Effective targeting of pathogenic Acanthamoeba castellanii of the T4 genotype using nano-formulations of Quercetin

Abstract

The incidence of infections caused by pathogenic Acanthamoeba is increasing, yet the prognosis continues to be poor. Acanthamoeba spp. are responsible for causing a blinding keratitis and a fatal granulomatous amoebic encephalitis. Due to limited options for the treatment of Acanthamoeba infections, there is a need for the development of effective drugs, which can target Acanthamoeba species. Zinc-copper nanoparticles show antimicrobial effects and enhance the effectiveness of their payload at specified biological targets. In this study, we used Quercetin and its' nanoconjugates and tested their anti-acanthamoebic properties. Quercetin was conjugated and loaded onto tragacanth polymer (a bioadhesive gum) coated with zinc copper bimetallic nanoparticles (QUE-TRG-ZnCuNPs) to enhance effects against Acanthamoeba castellanii. The characterization of the nanoconjugates was accomplished through fourier-transform infrared spectroscopy, ultraviolet visible spectrophotometry. Zeta potential, particle size, polydispersity index, scanning electron microscopy with energy-dispersive X-ray analysis were accomplished. Quercetin alone and its nanoconjugates were tested for the viability and growth of amoeba, encystation and excystation activity against A. castellanii, the cytopathogenicity assays were conducted to understand amoebae-mediated cytopathogenicity on host cells. The findings revealed that QUE-TRG-ZnCuNPs displayed significant anti-amoebic properties, including encystation and excystment and enhanced the effects of Quercetin against A. castellanii. Furthermore, QUE-TRG-ZnCuNPs reduced amoebae-mediated cytopathogenicity on host cells. Thus, Quercetin, combined with nanotechnology, could provide an effective strategy in the rationale development of therapeutics against Acanthamoeba infections.