School of Geographic Sciences, East China Normal University, Shanghai, 200241, China; School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Environ Pollut. 2023 Jan 1;316(Pt 1):120517. doi: 10.1016/j.envpol.2022.120517. Epub 2022 Oct 26.
The toxic effect of waterborne nanoplastics is a manifestation of bio-nano interfacial interactions. Although nanoplastics with different physicochemical characteristics are known to exhibit distinct toxicities, it remains poorly understood how the properties of nanoplastics affect the bio-nano interface interactions. Here, polystyrene nanoparticles (PSNPs) varying in size (50, 300, and 500 nm) and surface charge (negative and positive charge) were employed to explore the interplay between PSNPs and algal cells (Chlamydomonas reinhardtii), with special focus on the heteroaggregation of PSNPs and microalgae, PSNPs cellular internalization, and cellular physiological responses. Results showed that large-sized PSNPs (300 and 500 nm) caused apparent toxicity to C. reinhardtii, mainly due to light blockage resulting from the PSNPs-microalgae heteroaggregation and the shading effect of PSNPs, which was independent of PSNPs concentrations. However, the toxicity of small-sized PSNPs (50 nm) was controlled by both particle surface charge and particle concentration. The positively charged PS-NH was more readily heteroaggregated with microalgae than the negatively charged PS-COOH, leading to photosynthesis damage-induced toxicity. Increasing the concentration of small-sized PSNPs stimulated the secretion of extracellular polymeric substances, allowing more PSNPs to attach on the cell surface and further to enter the cell, which was responsible for the increased toxicity. These findings provide new insights into how nanoplastics induce contact toxicity in microalgae cells through specific biointerfacial interactions.
水基纳米塑料的毒性作用是生物-纳米界面相互作用的表现。尽管具有不同物理化学特性的纳米塑料被认为具有明显的毒性，但人们对纳米塑料的性质如何影响生物-纳米界面相互作用仍知之甚少。在这里，我们使用不同粒径（50、300 和 500nm）和表面电荷（负电荷和正电荷）的聚苯乙烯纳米颗粒（PSNPs）来探索 PSNPs 与藻类细胞（莱茵衣藻）之间的相互作用，特别关注 PSNPs 和微藻的异质聚集、PSNPs 的细胞内内化和细胞生理反应。结果表明，大粒径 PSNPs（300 和 500nm）对 C. reinhardtii 表现出明显的毒性，主要是由于 PSNPs-微藻异质聚集和 PSNPs 的遮光效应导致的光阻断，这与 PSNPs 浓度无关。然而，小粒径 PSNPs（50nm）的毒性受颗粒表面电荷和颗粒浓度的共同控制。带正电荷的 PS-NH 比带负电荷的 PS-COOH 更容易与微藻异质聚集，导致光合作用损伤诱导的毒性。增加小粒径 PSNPs 的浓度会刺激细胞外聚合物的分泌，使更多的 PSNPs 附着在细胞表面并进一步进入细胞，这是毒性增加的原因。这些发现为纳米塑料如何通过特定的生物界面相互作用引起微藻细胞的接触毒性提供了新的见解。
