Layer-By-Layer Functionalized Gauze With Designed α-Sheet Peptides Inhibits E. coli and S. aureus Biofilm Formation

Microbial biofilms on wounds lead to longer hospital stays, mechanical debridement, and higher mortality. Amyloid fibrils stabilize the bacterial biofilm's extracellular matrix (ECM) and represent a potential anti-biofilm target. As previously reported, de novo α-sheet peptides inhibit amyloid fibrillization and reduce biofilm formation in several bacterial species. Alginate (ALG) and chitosan (CH) are widely used in wound dressings due to their adhesive and antimicrobial activity. Here, we describe a layer-by-layer (LbL) functionalized gauze with alternating layers of ALG and CH loaded with α-sheet peptides for controlled release and biofilm inhibition at a wound site. Material analysis indicated successful LbL polyelectrolyte deposition and peptide incorporation. The LbL gauze facilitated controlled peptide release for 72 h with an initial burst delivery and demonstrated good biocompatibility with no toxicity towards human fibroblasts. The LbL gauze was assessed against Escherichia coli biofilms and reduced colony forming units (CFUs) of adherent bacteria by 81% and 96% as compared to the plain gauze for non-antibiotic and antibiotic (+gentamicin) conditions, respectively. A similar reduction in biofilm formation and increase in antibiotic susceptibility was observed for tests with Staphylococcus aureus and vancomycin. Thus, LbL gauze with incorporated α-sheet peptides demonstrated anti-biofilm properties for both gram-negative and gram-positive bacteria and presents an alternative wound dressing for the prevention of biofilm-associated infections.