The Design of Antimicrobial Detachable Thin Films for the Study of Hepatic Infections

Microbial infections are a global problem. Due to the over and misuse of antibiotics, drug-resistant pathogens are becoming more common. It is imperative to explore broad spectrum antimicrobial approaches. In this work, we modified collagen/hyaluronic acid polyelectrolyte multilayers (PEMs) with the natural antimicrobial peptide, LL-37 to study hepatic infections. LL-37 was physisorbed and covalently linked to the surface of the PEMs. Escherichia coli DH10B were cultured in the presence of LL-37modified PEMs in bacterial adhesion and contact killing models. Physisorbed LL-37 PEMs prevented bacterial adhesion and could also kill pathogens in the surrounding environment due to the release of LL-37 from the film. Immobilized LL-37 PEMs resulted in less bacterial adhesion on the surface due to the presence of the peptide. Films were then placed in contact with primary rat hepatocytes as well as in hepatocyte/bacteria co-cultures. LL-37 input concentrations up to of 16μM did not exhibit cytotoxic effects on hepatocytes. The LL-37 modified PEMs exhibited a hepatoprotective effect on albumin and urea secretion functions in co-cultures. The hepatoprotective effects were dependent on the ratio of hepatocytes and bacteria as well as the concentration of LL-37. These findings are encouraging and demonstrate that LL-37 modified PEMs can be used to investigate hepatic infections caused by bacteria.