Cationic homopolypeptides: A versatile tool to design multifunctional antimicrobial nanocoatings

Area of Science:

• Biomaterials Science
• Infectious Disease Research
• Regenerative Medicine

Background:

• Postoperative infections are a significant challenge following implant surgery.
• Developing effective antimicrobial coatings using antibiotic alternatives is crucial.

Purpose of the Study:

• To investigate polycationic homopolypeptides combined with hyaluronic acid (HA) as an antimicrobial coating.
• To evaluate the efficacy of poly(l-arginine) (PAR)/HA coatings against various bacteria and their impact on host cells.

Main Methods:

• Layer-by-layer assembly of poly(l-arginine), poly(l-lysine), or poly(l-ornithine) with hyaluronic acid.
• Assessment of antimicrobial activity via contact-killing mechanism against Gram-positive, Gram-negative, and antibiotic-resistant bacteria.
• Evaluation of cell adhesion, nitric oxide production, and in vivo performance on coated hernia meshes in a rabbit model.

Main Results:

• Polycationic homopolypeptide coatings demonstrated contact-killing antimicrobial activity.
• Poly(l-arginine) (PAR)/HA coatings showed superior performance, promoting cell adhesion and nitric oxide production for tissue regeneration.
• No bacterial resistance developed against PAR, and the coating inhibited eukaryotic pathogen growth.
• In vivo studies confirmed antibacterial properties and lack of chronic inflammation.

Conclusions:

• PAR/HA coatings offer a promising, synergistic approach to combatting medical device-associated infections, including those caused by antibiotic-resistant bacteria.
• The polycation chain length and mobility are critical for antimicrobial efficacy.
• PAR/HA coatings facilitate tissue integration and regeneration, presenting a dual-action solution for surgical implants.