Toxicity Mechanisms of Copper-Based Nanoparticles

Copper-based nanoparticles display a multifaceted profile of biological interactions, driven primarily by their high surface area, propensity for rapid dissolution and consequent release of copper ions. Upon cellular uptake, these particles can catalyse the formation of reactive oxygen species (ROS), precipitating oxidative stress and damage to lipids, proteins and DNA. Two principal cell‐death pathways are implicated: apoptosis, characterised by caspase activation and mitochondrial membrane depolarisation, and autophagy, involving the sequestration of damaged organelles. Dissolved copper also disrupts metal homeostasis by binding to metallothioneins and perturbing redox‐sensitive signalling cascades. In barrier tissues, airborne or ingested nanoparticles provoke inflammatory responses, cytokine secretion and, in the lung, extracellular matrix remodelling that culminates in fibrosis. Systemic distribution depends on particle size, surface coating and solubility, with smaller, more soluble forms accumulating preferentially in liver, kidney and spleen. Genotoxic effects arise both from direct copper–DNA interactions and from ROS‐induced strand breaks, while subchronic exposure can damage haematopoietic and immune organs. A thorough understanding of these mechanisms underpins the design of safer nanomaterials and informs risk assessment for environmental and occupational settings.

Research from Nature Portfolio

Inhalation studies in rodent models have demonstrated that pulmonary exposure to copper oxide nanoparticles induces dose‐dependent epithelial cell apoptosis and a marked inflammatory infiltrate. Elevated ROS levels trigger TUNEL‐positive cell death and upregulate collagen deposition and α‐smooth muscle actin, indicative of progressive fibrosis. These findings reveal a clear link between oxidative insult and extracellular matrix remodelling in the respiratory tract. Separately, investigations into copper oxide nanoparticles as anticancer agents have shown selective toxicity towards tumour initiating cells in pancreatic models. Here, particle‐induced ROS generation leads to loss of mitochondrial membrane potential and activation of apoptotic cascades, resulting in significant tumour growth inhibition in vivo. Together, these studies illustrate how a common mechanistic hub—ROS‐dependent mitochondrial dysfunction—can underlie both adverse pulmonary outcomes and targeted antitumour effects.

Toxicity Mechanisms of Copper-Based Nanoparticles publication trend

The graph below shows the total number of articles in toxicity mechanisms of copper-based nanoparticles across all publications each year (not limited to Nature Index journals).

Technical terms

Reactive oxygen species (ROS): Chemically reactive molecules derived from oxygen that can oxidise cellular components.

Oxidative stress: A state in which ROS generation exceeds antioxidant defence, leading to molecular damage.

Apoptosis: Programmed cell death involving caspase activation, DNA fragmentation and membrane blebbing.

Autophagy: Cellular process of sequestering and degrading damaged organelles and proteins in lysosomes.

Dissolution: The release of metal ions from nanoparticles into surrounding biological fluids.

Biodistribution: The pattern of nanoparticle or ion accumulation across tissues following administration.

References

1. MMP-3-mediated cleavage of OPN is involved in copper oxide nanoparticle-induced activation of fibroblasts. Particle and Fibre Toxicology (2023).
2. Antimicrobial Nano-Agents: The Copper Age. ACS Nano (2021).
3. Comparative toxicity and biodistribution assessments in rats following subchronic oral exposure to copper nanoparticles and microparticles. Particle and Fibre Toxicology (2016).
4. Intranasal Delivery of Copper Oxide Nanoparticles Induces Pulmonary Toxicity and Fibrosis in C57BL/6 mice. Scientific Reports (2018).
5. Copper oxide nanoparticles inhibit pancreatic tumor growth primarily by targeting tumor initiating cells. Scientific Reports (2019).