Antimicrobial characterization of a titanium coating derived from mussel-glue and Bothrops asper snake venom for the prevention of implant-associated infections caused by Staphylococcus

Abstract

Background: Proliferation of bacteria, such as Staphylococcus aureus and Staphylococcus epidermidis, on orthopedic implants has been a challenge in orthopedic surgery, highlighting the problem of the increasing antibiotic resistance and the necessity to develop new antimicrobial agents. In this sense, antimicrobial peptides are promising candidates, which can be attached to titanium surfaces in order to make them safer. Mytilus mussels are characterized by adhering efficiently to a wide variety of surfaces, especially metallic ones, through adhesive proteins with a high content of dihydroxyphenylalanine, which is a post-translational modification of tyrosine.

Results: This work refers to the synthesis of a coating based on a bifunctional peptide that combines a sequence derived from the mussel foot protein-5 and the antimicrobial peptide pEM-2, derived from Bothrops asper snake venom. The adhesive properties of this bifunctional peptide were evaluated, as well as the adhesive sequence without the pEM-2, using a Quartz Crystal Microbalance. The results showed that the presence of the antimicrobial peptide improved the adhesion; however, a loss of the bactericidal activity was observed. Even so, the adhesive sequence by itself exhibited an important antifouling activity, preventing S. aureus and S. epidermidis adhesion to titanium by 75% and 45%, respectively, although the result against S. epidermidis was not significant.

Conclusions: A 13-residue peptide derived from a natural and biocompatible source, like a Mytilus mussel adhesive protein, could be projected as a protective agent on titanium surfaces against S. aureus and S. epidermidis, being responsible for two thirds of the cases of orthopedic implant infection.