Gallium Complex-Functionalized P4HB Fibers: A Trojan Horse to Fight Bacterial Infection

Broadband administration and overuse of conventional antibiotics contribute to antibiotic resistance, demanding for alternative strategies. Metal ions, among them gallium (Ga), gained increasing interest as antibacterial agents. Ga can be complexed in a protoporphyrin ring (GaPPIX) and thereby shares similarities with the heme molecule and functions as a Trojan horse that is internalized by bacteria. Different to iron in heme, Ga interferes with the metabolism, induces bacterial death, and can therefore be used as an antibacterial treatment. Here, electrospun membranes of poly(4-hydroxybutyrate) (P4HB) functionalized with GaPPIX were developed. P4HB was biosynthesized and spun into non-wovens, displaying fiber diameters of ∼700 nm. In vitro, GaPPIX-loaded membranes induced a median log 2 reduction of viable Staphylococcus aureus. In culture with human dermal fibroblasts, no cytotoxic effects were observed. These antibacterial membranes have the potential to contribute to alternative antibacterial strategies for the treatment of skin wounds.