Ultrasonic-driven synthesis of Cu-chlorophyllin-stabilized silver nanoparticles for high-efficiency antimicrobial surgical suture coatings

Abstract

• Ag 0 NPs -Chl Cu was prepared through an ultrasonic-assisted chemical reduction approach. • Ag 0 NPs can replace Cu (II) in copper-chlorophyllin to form Ag 0 NPs -Chl Cu . • Ag 0 NPs -Chl Cu were adsorbed on surgical sutures using the Layer-by-Layer technique. • The antimicrobial activities of Ag 0 NPs -Chl Cu were assessed against pathogenic bacteria. • The nanolayer films of Ag 0 NPs -Chl Cu were not inherently toxic to human cells. A novel Cu-chlorophyllin-stabilized silver nanoparticle (Ag 0 NPs -Chl Cu ) with potent antimicrobial properties was synthesized for the first time using an ultrasonically driven chemical reduction approach. In this approach, Cu-chlorophyllin (Chl Cu ) acts as a stabilizing ligand, while sodium borohydride functions as the chemical reductant. The formation mechanism of Ag 0 -NPs CHL was elucidated, revealing that ultrasonic irradiation facilitates the in situ reduction of Ag (I) and its subsequent incorporation into the Chl Cu complex. Four pyrrole rings coordinate with Ag 0 NPs through four nitrogen atoms, which serve as adsorption sites for the anchorage of Ag 0 -NPs CHL . Characterization by XPS revealed the presence of Ag-N bonding involving pyrrole units on the FCC structure of Ag 0 NPs . Ag 0 NPs -Chl Cu demonstrated a zeta potential of (-) 35.57±3.54 mV with a spherical shape and an average size of 6.72±1.72 nm, resulting in a stable colloidal dispersion with a monodispersed index. The synthesized Ag 0 -NPs CHL nanocomposites were subsequently deposited onto polyamide surgical sutures via an electrostatic Layer-by-Layer (LbL) self-assembly technique. The coated sutures exhibited >99.9 % antibacterial efficiency against E. coli (ATCC25922), S. aureus (ATCC25923), and A. baumanii (ATCC19606). While nanoparticle accumulation was observed in human primary epidermal keratinocyte (HEKa) cells, no cytotoxic effects were detected in the epidermis. This study highlights the effectiveness of Chl Cu as a dual stabilizing and coordinating agent for Ag⁰ NPs , offering a promising approach for developing antimicrobial surgical materials.