Novel insights regarding the safety and efficacy of pyrethroid-coated nanoparticles against Hyalomma ticks

Tean Zaheer, Rao Zahid Abbas, Tauseef Ur Rehman, Muhammad Kasib Khan, Muhammad Imran Arshad

Nanoparticles have been shown to inhibit major life cycle stages of ticks, indicative of promising application of nanomaterials against the hard ticks. The study thus probed into one of alternative options to curtail Hyalomma by employing nanocomposites consisting of pyrethroids (cypermethrin and deltamethrin) coated nanoparticles of iron oxides and iron sulfides keeping alongside the evaluation of their toxicity through double trial. The nanocomposites used in this study were roughly spherical type of morphology and various size dimensions upon characterization using SEM, EDX and FTIR. The application of nanocomposites on female ovipositioning tick showed a declined to 85% in deltamethrin coated FeO NPs whereas, this decline was up to 18% in Cyp-FeS NPs and up to 5% in Cyp-FeO NPs. Similarly, the larval hatching was also impacted leading to a hatching percentage of 5% and only 1% by application of Cyp-FeS NPs and Cyp-FeO NPs, respectively. Similarly, the larval groups had LC90 of 4.1 and 4.73 mg/L for the Cyp-FeO NPs and Cyp-FeS NPs groups. The delta-FeO NPs and delta-FeS NPs demonstrated a promising effect against adult ticks showing LC50= 3.5 mg/L, LC90= 6.7 mg/L and LC50= 3.8 mg/L, LC90= 7.9 mg/L respectively. MTT assay revealed that the pyrethroids coupled with iron oxide nanoparticles showed least cytotoxicity even at highest concentration (10^-1 µL) among other nanocomposites. The study thus concluded safer spectrum of non- target effects of pyrethroids coated nanomaterials in addition to their significant anti-tick activity.