Green Synthesis and Characterization of ZrO₂ Nanoparticles: In Vitro Efficacy Against Echinococcus Granulosus Protoscolices

Abstract

Background: Cystic echinococcosis (CE), caused by the parasite Echinococcus granulosus, represents a significant global health challenge, necessitating the development of innovative and effective therapeutic strategies. This study aimed, for the first time, to biosynthesize zirconium dioxide nanoparticles (ZrO₂ NPs) via a green route using an aqueous fruit extract of Tribulus terrestris, characterize them, and evaluate their in vitro scolicidal efficacy against E. granulosus protoscolices.

Methods: The synthesized ZrO₂ NPs were comprehensively characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (FESEM-EDX), zeta potential analysis, and UV-visible spectroscopy (UV-Vis). The scolicidal activity was assessed by exposing protoscolices to various concentrations of ZrO₂ NPs (50–200 µg/mL) for different time intervals (5–60 min). Albendazole (100 µg/mL) and phosphate-buffered saline (PBS) were used as positive and negative controls, respectively.

Results: XRD analysis confirmed the crystalline nature of the ZrO₂ NPs in a cubic fluorite structure with an average crystallite size of ~47.7 nm. FESEM images revealed quasi-spherical particles with a mean diameter of ~48 nm, while FTIR and EDX analyses indicated their successful capping with bioactive compounds from the plant extract. The ZrO₂ NPs exhibited significant concentration- and time-dependent scolicidal activity (P < 0.001), with the 200 µg/mL concentration achieving 100% mortality after 60 min. The median lethal concentration (LC₅₀) was 67.8 µg/mL after 60 min. The scolicidal efficacy of ZrO₂ NPs (at ≥150 µg/mL) was significantly higher than that of albendazole (P < 0.001).

Conclusion: This study is the first to report the use of T. terrestris extract for the biosynthesis of ZrO₂ NPs and to evaluate their scolicidal activity against E. granulosus. The results indicate that biosynthesized ZrO₂ NPs possess promising in vitro therapeutic potential, positioning them as a viable candidate for developing alternative or adjunctive therapies for CE. Further in vivo studies are warranted to assess their clinical efficacy and safety.