The Toxic Effects and Mechanisms of CuO and ZnO Nanoparticles

TLDR

Metal‑oxide nanoparticles are increasingly used in catalysis, electronics, sensors, remediation, and biomedicine, yet their environmental release has raised concerns about organism toxicity amid unresolved controversies. This review seeks a comprehensive understanding of CuO and ZnO nanoparticle toxicity to enable their safe application. By examining size, surface properties, dissolution, and exposure routes, the authors link these factors to oxidative‑stress, coordination, and non‑homeostatic mechanisms underlying CuO and ZnO nanoparticle toxicity.

Abstract

Recent nanotechnological advances suggest that metal oxide nanoparticles (NPs) have been expected to be used in various fields, ranging from catalysis and opto-electronic materials to sensors, environmental remediation, and biomedicine. However, the growing use of NPs has led to their release into environment and the toxicity of metal oxide NPs on organisms has become a concern to both the public and scientists. Unfortunately, there are still widespread controversies and ambiguities with respect to the toxic effects and mechanisms of metal oxide NPs. Comprehensive understanding of their toxic effect is necessary to safely expand their use. In this review, we use CuO and ZnO NPs as examples to discuss how key factors such as size, surface characteristics, dissolution, and exposure routes mediate toxic effects, and we describe corresponding mechanisms, including oxidative stress, coordination effects and non-homeostasis effects.