Hemorrhages in the highly vascularized oral and maxillofacial region are not amenable to
control by tourniquet placement and often require the use of Topical Hemostatic Agents (THAs).
THAs are commonly used to control severe bleeding, this is the case in both military and civilian
pre-hospital care. The need for controlling hemostasis is even greater in patients undergoing
antithrombotic therapy or suffering from bleeding disorders. Meanwhile, oral wounds and
extraction sites are exposed to the rich microflora present in saliva, which can induce acute or
chronic infections that delay healing, and are complicated by the rise of antibiotic-resistant
species. THAs that are also antimicrobial would prevent these complications. Our laboratory
recently discovered a new class of high surface area, honeycomb silicate microsphere framework
(SMF) absorbents that prompt rapid hemostasis. Building on this discovery, our long-term goal is
to develop fast-action, topical hemostatic and antimicrobial agents using honeycomb SMFs
exchanged with gallium, which will further strengthen hemostatic efficacy and ensure antimicrobial
activity. The antimicrobial efficacy of exogenously supplied gallium (in the form of Ga3+) to
bacterial cells relies on its ability to replace Fe3+, thereby perturbing bacterial metabolism.
Concurrently, based on the literature, we hypothesize that the reported hemostatic action of ionic
gallium relies on its ability to flocculate fibrin. The expertise of our multidisciplinary team in silicate
chemistry, materials chemistry, hematology, and microbiology will be leveraged to develop
gallium-exchanged SMFs (Ga-SMFs). The project will initiate with the synthesis and
characterization of SMFs (Aim 1), including their hemostatic efficacy as well as the mechanisms
by which they promote hemostasis. Gallo-silicate microsphere frameworks (Ga-SMFs) will be
produced by ion-exchange (Aim 2). Physical properties, gallium release profiles, biocompatibility
and hemostatic efficacy will be characterized, and mechanisms by which gallium ion enhances
hemostasis will be investigated. Finally, the antimicrobial efficacy will be tested against a panel of
relevant bacteria. Direct deliverables are a new class of antimicrobial THAs with dual hemostatic
action, triggering rapid hemostasis and preventing infections, that could bear applications well
beyond oral and maxillofacial post-surgical hemorrhages.
