Anti-bacterial properties of hyperbranched poly (epsilon-lysine) peptides dendrons for wound dressing applications: molecular specie-specific effects

Background: Wound dressings, as tulles or hydrogels, are the devices of choice for the management of wounds and they are also made available to clinicians in formulations integrating silver nanoparticles as antibacterial agents. Nevertheless, the management of wounds is significantly affected by bacterial infections that limit healing to only 45% of the cases. Results: Poly(epsilon-Lysine) branched peptides, called dendrons, were synthesised with different levels (also known as generations) of branching by an automated solid-phase peptide method. Production at hundreds of miligram scale and over 90% of purity were obtained. A study of the antimicrobial properties of these branched peptides, when in soluble form or used to impregnate commercial wound dressings, was performed on two bacterial species relevant to wound infections, Staphylococcus aureus and Pseudomonas aeruginosa. The data showed the antibacterial activity of these molecules, when presenting three generations of molecular branching, on Staphylococcus aureus both in planktonic and biofilm conditions. Conclusions: The present study shows that hyperbranched poly(epsilon-Lysine) dendrons can be used for wound S. aureus infection prevention, as an alternative to silver, either in soluble form or when used to impregnate the fibres of clinically-available, tulle- or hydrogel-based wound dressings.