Shell crosslinked nanoparticles carrying silver antimicrobials as therapeutics

Abstract

Amphiphilic polymer nanoparticles loaded with silver cations or/and N-heterocyclic carbene-silver complexes were assessed as antimicrobial agents against Gram-negative pathogens Escherichia coli and Pseudomonas aeruginosa.

Fig. 1

Schematic representations of (a) SCC10 (yellow ball) incorporated into the core and Ag⁺ (blue ball) from AgNO₃ chelated into the shell of an SCK prepared from PAA₁₃₀-b-PS₄₀; and (b) AgNO₃–SCK, SCC10–SCK, and AgNO₃–SCC10–SCK or SCC10–AgNO₃–SCK. Note: the placements of the silver species within the SCK framework are hypothetical locations, which have not been confirmed experimentally.

Fig. 2

TEM images of SCKs and silver-loaded SCKs, each with negative staining by 1% phosphotungstic acid, (a) SCK, (b) AgNO₃–SCK, (c) SCC10–SCK, (d) AgNO₃–SCC10–SCK, and (e) SCC10–AgNO₃–SCK. The scales are consistent.

Fig. 3

Release profiles of silver from silver-bearing nanoparticles at 37 °C in 5 mM PBS at pH 7.4 (duplicate).

Fig. 4

Inhibition of growth of E. coli strain UTI89 (a) and P. aeruginosa strain PAM57-15 (b) by silver-bearing nanoparticles and naked AgNO₃. Relative optical density (650 nm) after 6 h is shown for each construct at the indicated silver concentrations.