Nanotechnology National Laboratory for Agriculture (LNNA), Embrapa Instrumentação, 13560-970 São Carlos, SP, Brazil; PPG-Biotec, Center for Exact Sciences and Technology, Federal University of São Carlos (UFSCar), 13565-905 São Carlos, SP, Brazil.
Nanotechnology National Laboratory for Agriculture (LNNA), Embrapa Instrumentação, 13560-970 São Carlos, SP, Brazil.
Ecotoxicol Environ Saf. 2017 Oct;144:138-147. doi: 10.1016/j.ecoenv.2017.06.008. Epub 2017 Jun 10.
The advance of nanotechnology has enabled the development of materials with optimized properties for applications in agriculture and environment. For instance, nanotechnology-based fertilizers, such as the candidate hydroxyapatite (HAp) nanoparticles (Ca(PO)(OH)), can potentially increase the food production by rationally supplying phosphorous to crops, although with inferior mobility in the environment (when compared to the soluble counterparts), avoiding eutrophication. Nonetheless, the widespread consumption of nanofertilizers also raises concern about feasible deleterious effects caused by their release in the environment, which ultimately imposes risks to aquatic biota and human health. Nanoparticles characteristics such as size, shape, surface charge and chemical functionality strongly alter how they interact with the surrounding environment, leading to distinct levels of toxicity. This investigation aimed to compare the toxicity of different HAp nanoparticles, obtained by two distinct chemical routes, against algae Pseudokirchneriella subcapitata, which composes the base of the aquatic trophic chain. The as synthesized HAp nanoparticles obtained by co-precipitation and co-precipitation followed by hydrothermal method were fully characterized regarding structure and morphology. Toxicity tests against the microalgae were carried out to evaluate the growth inhibition and the morphological changes experienced by the exposition to HAp nanoparticles. The results showed that high concentrations of coprecipitated HAp samples significantly decreased cell density and caused morphological changes on the algal cells surface when compared to HAp obtained by hydrothermal method. HAp nanoparticles obtained with dispersing agent ammonium polymethacrylate (APMA) indicated negligible toxic effects for algae, due to the higher dispersion of HAp in the culture medium as well as a reduced shading effect. Therefore, HAp nanoparticles obtained by the latter route can be considered a potential source of phosphorous for agricultural crops in addition to reduce eutrophication.
纳米技术的进步使得人们能够开发出具有优化性能的材料，应用于农业和环境领域。例如，基于纳米技术的肥料，如候选物羟基磷灰石（HAp）纳米颗粒（Ca(PO)(OH)），可以通过合理地向作物供应磷来提高粮食产量，尽管在环境中的迁移性较差（与可溶性肥料相比），从而避免富营养化。然而，纳米肥料的广泛使用也引起了人们对其在环境中释放可能造成有害影响的担忧，这最终会对水生生物和人类健康造成风险。纳米颗粒的尺寸、形状、表面电荷和化学功能等特性强烈改变了它们与周围环境的相互作用方式，导致毒性水平存在明显差异。本研究旨在比较两种不同化学途径制备的不同 HAp 纳米颗粒对构成水生生态链基础的藻类假微型海链藻（Pseudokirchneriella subcapitata）的毒性。通过共沉淀和共沉淀后水热法合成的 HAp 纳米颗粒在结构和形态方面进行了全面表征。对微藻进行了毒性测试，以评估 HAp 纳米颗粒暴露对藻类生长抑制和形态变化的影响。结果表明，与水热法制备的 HAp 相比，共沉淀法制备的 HAp 高浓度样品显著降低了细胞密度，并导致藻细胞表面发生形态变化。使用分散剂丙烯酰胺（APMA）制备的 HAp 纳米颗粒对藻类几乎没有毒性作用，这是由于 HAp 在培养基中的分散性更高，以及遮蔽效应降低。因此，与水热法相比，通过后一种方法获得的 HAp 纳米颗粒可以被认为是农业作物潜在的磷源，同时还可以减少富营养化。
