Gold-nanoparticles coated with the antimicrobial peptide esculentin-1a(1-21)NH2as a reliable strategy for antipseudomonal drugs.
Naturally occurring antimicrobial peptides (AMPs) hold promise as future therapeutics against multidrug resistant microorganisms. Recently, we have discovered that a derivative of the frog skin AMP esculentin-1a, Esc(1-21), is highly potent against both free living and biofilm forms of the bacterial pathogen Pseudomonas aeruginosa. However, bringing AMPs into clinics requires to overcome their low stability, high toxicity and inefficient delivery to the target site at high concentrations. Importantly, peptide conjugation to gold nanoparticles (AuNPs), which are among the most applied inorganic nanocarriers in biomedical sciences, represents a valuable strategy to solve these problems. Here we report that covalent conjugation of Esc(1-21) to soluble AuNPs [AuNPs@Esc(1-21)] via a poly(ethylene glycol) linker increased by ∼15-fold the activity of the free peptide against the motile and sessile forms of P. aeruginosa without being toxic to human keratinocytes. Furthermore, AuNPs@Esc(1-21) resulted to be significantly more resistant to proteolytic digestion and to disintegrate the bacterial membrane at very low concentration (5nM). Finally, we demonstrated for the first time the capability of peptide-coated AuNPs to display a wound healing activity on a keratinocytes monolayer. Overall, these findings suggest that our engineered AuNPs can serve as attractive novel biological-derived material for topical treatment of epithelial infections and healing of the injured tissue.



Despite conjugation of AMPs to AuNPs represents a worthwhile solution to face some limitations for their development as new therapeutics, only a very limited number of studies is available on peptide-coated AuNPs. Importantly, this is the first report showing that a covalent binding of a linear AMP via a poly(ethylene glycol) linker to AuNPs highly enhances antipseudomonal activity, preserving the same mode of action of the free peptide, without being harmful. Furthermore, AuNPs@Esc(1-21) are expected to accelerate recovery of an injured skin layer. All together, these findings suggest our peptide-coated AuNPs as attractive novel nanoscale formulation to treat bacterial infections and to heal the injured tissue.
Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
Bruno
B
Casciaro
Istituto di Scienze Applicate e Sistemi Intelligenti, CNR, Pozzuoli, Italy.
Maria
M
Moros
Instituto de Ciencia de Materiales de Aragon-CSIC/Universidad de Zaragoza, Spain.
Sara
S
Rivera-Fernández
Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy.
Andrea
A
Bellelli
Instituto de Ciencia de Materiales de Aragon-CSIC/Universidad de Zaragoza, Spain. Electronic address: jmfuente@unizar.es.
Jesús M
JM
de la Fuente
Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy. Electronic address: marialuisa.mangoni@uniroma1.it.
Maria Luisa
ML
Mangoni
D029845:Amphibian Proteins / Q000494:pharmacology*; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D059748:Proteolysis / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000648:ultrastructure
D029845:Amphibian Proteins; D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D020099:Coated Materials, Biocompatible; C092874:esculentin protein, Rana esculenta; D006046:Gold
Anti-biofilm activity; Antimicrobial peptide; Biostability; Electron microscopy; Gold nanoparticles; Membrane perturbation; Pseudomonas aeruginosa; Wound healing