Mussel-inspired antimicrobial coating on PTFE barrier membranes for guided tissue regeneration

Guided tissue regeneration procedures to treat periodontitis lesions making use of polytetrafluoroethylene (PTFE) membranes exhibit large variability in their surgical outcomes, due to bacterial infection following implantation. This work reports on a facile method to obtain antimicrobial coatings for such PTFE membranes, by exploiting a mussel-inspired approach and in-situ formation of silver nanoparticles (AgNPs). PTFE films were initially coated with self-polymerized 3,4-dihydroxy-DL-phenylalanine (DOPA) (PTFE-DOPA), then incubated with AgNO3 solution. In the presence of catechol moieties, Ag+ ions reduced into Ag0, forming AgNPs of around 68 nm in the polyDOPA coating on PTFE membranes (PTFE-DOPA-Ag). The x-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy analyses indicated that the AgNPs were distributed quite homogeneously in the polymeric membrane. The antimicrobial ability of PTFE-DOPA-Ag membranes against Staphylococcus aureus and Escherichia coli was assessed. In vitro cell assay using NIH 3T3 fibroblasts showed that, although cells were adhered to PTFE-DOPA-Ag membranes, their viability and proliferation were limited demonstrating again the antibacterial activities of PTFE-DOPA-Ag membranes. This work provides proof-of-concept study of a new versatile approach for AgNPs coating, which may be easily applied to many other types of polymeric or metallic implants through exploiting the adhesive behavior of mussel-inspired coatings.