Tannic acid-modified silver nanoparticles as a novel therapeutic agent against Acanthamoeba

Marcin Padzik,Maciej Szmidt,Marta Grodzik,Jacob Lorenzo-Morales,Jarosław Grobelny,Edyta B Hendiger,Lidia Chomicz

doi:10.1007/s00436-018-6049-6

Abstract

Free-living amoebae belonging to Acanthamoeba genus are widely distributed protozoans which are able to cause infection in humans and other animals such as keratitis and encephalitis. Acanthamoeba keratitis is a vision-threatening corneal infection with currently no available fully effective treatment. Moreover, the available therapeutic options are insufficient and are very toxic to the eye. Therefore, there is an urgent need for the development of more effective anti-amoebic agents. Nanotechnology approaches have been recently reported to be useful for the elucidation antimicrobial, antiviral, antifungal and antiprotozoal activities and thus, they could be a good approach for the development of anti-Acanthamoeba agents. Therefore, this study was aimed to explore the activity and cytotoxicity of tannic acid-modified silver nanoparticles, pure silver nanoparticles and pure gold nanoparticles against clinical strains of Acanthamoeba spp. The obtained results showed a significant anti-amoebic effect of the tannic acid-modified silver nanoparticles which also presented low cytotoxicity. Moreover, tannic acid-modified silver nanoparticles were well absorbed by the trophozoites and did not induce encystation. On the other hand, pure silver nanoparticles were only slightly active against the trophozoite stage and pure gold nanoparticles did not show any activity. In conclusion and based on the observed results, silver nanoparticle conjugation with tannic acid may be considered as potential agent against Acanthamoeba spp.

Highlights

Acanthamoeba genus is a widely distributed, free-living protozoa which includes some strains with the ability to causeRegarding Acanthamoeba keratitis (AK), the main key predisposing factors of this infection include contact lens use, corneal trauma and exposition of eye to contaminated water
Summarizing, there is an urgent need for the development of novel treatments that would be less toxic to the eye and more effective against both trophozoite and cyst stages of Acanthamoeba spp. (Clarke et al 2012; LorenzoMorales et al 2015; Padzik et al 2017)
The tannic acid-modified silver nanoparticles (AgTANPs), pure silver nanoparticles (AgNPs) and pure gold nanoparticles (AuNPs) solutions were characterized by transmission electron microscope (TEM) technique

Summary

Introduction

Acanthamoeba genus is a widely distributed, free-living protozoa which includes some strains with the ability to cause. Regarding AK, the main key predisposing factors of this infection include contact lens use, corneal trauma and exposition of eye to contaminated water. No drug has been described as a single fully effective treatment against AK and current therapeutic approaches are restricted to the application of chlorhexidine digluconate combined with propamidine isethionate or hexamidine. Parasitol Res (2018) 117:3519–3525 prolonged treatment with these therapeutic agents is very toxic for the human eye. Summarizing, there is an urgent need for the development of novel treatments that would be less toxic to the eye and more effective against both trophozoite and cyst stages of Acanthamoeba spp. Summarizing, there is an urgent need for the development of novel treatments that would be less toxic to the eye and more effective against both trophozoite and cyst stages of Acanthamoeba spp. (Clarke et al 2012; LorenzoMorales et al 2015; Padzik et al 2017)

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Conclusion