful in vivo experimentation in future work. The fourth and final aim evaluated the foam's in vitro/ex vivo antibiotic efficacy on methicillin-resistant Staphylococcus aureus with the selected infection control therapeutic. Delivery with the foam demonstrated 3-4 log bacterial killing of methicillin-resistant Staphylococcus aureus, indicating potential for successful in vivo experimentation in future work. Together, these aims provide novel preliminary data crucial to the product development process and in vivo implementation of the foam as a staple of primary wound care in acute open traumatic injuries.