Baiting bacteria with amino acidic and peptidic corona coated defect-engineered antimicrobial nanoclusters for optimized wound healing.

Abstract

Keeping steps ahead of the bacteria in the race for more efficacious antibacterial strategies is increasingly difficult with the advent of bacterial resistance genes. Herein, we engineered copper sulfide nanoclusters (CuS_x NCs) with variable sulfur defects for enhanced dual-treatment of bacterial infections by manipulating photothermal effects and Fenton-like activity. Next, by encasing CuS_x NCs with a complex mixture of amino acids and short peptides derived from Luria-Bertani bacterial culture media as a protein corona, we managed to coax E. Coli to take up these CuS_x NCs. As a whole, Amino-Pep-CuS_x NCs was perceived as a food source and actively consumed by bacteria, enhancing their effective uptake by at least 1.5-fold greater than full length BSA protein BSA-corona CuS_x NCs. Through strategically using defect-engineering, we successfully fine-tune photothermal effect and Fenton-like capacity of CuS_x NCs. Increased sulfur defects lead to reduced but sufficient heat generation under solar-light irradiation and increased production of toxic hydroxyl radicals. By fine-tuning sulfur defects during synthesis, we achieve CuS_x NCs with an optimal synergistic effect, significantly enhancing their bactericidal properties. These ultra-small and biodegradable CuS_x NCs can rapidly break down after treatment for clearance. Thus, Amino-Pep-CuS_x NCs demonstrate effective eradication of bacteria both <i>in vitro</i> and <i>in vivo</i> because of their relatively high uptake, optimal balanced photothermal and chemodynamic outcomes. Our study offers a straightforward and efficient method to enhance bacterial uptake of next generation of antibacterial agents.