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Updated: Apr 21, 2026

A Small-Scale Setup for Algal Toxicity Testing of Nanomaterials and Other Difficult Substances
Published on: October 10, 2020
A colloidal singularity reveals the crucial role of colloidal stability for nanomaterials in-vitro toxicity testing:
Soledad Gonzalo1, Veronica Llaneza2, Gerardo Pulido-Reyes3
1Departamento de Ingeniería Química, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.
Abstract:
Aggregation raises attention in Nanotoxicology due to its methodological implications. Aggregation is a physical symptom of a more general physicochemical condition of colloidal particles, namely, colloidal stability. Colloidal stability is a global indicator of the tendency of a system to reduce its net surface energy, which may be achieved by homo-aggregation or hetero-aggregation, including location at bio-interfaces. However, the role of colloidal stability as a driver of ENM bioactivity has received little consideration thus far. In the present work, which focuses on the toxicity of nanoscaled Fe° nanoparticles (nZVI) towards a model microalga, we demonstrate that colloidal stability is a fundamental driver of ENM bioactivity, comprehensively accounting for otherwise inexplicable differential biological effects. The present work throws light on basic aspects of Nanotoxicology, and reveals a key factor which may reconcile contradictory results on the influence of aggregation in bioactivity of ENMs.
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