また、ポリビニルピロリドン（PVP）で機能化した銀ナノ粒子のBiomphalaria glabrataに対する軟体動物殺虫活性：統合失調症の中間宿主カタツムリの防除への応用についても検討した

Molluscicidal activity of polyvinylpyrrolidone (PVP)-functionalized silver nanoparticles to Biomphalaria glabrata: implications for control of intermediate host snail of schistosomiasis.

• Paula Sampaio Araújo
• Maxwell Batista Caixeta
• Rafaella da Silva Brito
• Bruno Bastos Gonçalves
• Sueli Maria da Silva
• Emília Celma de Oliveira Lima
• Luciana Damacena Silva
• José Clecildo Barreto Bezerra
• Thiago Lopes Rocha

抄録

銀ナノ粒子（Ag NP）は抗菌性を有することからいくつかの市販製品に応用されているが，その軟体化剤としての特性，作用機序，カタツムリ種に対する毒性については不明な点が多い．本研究では，Schistosoma mansoniの中間宿主である淡水カタツムリBiomphalaria glabrataの初期発生段階におけるポリビニルピロリドン（PVP）官能基化Ag NPとその溶解体（Agイオン）の比較毒性を解析した。複数の手法を用いてAg NPを合成して特徴を調べ、カタツムリの胚毒性を死亡率,孵化率,発達段階,形態学的変化の観点から解析した。その結果，両銀製剤はカタツムリの胚に濃度と曝露時間に依存したパターンで死亡率，孵化遅延，形態学的変化（特に親水性異常）を誘発することが示された。また、孵化したばかりのカタツムリに対しては、Ag NPは溶解したものと比較して胚毒性が低く、同程度の毒性を示した。B. glabrataの異なる初期発生段階に対するAg NPの毒性についての知見は、軟体動物駆除剤としての利用や、シマソーマ症を含む顧みられない熱帯病の防除に貢献するものである。

Silver nanoparticles (Ag NPs) have been applied in several commercial products due to their antimicrobial properties, while their molluscicide properties, mode of action and toxicity to snail species remain unclear. In this study, the comparative toxicity of polyvinylpyrrolidone (PVP)-functionalized Ag NPs and their dissolved counterpart (Ag ions) was analyzed during the early developmental stages of the freshwater snail Biomphalaria glabrata, intermediate host of Schistosoma mansoni. Ag NPs were synthesized and characterized by multiple techniques, and the snail embryotoxicity was analyzed in terms of mortality, hatching, developmental stages and morphological alterations, while the acute toxicity to newly-hatched snails was analyzed by mortality and behavioral impairments. Results showed that both Ag forms induced mortality, hatching delay and morphological alterations (especially hydropic abnormalities) in snail embryos in a concentration and exposure time dependent patterns. Ag NPs showed low embryotoxic effects and similar toxicity for newly-hatched snails when compared to their dissolved counterparts, indicating that the nanotoxicity was dependent of snail developmental stages. The knowledge about the Ag NP toxicity to different early development stages of B. glabrata contributes to its potential use as molluscicide and control of neglected tropical diseases, including schistosomiasis.

Copyright © 2020. Published by Elsevier B.V.