Department of Comparative Biomedicine and Food Science, Agripolis Campus, University of Padua, viale dell'Università 16, 35020 Legnaro, Italy; Department of Physical Chemistry, Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 78371 Olomouc, Czech Republic.
Department of Biology, University of Padua, via U. Bassi 58/b, 35121 Padua, Italy.
J Photochem Photobiol B. 2019 May;194:21-31. doi: 10.1016/j.jphotobiol.2019.03.004. Epub 2019 Mar 13.
Aedes aegypti mosquitos are widespread vectors of several diseases and their control is of primary importance for biological and environmental reasons, and novel safe insecticides are highly desirable. An eco-friendly photosensitizing magnetic nanocarrier with larvicidal effects on Aedes aegypti was proposed. The innovative core-shell hybrid nanomaterial was synthesized by combining peculiar magnetic nanoparticles (called Surface Active Maghemite Nanoparticles - SAMNs, the core) and chlorin-e6 as photosensitizer (constituting the shell) via self-assembly in water. The hybrid nanomaterial (SAMN@chlorin) was extensively characterized and tested for the photocidal activity on larvae of Aedes aegypti. The SAMN@chlorin core-shell nanohybrid did not present any toxic effect in the dark, but, upon light exposure, showed a higher photocidal activity than free chlorin-e6. Moreover, the eco-toxicity of SAMN@chlorin was determined in adults and neonates of Daphnia magna, where delayed toxicity was observed only after prolonged (≥4 h) exposure to intense light, on the green alga Pseudokirchneriella subcapitata and on the duckweed Lemna minor on which no adverse effects were observed. The high colloidal stability, the physico-chemical robustness and the magnetic drivability of the core-shell SAMN@chlorin nanohybrid, accompanied by the high photocidal activity on Aedes aegypti larvae and reduced environmental concerns, can be proposed as a safe alternative to conventional insecticides.
埃及伊蚊是多种疾病的广泛传播媒介，出于生物和环境原因，对其进行控制至关重要，因此迫切需要新型安全的杀虫剂。本研究提出了一种对埃及伊蚊具有杀幼虫作用的环保型光敏磁性纳米载体。通过水相中的自组装，将特殊的磁性纳米颗粒（称为表面活性磁赤铁矿纳米颗粒-SAMN，内核）和叶绿素 e6 作为光敏剂（构成外壳）结合起来，合成了创新性的核壳混合纳米材料。对混合纳米材料（SAMN@chlorin）进行了广泛的表征和对埃及伊蚊幼虫的光杀活性测试。SAMN@chlorin 核壳纳米杂化物在黑暗中没有任何毒性作用，但在光照下，其光杀活性高于游离叶绿素 e6。此外，还在大型溞成体和幼体以及水华鱼腥藻和浮萍上测定了 SAMN@chlorin 的生态毒性，只有在长时间（≥4 小时）暴露于强光下时，才观察到延迟毒性，而在这些生物上没有观察到不利影响。核壳 SAMN@chlorin 纳米杂化物具有高胶体稳定性、物理化学稳定性和磁性可驱动性，对埃及伊蚊幼虫具有高光杀活性，且环境担忧较小，可作为传统杀虫剂的安全替代品。
